Designing Real-life Structures with Etabs | Wahid Elgohary | Skillshare

Playback Speed

  • 0.5x
  • 1x (Normal)
  • 1.25x
  • 1.5x
  • 2x

Designing Real-life Structures with Etabs

teacher avatar Wahid Elgohary, CPEng NER MEng Structural Engineer

Watch this class and thousands more

Get unlimited access to every class
Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Watch this class and thousands more

Get unlimited access to every class
Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Lessons in This Class

40 Lessons (7h 33m)
    • 1. Introduction

    • 2. Working with Models

    • 3. Defining Storeys

    • 4. Defining Grids

    • 5. Defining Materials

    • 6. Defining Sections

    • 7. Modifying Stiffnesses

    • 8. Drawing Columns

    • 9. Drawing Walls

    • 10. Drawing Walls Part 2

    • 11. Drawing Walls Part 3

    • 12. Drawing Slabs

    • 13. Drawing Beams

    • 14. Meshing and Releases

    • 15. Model Check and Verification

    • 16. Gravity Loads

    • 17. Wind Loads

    • 18. Earthquake Design

    • 19. Static Earthquake Design

    • 20. Dynamic Earthquake Design

    • 21. Load Combination

    • 22. Load Combination Part 2

    • 23. Piers and Spandrels

    • 24. Gravity Load Checks

    • 25. Wind Load Checks Part 1

    • 26. Wind Load Checks Part 2

    • 27. Wind Load Checks Part 3

    • 28. Static Earthquake Part 1

    • 29. Static Earthquake Part 2

    • 30. Static Earthquake Part 3

    • 31. Static Earthquake Part 4

    • 32. Dynamic Earthquake Design

    • 33. Columns Design Part 1

    • 34. Columns Design Part 2

    • 35. Wall Design Part 1

    • 36. Wall Design Part 2

    • 37. Walls Design Part 3

    • 38. Precast Walls Checks

    • 39. Advanced Grid Systems

    • 40. Piles Vs Pins

  • --
  • Beginner level
  • Intermediate level
  • Advanced level
  • All levels
  • Beg/Int level
  • Int/Adv level

Community Generated

The level is determined by a majority opinion of students who have reviewed this class. The teacher's recommendation is shown until at least 5 student responses are collected.





About This Class

A practical course on modeling, analyzing, and designing concrete buildings in Etabs based on real-life projects' workflow. I have put together this course with the aim of helping you to understand the concepts and technicals behind the structural design of buildings using the software Etabs. Throughout this course, we will be going through a unique office building project that is incepted based on actual real-life structures that I have worked on across Southeast Asia, the Middle East, and Australia.

I will take you through modeling the building in etabs and expand on finite element analysis concepts throughout to help you develop a deeper understanding of the fundamentals behind the black screen. We will then define our gravity as well as lateral loads on the building, namely wind and earthquake, both code-static forces and dynamic response spectrum.

We will verify the analysis results via simple hand calculations and checks to common rule of thumbs for buildings design, and finally, design the columns and the walls in the building. I will be going through the design process for the first time on this project with you through the course, with unfiltered decision making and commentary on my thoughts and rationale behind the design decisions I am making, taking into account things like including industry expectations, common practices, and rationalization in design. Finally, we will present our report of the detailed design using etabs report function.

You will need to have access to etabs software on your computer to practice throughout the course. You can request for evaluation version from the CSI website

Meet Your Teacher

Teacher Profile Image

Wahid Elgohary

CPEng NER MEng Structural Engineer


Hello, I'm Wahid. A Structural Engineer with professional experience in the design of residential and commercial high-rise towers in Melbourne, Adelaide, Kuala Lumpur, and Bangkok.


See full profile

Class Ratings

Expectations Met?
  • Exceeded!
  • Yes
  • Somewhat
  • Not really
Reviews Archive

In October 2018, we updated our review system to improve the way we collect feedback. Below are the reviews written before that update.

Why Join Skillshare?

Take award-winning Skillshare Original Classes

Each class has short lessons, hands-on projects

Your membership supports Skillshare teachers

Learn From Anywhere

Take classes on the go with the Skillshare app. Stream or download to watch on the plane, the subway, or wherever you learn best.


1. Introduction: Hello, my name is Rohit and unchartered structural engineer with a passion for designing high-rise building. I've put together this course to help you understand the technicals and fundamentals of engineering concepts and design behind using e-Types. The software that we're gonna be jumping on in few minutes. I've created a project from the previous experience of the real life for things that have worked on in Asia, Australia, and the Middle East. I'll take you through the detailed design of the building and the concepts behind finite element analysis and design in E tabs to help you understand, in a deeper sense, the meaning of the values that we input in the software. And how to interpret the results of the software more than just using the software as a black box. We will first create our model from scratch. So we will go through saving the model, inputting our materials, our sections, our load types, and then defining our stories, our grids. And then we're gonna go through and create our columns, beams, floor slabs, walls in the building. And then we'd go and assign our loads, including the gravity loads, automatic wind loads to eat tabs. And then we're gonna go through the static and dynamic earthquake load assignments and then analysis. Once we've created the model and carried out our analysis, the first thing that we're gonna do is verify our design by hand using simple hand checks, as well as common rule of thumbs for buildings design. When we're happy with the results and we have the confidence in the analysis that we have achieved so far using ETFs. Then we'll jump into designing our walls and our columns. And we're going to create a report of our design using spreadsheets that we are going to export from e-Types. I'm a big fan of muscle memory. So I would highly suggest that you work through the model by yourself. Actually, I would suggest that you go and create the model by yourself following the step-by-step lectures that we're going to go through now. Because that is actually going to help you learn it much faster. And for that, you'll need to have a computer with ETag software installed on it. If you don't have that right now, you can request for an evaluation version from CSI with the link in the video description below. I've also added few quizzes that will help you to reinforce the main concepts and clarify the most common confusions that the end of each chapter. Lastly, I'd also recommend that you learn with the mindset of teaching this to someone else. Later on, I personally find that this helps me to increase my learning capacity. And I hope that it does increase yours as well. Let's not take too long of a time over here. So lastly, if you have any questions, just drop them into the course and I'll do my best to get back to you as soon as possible. I always enjoy an intriguing question that leads to a greater outcome for me, for you and for everyone else it's joining this course. So without any further ado, let's jump into the computer and start with our goals. 2. Working with Models: Hello everyone. Today we'll be starting with setting our e-Types models. So let's go ahead and create a new file, a new model. And let's use the saved UserDefaults that things that we set up in the previous lectures. Don't worry too much about this. Let's just set it to one story right now and just leave the grids and as they are, as we're going to edit that later on and we add more grids. So don't worry too much about that. Let's just click OK and get going. Alright? So the first thing you wanna do when you have the model in before you do any work is you want to save it somewhere. You're going to be able to access it anytime. Now when I say that, I say that because saving e-Types files on network servers can be a nightmare because when you don't eat tabs, it creates a lot of files when it's computing the analysis of the building. So when that happened, it keeps creating an huge files that could go up to one or two gigabytes of size. What I would highly recommend is make sure that you save it on your hard disk. So it's faster to access this information and write it as you go through the modelling and the analysis. If you don't want to leave the computer on him for two days. And I would highly suggest that you have an SSD disk on your device, which actually speeds up the analysis a lot because of the foster writing or deleting speed. Also another tip is that make sure you are using the correct version of IE tabs that you are going to be consistently using for a long time. And the reason I say that is because e tabs a files are not backward compatible. So if you save this in this current e-Types version of ETH 1.1.1, you cannot open this model on another ETags license, that's an older version, say 18.1. And that might be an issue if you have different licenses on different PCs, make sure that you're always using the same update from E tabs. So you don't run into compatibility problems and you'll have to create the HO model again from scratch or just created from a text file and some things will be missing pretty much. So that being said, let's go ahead and save our file in somewhere that we can access easily as click save. And let's say we don't our documents for this case. Usually I don't like to save it in a general folder, so you have to create a specific folder for that e-Types model. Also for the reason that e-Types creates a lot of files. So if you save the file on the desktop and you run the analysis and you look at the desktop, you're gonna find like 100 files on your desktop. Let's create a new folder for this and call it the best Office github project. And also what I like to save my, my models is I like to have a backup of the model in case if I change something by mistake and I couldn't go back to an older revision of the model. Now, e-Types doesn't back up the models for you automatically. So you have to be smart about doing these things. So what I'd like to do is first revision number. So I start with r one for example. And let's say this is the project number, project 20-20, 0-1. Let's call it the best office project. Now when I change some things in the future, or whether there's some changes that happened because of design coordination with the architect or some analysis that you're changing in your building. You will change the revision instead of overwriting the original model. So you always have the original model that you built that you could quickly use and change some things and rerun it to check some, some of the design situations. Instead, if you keep playing with the main model all the time, at some point you can go back after editing something, especially after you run the analysis, you cannot get back the old model because it overrides the original model. So be very careful about this. Always have at least one models if there's a backup. And do all of your design analysis situations in another model to make sure you don't mess up the original one. So let's go ahead and click save. Now we've got the modal saved n. We are ready to go see you in the next lecture. 3. Defining Storeys: Hello again. So we save the file and now we are pretty much ready to start defining our stories. So we'll go to Edit, Edit stories and grid systems. And we'll start. It can either go to modify the story that's an added manually over here. Or you could use the quick function of quickly adding a story until you reach the number of toys that you're after. And in this case, we'll be looking at eight storeys plus roof starting from the ground as you base. So let's go ahead and make sure we have eight storeys plus a roof. And what he could do is modify the height of each story, which in this case is 3.8 meters per flow. For all of them. Now, that's a bad manual way except for the ground floor which is 4.14.5. Now, another better way to do this, so I'm going to cancel and show you a faster way is let's just cancel and be careful that if you cancel something, it's gonna get cancel the stories are not going to be there. So let's go back to Edit stories and grid systems. But this time, let's go to modify, show Story data instead of quickly adding a story. So let's go here and right-click on the left-hand side and click Add story. And we're going to keep the existing storey heights. Now it's gonna ask me what's the height required for each of these news stories that I'm adding. And that's going to be 3.8 meters. Flow to flow. And it asks me how many stories we're adding. So we're gonna be adding eight storeys plus the existing one to add up to a total of nine stories. And we're going to insert it above the current story. And we're going to be copying from level one now that's a helpful function if you've already modeled your, your flow plate or your slabs and column layout for one flow. And you just want to copy it, say for 20 storey building or a 30-story building. But also there is another smarter way to do that, which is using the similar floors function when you're modelling. We're gonna touch on that later on. Let's just leave it as set from the story one for now. And you'll notice that what it's doing is that it's generating the stories in the background. So it's done generating our stories. And let's just edit our ground floor, which is of a higher 4.5 meters. Now we have that. Usually be careful with the ground floor heights. They usually higher than the other floors. And that's a common design situation. Another one that we'll look at later on is whether that's a master story or not a master story. But we'll touch later on that when we start modeling our building, let's just leave them all as master stories and click OK. Don't forget to click Okay to make sure that this change happen in your model. Alright, so there we go. We've got our stories defined. Next, we are going to be looking at our grids. 4. Defining Grids: Now that we've got our stories in, let's start looking at inputting the correct grids that we are going to be modelling the structure too. So let's go to Edit, Edit stories and grid systems. And let's modify the existing grid. So let's call this the main grid, just to differentiate it from the other grids that will be setting on later on. And E-Types has some really cool functions where you could actually rotate the main grades if you've got a building that's related, even that this might be the case on plan out highly suggest that you keep your model to x and y and don't stick to the rotated geometry. But in this case, we're just looking at a simple x and y grid. I personally like to work with. Display the grid spacing. So let's change that to spacings. Let's look at what's our grid spacing. So in the x-direction, we've got eight meters or 9.5 meters, and the last one is eight. We've got a total of six grids. So let's go on to ETags. Let's have our six grids, 123456, and let's put our last first grid spacing to eight. So this spacing is basically between your first grade and second grade. That's eight. And all of the other intermediate ones are basically 9.5. apart from the last one, whereby a comes back to just eight meter spacings. How about our grids in the y direction? So in the y direction we've got a, B, C, D, E. And similarly the internal ones 9.4 and the external ones are eight. So let's go ahead and input that. Similarly, we started with a, b, c, d, And let's add E. We've got a spacings of eight and internal spacings of 9.5. with edge spacing of eight. If you notice for my last grid, there is no spacing because after my grid e, There is nothing. So it should always be 0. And also if you notice for the y-direction, ETags grid starts at the bottom and they go up. So just be mindful of that we inputting the grids. Now for these ones are not going to change the bubble locations. Let's just make sure that we click OK. And I'll click OK again. So our grids gets updated. Now as additional to the main building grids, you'll find that in all of situation you'll need to define additional grids for your core walls or for additional walls in your building. Just because that's a very effective way to look at the stresses and the results later on in the building. And alcohol isn't just that. Our collocations are off the grid, which is situationally the case in buildings. And this might complicate setting up the wall locations correctly if you're not using the grids function. So let's stick to using the grids and see what's the advantage of that. For the purpose of this exercise, we're gonna call this one core one, and we're going to call this call to. So let's start with core 1 first. And let's go to our ETags model to input additional grids. So we go to Edit grids and let's add a new grid. For this one. We're going to call it core one grid. And it asks us what is the global X and Y location of these grids. So if you recall, when we set up our original grids and E tabs, this is the origin here on the bottom left corner of your grid. And for any grid that you're going to set, you can actually choose how much is that offset from your Y location in the x direction. And how much is it offset in your, from your x location in the y-direction. So let's take those measurements from our drawings. You can see that our X offset from this wireline is 13.5 meters and our y offset to the bottom line is 12.913.512.9. And our grid is perfectly orthogonal so you don't have any rotations and our grades. Now, how many grades do we have? We've got one here, two here, 34. And this is Let's just input that as 2.7 spacings and we could edit the other one later on. And in the y direction, we've got two grids that are 3.1 meter apart. So we'll put two grades, 3.1 meter apart. Now the grit labels don't matter in this case because that's not the actual building grids is just modelling grids that we using to reference in our analysis and design. So let's click OK, and let's open those grids. Remember that spacing that we talked about and we didn't actually modify because we use the typical grid spacing would just go here, modified the spacing to 2.6. And we're good to go. Let's click OK and let's click okay to see we got the correct location approximately. Yeah, we do. All right, let's go ahead and add our second core grid. Similarly, which can add a new grid. We kind of call this core to grid. And we've got the offsets from the original grids, which is 3.519. Let's check our grids in the x and y direction. We've got 123 grids and acts and two grids and why? And the spacing is a little bit unusual, so we're just gonna have to edit that manually. So let's put 23 and x two in the y, 2.7 and the x and 3.1 and the y. But we're going to again have to open it and adjust that spacing between the grids B and C, which is this one. And according to our measurement tools, that is 5.3 meters. So let's input that as 5.3. And now it looks about right. Let's click okay to make sure that we've got it in the correct location. Yep. That looks like it. So now we've got our main building grids. We've got our core one grades, we've got our core two grids, and we're good to go. 5. Defining Materials: Now we are ready to define some material properties that we are going to be using in our e-Types model. Let's go over to the fine material properties. And you'll notice that we have for materials by the full deck comes in the ICAPS model and they're all to the American code. If that's the code that you're designing to stick to these properties. But you're not. Let's go ahead and add a new material. So for me, I'm based in Australia. There is unfortunately no Australia in the regions, but there is New Zealand, which is fairly close in terms of the material properties and the construction. So it's a good start to define to the New Zealand code. Let's start with a concrete. And let's define a 40 MPA concrete grade, which is the most common concrete grade that we're gonna be working with throughout the building. Now. And let's call this 40 MPA. Fc dash. The weight is 24 kilonewton per meter cube and our modulus of elasticity should be adjusted to the concrete cold. So if you look at table 3.1.2 AS thirty six hundred and two thousand eighteen, you will see that the modulus of elasticity for 40 MPA concrete grade is 32,800 megapascals. So let's change that into our material properties. We'll leave our poisons ratio as 0.2, and we'll leave our coefficient of thermal expansion at one times ten to the power of negative six. Let's check our material property design better and make sure that's correct. Concrete grade, which looks like it is. Non-linear material data is usually where you defined your strain limits if you are doing a nonlinear designed. But we're not going to be doing that design here in Australia, and it's beyond the limits of this course. So we're going to leave that one out. Additional material damping is where you would be defining your damping ratio for the concrete. It's a helpful in situations where you have a composite building construction any you have different damping properties for the steel frames and for the concrete cause or the concrete shear walls. But other than that, if you have only one type of structural material in your construction and in your lateral load resisting system out. Just not to put the damping ratio in here and instead just define it in the earthquake analysis. Like how are we going to do later on in this project? So let's leave that as 0 and will input our damping ratio later on. The time-dependent properties is related to the creep and shrinkage behavior of concrete with time. Now, that is very helpful if you are designing post tension slabs and if you are looking at construction sequencing or axial shortening between different columns and the concrete core walls, which is often very sensitive topic in super tall buildings. And that's something that we're gonna be covering later on in this course. So let's define our creep and shrinkage properties to the concrete just to make sure that we have that on hand when we start analyzing it. We're going to leave our creep analysis to be a full integration and we are going to change our time-dependent type to our Australian code. Now maybe disappointed that they're not supporting the new Australian code yet. While they supported for design, but not for, for creep and shrinkage. So we're going to have to use AS 3602,009 for the time being until they get that updated. Let's look at our basic creep coefficient. So if we pull out our AS3 602,009, Table, and look at 40 MPA concrete grade, we'll see that our basic creep coefficient is 2.8. So let's input that into our e-Types. Neither creep and shrinkage behavior of concrete depends on the environment that it's exposed, exposed to. And we're going to be using it to design our core walls and columns, which are going to be exposed to the external environment for a long period during the construction, before the facade comes in. For that purpose, we are going to leave it as a temperate inland or tropical if you're very near to the, say, one way to quickly see the effect of the shrinkage on the concrete is to actually look at the plot here. So if you change this to a shrinkage strain plot, you can see that most of your shrinkage strain happens during the first two to three days of loading. And we know for a fact that after they put the columns and the concrete cause they're gonna be exposed for a period that's at least two to three days before they can put the facade for the lower floors. And that confirms why were going with a temperate and tropical and not interior environment, even though that's gonna give us a bigger shrinkage of the concrete with a basic drying shrinkage strain. Again, we're going to refer back to our AS3 602,009. But this time we're gonna go to this equation, So for this equation, we have a final basic drying shrinkage strain, which pretty much depends on the local aggregates. So it's 800 for Sydney, 900 for Melbourne, and 1000 everywhere else. Since some Bayesian Melbourne will assume that this project is also based in Melbourne. And we're gonna use the 900. So if you put 900 times ten to the six here and 40 MPA concrete grade, you should be getting something like 612 times ten to the power of negative six. Let's input that into our e-Types material properties. And you can enter it as 612 E, which stands for exponential minus six, which stands the power of negative six. And if you click okay, and he opened it again, you'll see that it's actually inputted to the correct decimal place. Let's click OK. And another. Okay. Now we're going to repeat this process for the other concrete grades, like the 5065 MPA concrete grade if we are going to be using them, or the 32 MPA as well. But for our purposes, discourse legit, skip that and let's add the material properties for the rebar. Similarly, we're gonna change the material that we're adding here to a rebar material. And we're going to choose the Australian, New Zealand code. And we're going to choose great 500. Now if you notice, New Zealand uses a Grade II, which has a bigger elongation to help with the utility for the seismic design of the buildings there, because they are in a region of a higher seismicity. However, in Australia we only use great 500 m. So we gotta edit some of the properties here, like the modulus of elasticity, which is only a 200, our weight stays the same, or coefficient of thermal expansion stays the same. And our yield strength and ultimate strength also stays the same. So let's click okay. And again, we're not editing the non-linear material data or the damping ratios like what we did with the concrete. Let's click OK. And OK and save or model. See you in the next lecture. 6. Defining Sections: So now we are ready to start defining our sections for the building. Let's go over to define section properties and let's start defining first our column sections, which are frame element. You'll see that by default, e-Types comes with four sections that are too American standard. But let's just leave it in there and add our sections. So go to add new property. And we're going to choose a concrete rectangle because we are doing a 450 by 450 square column. Let's call this one C1 dash 450 by 450. And the concrete grade, which is a 40 MPA. So at material, we're going to choose our correct concrete grade, which is 40 MPA. And for our section dimensions will need to input that as four hundred and fifty and four hundred and fifty. Now, we can also modify few properties for this section, but we'll touch later on on that. Let's just input the reinforcements for now. So we are designing it as a column, which means it's designed for compression and moments on the two axis. And the bars that we're going to be designing, it's our group 500 bars. Our column reinforcement is rectangular. And this reinforcement is to be designed. Now, if you already have this section designed somewhere else and you want to eat apps to check it for you. You take this reinforcement to check and you will input your reinforcements and cover. But in this case we haven't designed with yet, so just leave it to redesign. I will cover is fairly mill. And we'll just leave it with three bars on each phase of end-to-end. And are ten lakes at 300 with four legs for the confinement. Let's click OK. And you'll notice that the section shape looks slightly different now. And let's click OK. And I'll see you at our cone section is defined. Let's click OK and save. Now let's define our slab section. So we'll go to the define section properties, lab sections. And let's add a new property unless define our 200 bt. And I always like to call up with concrete grade just to make sure that I can know what concrete grade is defined to this section without having to go and open the properties of the section. So we'll leave it as 40 MPA and let's select the correct material, which is a 40 MPA. Now the modelling type, most of the time, you'll only need to work with shell thin shell thick A's when you have a very thick transfer slab that is 900 or one meter or more, and you need to consider the shear deformation of the slab. Membrane is a membrane element that doesn't bend on its weak axis. It only takes load on its strong axis by coord. Although realistically the world's still bans on its weak axis, but the load carrying properties is predominantly in the plane of the wall, not honest, weak axis. Otherwise it become the slab and the code will actually ask you to design it like a slab. But one benefit of using a membrane element for slabs is that it saves a lot on the computational time because it doesn't measure, doesn't consider the bending on the weak axis. So what you might do is you might actually define your slabs as membrane elements just to enable the model to run as quickly as possible and to get your load run down and your lateral earthquake loads. But be careful if you have n slab, that is a transfer slab or enslaved that's used as a part of strontium transfer in your structure. You might not be getting the correct results. Yes, you will be saving on time in running the model, but there might be some inaccuracy in the model that you might not pick up with the eye. So always recommend that you stick with the shell thin elements for your slabs unless you have a very convincing reason to do otherwise. For the type. Etags can model slabs and it can also model drop. So a drop is when you have a flat slab and you have a drop panel around the columns, the difference between a slab and then drop is, the drop is going to be additional to your slab. We model it on the plan, so it's not going to duplicate on the slab sections. But if you have a slab and a slab, any overlap the two slabs in the modeling, that will actually result in duplicate weight. Stiff element is when you have variation that is stiff. For example, if you have a huge pile that's, let's say two meters, and you could sit anything on top of it. And you don't want this lab to take these moments because they are directly bearing on the element below. Stiff is exactly that. It doesn't take bending moment into account when you are running the slab design on e-Types. That's again for slab and waffle slabs. Those are pretty self-explanatory in our case. And most of the time you're going to be only using slab. So we'll go ahead and stick to slide. And our thickness is 200. Let's click OK. And OK and save. Now, define our slab. Now let's go ahead and define our walls. Let's go to the define section properties, wall sections. Now, let's add a new property and let's call this W 200, fc dash 42, Call W2 100. One distinction if you're going to change some of the properties later on. Now, let's put our war material to 40 MPA. Modelling type is very similar to what we had on slabs. And that's because of the fact that ETags model walls and slabs as exactly the same element. They just give you the results a little bit with different sign convention. But what you're looking at over here is shell thin shell thick membrane and layered, which is exactly the same like what we've had for slabs. So most of the time you'll be using a shell thin elements for your walls. Or if you really, really have a compelling case to run the model faster, you could switch to membrane elements just to get your results faster. But let's live with the shelf and modifiers is something we're gonna go through later on. And lets him for our thickness of 200. Now if you notice there is an option here that was also included in our columns which says Include Automatic Christian zone over the wall. Now that's beneficial if you are designing the slabs from E-types because what it does is it recognizes that the wall section is a rigid element, is the support element. So it takes your design moment at the face of that support, instead of the peak moment at the center of the support. Which might make a bit of a difference. If you have very long spans that are continuous internally to our thick that on if I'm designing my slab only tabs. But I'm not in this case. I'll just leave that as off and click OK. And click okay, set the model. And see you in the next lecture. 7. Modifying Stiffnesses: Now before we move on from our sections, it's important to understand the cracked stiffness of our sections that we are using in the model. So if you look at ALS 3600, uh, pretty much gives you the stiffness of the section as a proportion of the gross stiffness of this action if it wasn't correct. And for beams and slabs, that's about 40% of your gross sections stiffness. For columns, it could be as much as 80% or as little as 34% walls, it could be as much as 40% or as little as 25%. Now I know that these values are different for American codes, for example, flat slabs are what? Only 25% and columns are, 0.7, which is 70%. Walls is about 35%, so it's somewhere in-between and this limit of different approaches between the two codes in terms of these factors, which is, so just be mindful of which code you're designing to. But either way the process is the same. So let's look at how we can input these differences into our sections from the beginning. So if you go again to where we define our sections, which is under the define section properties. Let's start with our column sections which are frame. That's the column we defined. So let's go to modify property. And it's under here that we could actually modify the stiffness of that section. So let's click when you modify modifiers. And it's the torsional constant, the moment of inertia about access to a moment of inertia about x three that you will be reducing if you find your column section to crack. Now, how do you know if your compensation is going to be crack? That's a good question. If you look in the Australian Code under Section 8.5.3, you will find this equation for calculating the effective section of your beams slabs. And it also applies for columns when he wanted to calculate the deflections. So your cracking moment is over here. That's this expression for the cracking moment. And basically you can evaluate it on a case to case basis. I've created a spreadsheet that you could use to just input some parameters of your sections and your design actions to actually know straight away if it's going to be cracking or no. So let's input. For column sections. We've got a width of 450 and a length of 450, and we're using 40 MPA. Concrete grid obviously is not pre-stressed. And let's assume that we're just using the minimum reinforcement of 1% in our column, which means 50% is going to be in the tension side of the column and 50% is going to be in the compression side because our enforcement is spread throughout the column section. So we'll put 50.5% invention, 0.5% in compression. And our final design shrinkage is just taken from a is 3600. I just took a quick screenshot of it and put it here just for easy reference. So since we are using a 40 MPA concrete grade and we're looking at a 450 column that's about 450 times ten to the negative six final design shrinkage strain. So put that one here and we can get what we call a cracking moment for our column. So later on we're going to be looking at the column moments under different loads. And if all moment exceed this 39.7 kilonewton meter, that means that this section is going to be cracked. And what happens when it's cracked is that you've got a manually reduced stiffness of your section by how much? Depending on the compression load that you have on the column. So it could be as much as 80% or as much as 30%. And that's one. The second part of the spreadsheet comes in handy when you input how much is your compression load? And based on that, it works out. What's your effective stiffness of the column? In this case, it was about 42%. So once you know what is your effective stiffness? If you'd column cracked, you're gonna go and inputted in here for the column section as 0.42 and also for the torsional constant. So that basically reduces your stiffness in the weekend. Strong access to only 42% of the gross section. That is not cry. Now. Now going to define here, because I don't know if my section is going to crack or not, so I'm going to leave that as one. And we will revisit this later on when we start looking at our results and analyzing and updating that and rerunning the analysis again. So we'll leave that as one and we'll just make a mental note of how to do that later on. And let's click OK. Now another section that we also need to consider in cracking is this lab sections. Slabs. Even though their post tension, most probably they are going to be cracked in the ultimate load case situation. For that purpose, I always reduce the stiffness is of the slabs even without willing to look at the analysis. The way that we could reduce our Stephanus's in e-Types is through the bending moments M11, M2, and M1 two. Now that is because our slabs or shell elements, which band like a plate on the weak axis and an E tabs based on the sign convention. If you actually want to reduce the stiffness for a slab, just reduced the M11 into M22. So let's go ahead and input our 40% from the Australian Code. Twenty-five percent if you're using the American code. And that would reduce our bending moments for the plate action just out of plane. Now be careful not to reduce your F11, F22, or F12, because these are the in-plane actions of the slabs, which is your diaphragm stiffness. And in diaphragm, you gotta be careful if it actually cracked. It could reduce it from here. If it doesn't crack, don't touch it. Let's click. Okay. Okay. Okay. Thanks it as for reminding me, Let's go ahead and save the work. Now one last element that we need to look at, reducing the stiffness, which is our wall sections. So let's open our war section. And similarly like slabs, if we go to modify our modifiers for the slab. Now if we reduce the m1, n1, and 2212, we're reducing the out of plane bending of the wall. But we know very well that was don't bend out of plane. They actually take forces in-plane. So to modify that, we actually going to modify the most important one is F12. F12 is according to CSI, torsional shear component of your in-plane forces. So if you actually reduce that, it reduces your work capacity to take anymore in-plane loads. So it's not a direct M11 and M22, like what we have for out of plane. It's actually the shear modifier that we reduce four walls. And that way it reduces your stiffness for the wall to take anymore load or to deflect more through implant action. So let's say if our walls cracked. And when we look at our stiffness factors, we found out that we basically only have 10% compression load on the wall. So it's going to be about 30% of our gross section. So that happens, you just gonna input a 30% in your F12. And if you modify F11 and F22, they wouldn't make much difference. Give it a try yourself if you want to prove me wrong. But for the cracked walls stiffness, F12 is where we always manipulating the stiffness of the implant action for walls. For now, we don't know if our words are going to be cracking or not, so we should leave that as one. And we'll touch base on that later on when we start looking at the results of the analysis. Let's click OK and save our model. And see you in the next lecture. 8. Drawing Columns: It's about time we start growing in our model. Now, as a good practice, you always want to start with modelling your columns and your world's first before you start growing in your mean linear slabs. And the reason that is, is because your columns are what makes the buildings tend. If you start spending too much time in modelling the slabs and you've got the columns at the wrong locations. It starts to be a little bit more complex later on in the model. So that's a good workflow there. Let's start with drawing our columns first. So you go to dro beam or column, and you could click on a quick grow option. But also notice that this icon is available for you here on the Draw toolbar on the left-hand side, which I use it most of the time. So let's click on Quick grew columns. Now you'll notice a box is going to pop up, which asks you, what's the probability that you're using? So we're gonna use our C1 column property. Now the second thing is your moment release. If you're growing secondary beam that are pinned at the ends, you obviously need to go for the pinned option. So when you draw your element, it actually is drawn, is banned and not continuous. So if I close that and just quickly look at my 3D model, if I go to this, which is very, very powerful tool that you should keep always an ion, that is your view settings. So if I go to my view settings and quickly go to the Object assignments and switch on my frame releases. And click OK. I can see that my column was drone has been from the top and the bottom. Now if I draw the same column again, but instead of growing a pinned column, I'm actually gonna draw this as a continuous column. So let's column here. We'll see that our column is drawn and it's not pinned. It's actually fixed top and bottom. Now, when the upended column and when you leave them as continuous, that's a judgment that you've got to make yourself. But for me, if the column is cast together with the slab and you've got reinforcement going through the slab, you have that continuity. The only situation where it might be pinned is when it's a perfect pin where you have literally only shear connection. And that doesn't exist in real life. Because we know that just reinforcement in concrete is much easier to construct them, to construct a perfect shoe connections. So 99.9% of the time you are going to be dealing with continuous elements and they're not going to be a real pinned columns. Now let's look at another functions in the growing of the column. We've got our angles. So if we've got a 45-degree column, guess what's going to happen? It's going to be rotated 45-degree. And now that's the offset. In case if I have a column that is offset, lets say a meter to the x direction. If I select my grid. It's offset one meter. And if I save it to the y, 2.5 meters and I draw it again, that's where it is. Now. That is handy in the case where you have columns being offset from the grids, which occasionally happens. Also this is, there is this cardinal point which is the insert, insertion point of view column. Most of the time it's your middle center point of the column. But for some reason if you want to import it from the bottom center, you could also do that as well. So let's have a look at that. So if I draw it to the bottom center, a gets drawn off grid. But I want you to notice, whereas the insertion point, so we cannot see then the nodes here. Let's go and switch on our display options. And let's not make our joints invisible to joints and order the same thing in finite element. Let's click okay. And we can start to see that our joints for the column is actually not on the grid. Or joint is here. Even though withdrew it in here. That's another way of setting it. If it's aligned on the grid, while it's only offset by the size of the column. That's one way you could draw with it. Another way you could draw it is you could just always stick to using middle center. And he could use the offsets functions to get exactly the same results. So if this is a 450, if I draw minus 225, I'll probably get the come exactly in the same place which I did. But you can't see obviously because they are now overlapping. Now another tip right there, if you want to see what's overlapping here, press Control and right-click. And it shows you what are the elements there. So we have joined there and we have a column there. It didn't actually draw the column twice because there's already a column there. But for some reason if you think there's something that might be overlapping, that's a quick tip to know what's there. Now let's go back to our drawing tool. Three sets of that, back to our default. And let's delete all of these columns that we have drawn. So to exit the draw command, I press on escape 102 times. So I'm gonna select all of these columns and I'm just gonna delete them. They go. Now also one important growing tool that we're gonna be using quite often is this, which is flaws are you actually work into. And in this case, since our modelling the columns and I know for a fact that they are the same all the way down from the ground to the roof. I don't need to model them for each floor. So what I could do is I could model it all stories. And basically what that does is if I go ahead and draw one column somewhere looking at my 3D, but I'm going to draw it on my 2D. And voila, it created it for all the floors in my model because I'm modelling to all stories. Now similarly, if I click escape and I select this column. And I press delete. Look what happen. It deleted everything in my 3D because again, I'm working to all stories. So that's very, very powerful tool. But be careful when you modelling something that's only on one floor. If you have all stories switched on, what you're doing is going to be done for all other stories in the building. Another smart function is similar stories. For example, if you've got a few stories that are very typical, Except for example, could be the transfer floor that's not typical. Could be a roof floor that's not typical. Could be an intermediate flow that's not typical. But generally, if you're doing change, that effects a lot of the similar flows, which is most of the time for your plates, for your slabs. You might want to be looking at using similar stories in your modeling. Now let's jump back to our column modelling and we're gonna do it to all stories because our columns are all the same for all stories. That's good to our current functions. And this time we're going to be drawing them Now you could draw them one by one. Or it could, for a fact, to select all of your grids and that you can see it's going to grow it to all grid intersections. Now what we don't want is we don't want these core grids to pick up column. So I'm going to click Control Z. J works in IE tabs and it saves a lot of lives. And what am I going to do is I can go to actually view. And I could go to set grid system visibility. Or there is also a faster way to do it, which is right-click and go to set grid system visibility. And what I'm gonna do here is I'm going to actually select my two cold grids. I'm gonna put them there, which is available, but it's not visible when I click apply to all windows. So it does it on my 2D and 3D and then click OK. Now microgrids are gone, so I don't need to use them when I'm drawing. So I'm just gonna go to draw columns again. This time, I'm going to hover and select from the top left corner to the bottom right corner all of my grades. So I've got all of my columns in. Now one thing that I forgot is that I don't actually have a column here because I have my code. So I can go back and select that. And notice that in 3D it selected all the floors because I'm still working to all stories and I'm just gonna press delete. Now if my 3D view refreshes, that column's gone. If I rotate my 3D view, I don't have it there. Now we've got in our columns and you'll notice that they are automatically pinned at the bottom. If you want to see if you're using the correct section. You could also go up here. And there is this extrude view toggle, which shows you the real sections of use of fuel structure. So make sure you're in the 3D. First the toggle of 3D view. And if you zoom in, yep, that's the square columns that we're looking for. Let's save our work. And see you in the next lecture. 9. Drawing Walls: Now that we've got our columns and let's start growing walls, we could go to dro, draw floor a wall objects. And you will see that we could either draw a floor, a rectangular floor. The difference between these two is, as you could see, you could add as many points as you can for the first one, but the second one, you only grow using two corner points. The third one is quick grow. And you could only use that on plan or an elevation. And you could draw wall openings. So notice that we don't have the option to row worlds on plan or Quick Draw walls on plan available because our active window is actually the 3D view. So if you want to grow it on plan, we're going to have to exit this first. Make sure that we select our window on pliant. And if we go back to grow wall objects, we'll see that we have the option to grow walls or quick grow walls on the plan. So let's go with that. And also as he could notice, same with the columns. We have the shortcut to grow them over here on the left-hand side. Let's go with draw walls. And similar to what we had with the columns, we have a menu that comes up and asks us what is the property that we are drawing? So walls can basically be a peer or a spandrel. Peer is a shell element that basically goes from floor to floor. And it only takes compression and shear in the strong access predominantly spandrel On the other hand, is also on elevation, but it doesn't go down all the way to the ground. So it's an element that essentially just takes bending and shear moment between two peers. Now, what we're growing right now is peer elements. So going to leave it as Pierre. And we're going to select our wall property that we defined earlier, which is the 200 fc dash 40, gonna cancel the saving for now. And let's select that. Similar to what we've had with the columns. We can offer our walls in elevation to that is in the z direction, but we don't really use that function. Do you want to create or to pure spandrel IDs or leave that for now. And we could draw a straight line. We could draw an arc walls, we could draw a multilinear, a busier or a spline. Let's just keep it simple and just go with the straight line. There's also something called a growing controlled type, which is very handy for defining the length or the angle of your wall. So let's say for example, if I'm growing a wall that's three meter, we could select this. And we could choose that. The length is three meter. And if I click this start point, it only fixes the wall length to three meter in any direction that I'm going to. Now, let's go back to that option. And let's just leave that as none. And we'll see that if we start just drawing simple wall from here to here. Let's say it's a five meter wall. You notice it's outside of migrate. Let's keep it on the grid and keep it to five meter. To exit the command, You can just right-click. She didn't want to continue growing in a chain. And totally exit the growing command, you just click escape. Now you'll notice on my 3D, the wall is there. That's a really simple design situation. Let's delete that wall and look at what we're having on this project. Now, one of the ways that we could draw these walls fairly quickly is an option called a wall stack. So if you go to dro draw wall stacks, you can see that you could automatically generate few different core wall layouts fairly easily and straightforward. So the wall we're looking at is this one, which is this type over here. You could input your call height, the length, how many cores you have. And is it a uniform width for the very end, the thicknesses of your walls? And you could even input the door heights and automatically generates all of that for you, which is very powerful. But before we do that, let's go back and make sure that our grids for the course are switched on so he can snap to them when we start modeling our walls. Let's start growing our first chor. Let's define the first core, which is this one over here. Let's click the two core option, the multi-cell core option. And I'm gonna drag this and make it wider so I can see what's happening over here. My core height, which is this actually, it's actually width, not hide is 3.1 meter. But notice that this hype is excluding the thickness of the end walls, if you can see over here. So we've got 3.1 meters center to center, but we've got our walls as 200 thick. So we gotta take up to a 100 from the 3.1. So that leaves us with 2.9 meter are called width, which is actually the length of each core, is also excluding that 200 mill because it's taken from the internal dimensions. So this 2.7 will become 2.5. And this second core, which is 5.3, becomes 5.1. We've got two cores for that core wall. And yes, this is a uniform width. The thicknesses are all 200, which we are going to verify when we do our design later on. Our opening height is 2.4 meter, so that opening hide is the door height. And for this project it's taken as 2.4 meters. And this opening width is taken as only one meter. For both the left and the stairs door. Let's click OK. And let's see how that comes up. So as you can see, it snaps to the blue points that is showing you, and it snaps to the grids basically. So you could just move your mouse and started snapping the points, the grid. Now that, that's very beneficial, that we have those grids defined initially for our two core. So he could snap to very quickly. But that's not the only benefit of the grids as you can see throughout the project, there's other benefits that will start coming up as well. Make sure to choose a correct story heights. So we're going from the highest story all the way to the lowest story. And let's snap it back and click OK. Now I'm going to right-click to exit the drawing command and look at the 3D view. And you'll see that my core wall was added in with the openings at each flow. If you actually want to see that in more detail as switch back to my plan view of any story. And you'll notice that I've got one over here where the openings are. And I could go to Elevation view and E tabs to look at this elevation. That's my core to one. Let's open that elevation. We can see here that our wall was created, the door openings were created and it was automatically pinned at the base. That's very fast way to grow your course specially, you get the openings in. 10. Drawing Walls Part 2: Now let's add our second core over here. So we're gonna go to drawing walls tax again, selecting our multicore layout. This time, we're actually going to have three cores. Our core HIV is like what we've worked previously, 2.9. And our core width is simply The reason that is is again because it's this 2.6 minus 100.5 of which is half the wall thickness here and 100.5 of the wall thickness here. Let's click OK. And it's a uniform width less input. Our wall thicknesses, again. We have got the height of 2.4. What's our dough width? Again? It's one meter, one meter, and one meter. Now, we've got our openings on this wall stack to the south, but actually in our model is to the north. So we've got a mirror this about our axis. Three. So let's click yes. And you can see now we've got our Corps opening in the correct direction. Let's click OK. Make sure the extent for the full higher than building. And we're going to input it to our grids that we've defined earlier. Right-click presses k. Let's look at 3D. There we go. We've got our two cores. We've got our openings inside. One last thing that we need to check is the sections of those walls. So to do that, you can select any of these walls and you can right-click on it. And that takes you to an information page called Wall information, which is where you can see anything that's assigned to that analysis element. So if you look at the geometry, he can see the type of this wall. You could see the joints of this wall would show it's connected to. And if you go to assignments, you can see if that's an opening. What section is assigned to this wall, if it has any modifiers, and so on and so on, would be covering few of these items as we're going through the analysis. And yet, obviously also if you have any loads assigned to that element, what's really important to us right now is to know what section is assigned to this wall. So we can see that this is a wall Section eight, which we didn't really define. Just ETags created it because we were using that wall stack modelling option. But we want to give it the correct wall section that we're using. So let's go on. Go on and click on our set display options. Let's go to object, assignments. Assignments, and switch on our sections. Now we can start seeing what section was assigned to each of these walls. What we could do in this case is we could go to all story selection and we select them one by one. But that might take you a long time, since we're only using one walled section right now, and we only have those wall elements define. There's a quick way to select them. We could go to Select, Select. Lets go by object type. Let's select all of our walls. Click select. Now we have all those walls selected. And you can see here we've got a 441 shells select. And we could go to Assign shell. We could assign wall section to them, which is our 200 dash one FCF 40 that we defined and we click apply. And you'll notice that all of them now have the section that we defined earlier. Let's click save. And to hide this section, let's go back to our display options, object assignments, and switched those sections are, let's click this one to reset the views. And there we go. See you in the next lecture. 11. Drawing Walls Part 3: Now if you're thinking that modelling core walls in e-Types is just as simple as what it looked like. Annex too good to be true. You're right because it is too good to be true. Most of the times. What you model is what is repetitive throughout most of the floors. And you'll start editing and modifying the cores as required to suit the project that you're working on. For this project, let's assume that this lift over here has another door opening to the South on the ground floor. And let's assume that this test has another exit over here. So there's another door opening and the edge over here. How could we add that in Etypes? And usually modifying what you have is going to take a bit of time actually faster than drawing the typical ones. Let's increase our e-Types and start seeing how to do that. Let's add another window and make sure that all of our grids are switched on. Let's add this opening over here first. To do that, we're going to have to work with the elevation of this wall and model the opening in our elevation. And that's when you start to see the benefits of using these grids for each cobol and eat up. Let's go to this elevation first. Make sure that you're active in this window. And click elevation. This is our core one, elevation one. Let's click Apply and close and we'll see that we have our elevation of this core wall over here. The sign convention for Etypes for elevations can be a little bit confusing. If you've got an elevation along x, e-types got it looking towards y. But if you cut it along y, e times cut it looking towards negative x. So since we are cutting the elevation here and looking that way, we can be sure that if we select this one, it's the one on the right hand side. And you can see that it's selected over here. Now it's important to know that because the way that we're going to add our opening is through dividing our shells and copying, copying the points that we have here. Let's start doing that. So let's select this joint. And let's go to Edit, replicate to make a copy of that joint. A shortcut that I like to use for this is control are, which is very fast to just get it started. Now let's assume that this opening starts after 0.85 in the x direction and it's one meter wide. So we'll copy the first in the x direction of 0.85. Make sure we select the joint click apply. And let's copy the other point of the opening, which is one meter. And let's click Apply. Now we've got the two locations of the opening in the x-direction, but we didn't know how high is this opening. Now, if you recall, I'm gonna go to that view. I'm gonna close my replicate, and I'm gonna open my 3D view. If you remember, when we model our Of course tags, we've defined these heights to be 2.4 meter. And what it did is it actually divided all of the worlds. The 2.4 meter height. This gives you a better meshing results later on. But it also is beneficial because we know that this here is 2.4 meter and this is the full floor to floor height of 3.8 meter that we defined. Let's assume that this opening is slightly bigger than that. Let's assume this opening is three meter for some reason. How could we get the level of debt? We could get it through something called reference plane. So let's go to draw reference plane. Russians plane is basically temporary, plain that he could draw and snap too. But it's not really a story. So let's say this is three meter. And we are drawing it to the core two grids. If you select any point here, it's going to draw the grid at three meter above that level. So I'm going to select this one and you'll notice that it got grown over here. That's where it is. Now what am I gonna do is I'm going to select this shell and I'm going to start dividing. So first, I'm going to divide it through an option called divide shells. If you go to edit, edit shells and divide shells. This option is very beneficial when you are cutting wall elements because they are shells. One cutting slab elements, which are also shells. So you cut it at joints. But that's only applicable for slabs which we are going to be using later on. You can cut it into smaller pieces or you could divide it at intersections with other elements in the model. In this case, we're gonna cut it at the intersection with my two joints over here. I'm gonna select, cut it with the joint option selected. Click apply. And we'll see that it cut our shell at the locations where I selected the join. Let's do the same for this shell over here. And let's click Apply. Now we still haven't got the division with the reference plane. So what am I gonna do here is select this one, and I'm actually gonna select two, divide it with the visible grids and click apply. You'll see that it divided it to the location of this reference plane, which is three meter above the base level. And all what I have to do right now is just select these shells which are not there because it's an opening and press Delete. And there you go. I have my three meter by one meter door opening, the bottom of that left. Similarly, you can also see it in 3D. Now similarly, if, if I'm working with a stairs over here that is having an opening of the ground floor. Let's start looking at that elevation so we can look to core to elevation c. Let's make sure that we're active in this view. Click on innovation or to elevation c and click apply. You'll notice that we have two walls here is because these two align perfectly on the same line. So they are visible on the same elevation. But I'm only work into this course, so I wouldn't bother about the second one. Now if you notice also that if I select this showing, it's this joint over here because like what I just mentioned, e-Types cuts the section and looks in that direction. Now, let's start adding our door opening here. But for this door, we're just going to assume it's only the 2.4 meter that we had here. So I need to copy this point. I'm going to use the shortcut Copy Control R. And that is going to be copied in the negative y direction. So I'm going to put my x to 0. I'm gonna put my negative y to be a one-meter. Thank click Apply. And I'm going to close this. I need to divide the shells like we did before. We could actually, let's save that. We could actually switch on that division through clicking on my toolbar and switching on my editing toolbar. And in the editing toolbar you'll notice there is the divide Shell option over here that can save you some time. Let's click the shell, clicked joint, divide the shells with the intersection of joints. And there we go. We have that shell we deleted, we created the opening on the ground floor. Let's look at my 3D. And he better. We've got our opening in the ground floor there. Now, let's save our model. One last trick that I'm going to share with you about editing walls is modifying some of the openings, locations, or sizes. Now if you look at this tears, it doesn't make sense that our state is opening is here. But if you recall from drawing our wall stacks, we didn't really have an option. Put the location of this opening because by default it put it to be central. One thing that is not realistic in this project. So let's go ahead and edit that. Now I'm gonna switch back to my plan view just so I can see the grids. And that is my grid one on the second core wall. So I'm going to switch to that view with my elevation. That's my core to grit, grit one. And click Apply. Now let's fix those tears locations because that just doesn't look right, does it? So what we're going to have, what we're gonna do is we're basically going to select all of these shells. Let's switch on to old stories and start selecting these shells over here. Now, you notice that it didn't select all of them when I was selecting the ground floor because these shells are not the same size as these ones, because the ground floor float flow high was much higher. So you have a different geometry for these shells than these ones. So they're not exactly the same and that's why e-Types doesn't select them, so you gotta be careful about that. Now we've selected all of them. What we're gonna do is we're going to press Delete. Now we're going to move all of these openings to hear so well we have to do is we have to move the joints. Now I find that to be the much easier way to go about it. If you select these joints. And let's select the joints as well. And what we're gonna do is we're gonna go to Edit. Move for you could just use the shortcut Control M, which I do most of the time. If you go to Edit, move joints. And basically we want to move this from here to here. So our opening size stays the same, but these ones become bigger. There's a fast way to do it, which is just picking two points. Say you can move it from here to here. Automatically measures how much is that distance. And if I click Apply, it moved the opening Emmett extended that shell for us and did it for all the floors. We then have to divide the shells within, have to move the shells just by manipulating the joints that form up the shells can start to edit and modify it Geometry much, much faster. And if we look at our 3D, now, our stares makes more sense that the exit is here in the middle of the stairs. Let's save our model and see you in the next lecture. 12. Drawing Slabs: Now that we've got our walls in, one of the last things that we need to add in our model are or slaps. So let's do that. Let's go to our plan view. Starts with the story number nine. Make sure that all of our grids are switched on. Actually, we don't need the call grit. And let's do that for all when this. Now, if we look at our project, we'll see that our group, our slab is fairly simple outline because it's rectangular, but it's offset 2.2 meter from our joints to the column. So let's see how we can draw that. Like what we were drawing on for the walls. You can go to draw floor. And you could draw the floor using the points, or you could just draw using two corners, or you could use a quick draw. So what role does is that it draws it based on the grids. As you can see, it's highlighting in blue. The other drew option. If I go to rectangular, what you gotta do is you've got to select this one. You get a select, press, drag it all the way to where you want it to be. And a lot of that and working with all stories on, so it edited for all stories. I'm gonna go ahead and press Control Z. The other ways also, you have the growth shortcuts here on the left side. So if you use the same command to draw rectangular sections, but just give it a dimension, say 15 meters in x and 15 meters and y, any just input 1. If that point is the center and it generated based on these dimensions. The other option which is growing using as many points as you want. Basically what you're doing is you're selecting a point by point by point by point until you go back and you close it or you press Enter. Now, I didn't really snap to the correct points over there. If you've noticed, since we having a rectangular grid, I'm not going to use that command. Might be helpful if you have protrusions out of your slab going in and out. But not in this case. I'm just going to go with a simple one. Draw rectangular miniature. I'm selecting the correct slab Properties. And I'm going to click at that point, drag it all the way to this point over here. And I drew it on all the floors, including the base, is not correct. So let's switch to one story. Select that one and later. Now how the create those offsets for the 200 slabs. One way you could do that, just make sure it is switching back to all stories. So you're editing all the flows again. You can select your elements and it could go to this tool which is reshape your object. So E could also put that to a fixed length. Let's say we're gonna do 2.2 meters. Let's click our slab and you notice that it gives you points that you can drag around your around your slab. Let's drag that one up. And he noticed automatically snaps up to my 2.2 meter that I've defined. So doesn't matter how far I go, it's fixed to this 2.2 meters. So I'm gonna do that and automatically fixed my two meter, 2.2 meters. Same in that direction. Same in that direction. And same in that direction. Now there you go. I've got my slabs. They extended out from the columns by 2.2 meters, like what I've had this project. Now the only problem is these labs now are running through my stairs. One way that he could fix this is through drawing an opening, which she could do using also the same command. But this time I'm going to choose an opening. And I could start adding some openings here and here. I could add some openings here. And similarly do the same for the other core walls. The only problem with doing the, doing it that way is if you select your slab is that you don't have an edge around the core walls. And I prefer to have the shells broken around the core walls because I like to release the connection to the core walls in case if the core wall is a precast or institute. And I don't really want to rely on that connection to take moments into the core wall on the weak axis. So the way that you could do that is through assigning edge releases, which we're gonna go through later on. But for now let's just break up our shells correctly around the core walls and not rely on these openings. So let's select our slabs. Let's select this point. And if you remember from the wall editing lecture, if we go to divide shells, we could divide this shell element at the intersection with this point cyclical KX. Nothing happen. Well, because that only works for walls and because this point is not really on the edge of the slab, this is an interior point. So the other command that we're going to use here is cooky cut the flows at the selected joint with an angle. So if you put it at a 0 degrees, it cuts it horizontally. If you select this shell disjoint and he put it to 90 degrees, it cuts it vertically. And similarly, I'm going to keep going around and cutting my shells around my core walls. Now I have this shell, I have this one, this one, this one, and this one. So one thing I could do is I could actually merge those shells. So if I select this one and this one and click merge, it shows you how it's gonna look like which properties it's going to be taking from. So it's going to be using this FH held property to the new shell that's forming all of these together. And then click OK. And you can see that now it's one big part of it has edges around my core. Similarly also, I could go ahead and join this one with this one. Let's merge the, merge them. Click OK. Let's merge this one, this one, and click okay. Now I have one big shell here, one big shell here. But the advantage I have is I could select the edge of this shell. And I could edit the properties of that to release any bending moment into the core wall. So that will check that I haven't doubled my slabs because I kept cutting in and it might get doubled with the openings. Let's go to our set display options. Switch off our openings and click apply. And we'll see that we've actually got doubling up of slabs that were not shown because the openings we're overriding them. Let's just select these ones and delete them. And switchback our openings. Now we've got our slabs in place. We've broken them around our core walls and our stairs, and we are ready to move on. Let's save our model and see you in the next lecture. 13. Drawing Beams: One last item that we need to draw in our model is our beams. But if you notice that this building doesn't actually have any concrete beams because it's a flat plate. But while we need to do is we need to actually define some beam elements around the perimeter of the building to assign the super imposed dead loads of the facade of the building to them. Because an e tabs you cannot actually assign those line loads to the shell elements. You gotta do it manually through using some line elements that have no stiffness and no properties at all. So the way we can do that is we could go to grow and we could draw our beams. This is basically working using two points. We select the first and the second. There is an option to row them quickly. And usually that works using your grids. So if you've got an RC structure with main beams, that might be a very helpful tool to start growing your beams quickly. And you can choose them to be continuous or been based on primary or secondary beams and the actual conditions that you have. But in this case, we cannot really snap to the perimeter of the building because we haven't defined any grids there. Instead, what am I gonna do is draw the beams using these two points option, which again you have it on the left-hand side here, which is your drawing toolbar. So let's go ahead and draw our beams. Now, the section type is always a frame property. Since I don't want it to have any stiffness or any mass or anything to do with the analysis other than just taking the loads, i'm gonna go to non-property. My moment releases wouldn't make a difference in this case. And I'm drawing a straight line. So let's start throwing them around the perimeter of the building. And when I'm done up, press right-click and escape. You'll notice that it didn't draw them to the base this time because our snapping to the corner points of the slabs which are not there on the ground. So ETags figure that that's not going to be done there. Now you can see that you have your slabs here and you have your beams here. Because if I click on the edge, selected them, and it says here you've selected nine frames. One way to see them as well is if you could go to select and deselect by the object type. Actually, if you select what properties, a frame section, and you select your non sections, click Select, and go to your 3D view. Right-click and show selected objects only. You'll actually see all of them here, but they're just grey in color, so they're a little bit difficult to see, but they're definitely there. Now will start applying some loads in our next lecture and there'll be very handy. See you then. 14. Meshing and Releases: Let's look at some of our meshing options to make sure that we're getting the best results out of our e-Types model. Now E taboo is very powerful in its auto machine functions, but you gotta make sure that they are activated. For slabs there usually under analyze and automatic mesh settings for floors. Notice that by default or mesh size 1.25 meters. Now I like to keep it to one meter and see if I need to reduce the mesh size later on in the future. The way that you could see that is if you run the analysis with say, one meter mesh and you note the results of, for example, one of the columns. And in the next run of the model, you reduce the mesh size to say 0.75 meter instead of one. And you see what's the difference that had on the column reactions, for example, or the displacement of the building. Now, if the difference is, let's say, less than 5% of change, then probably reducing your mesh size is increasing your computation time a lot, but not giving you the maximum benefits. Starting with a one meter is usually good for slabs and you can start reducing that if you see that there is non-convergence in your mesh. Let's click OK. And now four walls, by default, ETags doesn't mesh walls. Let's switch on everything. Back on from here, let's click, right-click and show all objects. So by default, e-Types doesn't actually mesh walls. Where you gotta do is you get a select all of your walls. Select them and you go, go to Assign shell. Let's assign our wall auto mesh options. And let's put that to auto rectangular mesh because by default, if you see there is no meshing. So let's put that to auto rectangular mesh and click OK. Now how big is that mesh is also under analyze auto rectangular mesh, four walls. I like to match that with the slabs. I'll leave that as one output that is one metre. Now one last thing that I need to look at is meshing those none beam elements that have had at the edge of the building. So to select them. Okay, go to Select Properties and I'm going to start selecting my frame sections of none. After I have them selected, I'm gonna go to Assign frame and frame floor meshing options because these are actually non stiffness, no property at all sorts of analysis elements that creates problems in your model if they are not taken correctly through the meshing. So I'm going to match the meshing of these with the meshing of my floors so they don't create problems in my analysis model. I'll click apply, and I'll click okay. So now matched our walls of floors and our beams. And we need to do one last thing, which is having looked at those slab releases. To do that, I'm going to switch off my wall and my openings. And click apply and click OK. What am I gonna do here is select all of these edges. Now if you notice here it's starting to give me wrong selections because I don't need all this. I only want it up to the edge of the wall. So I am going to have to break that one up again at 0 degree. And I'm going to have to break that one up, 0 degree. I'm going to break that one up here. That one was okay. That one was okay. That's okay. Yep. So let's select all of these edges. By clicking just at the edge of the slab out. We found the problem here. Let's break that one at a 90-degree. Alright, let's go around the slab edges and select them one by one. And if you know this that I'm working with all stories. So I've selected a total of 72 edges. That's good to Assign shell, what we call an edge release. So what that does is it releases some properties at the edges of those shells. So if I go to ads releases and selected shell object and choose a bending moment, twisting. I don't like to put it to 0 just because sometimes that create problems in the analysis model. I just like to put it at a very small value, let's say one that's very, very small value. The shell wouldn't be taking a moment, but it's just not 0. So it doesn't create problems in your stiffness analysis. And let's click ply. So what does it releases the moment about that edge of the shell. But it's still transfers yo shear force and your diaphragm forces. So let's click apply. And you notice that it tells you how you've got the releases on these edges. Now with done with assigning our leases and meshing options. And see you in the next lecture. 15. Model Check and Verification: Now that we have our structured defined in the model, it's time to start checking that everything is in the correct place. Let's go to analyse, check model, and make sure that we check all including the join story assignment. And let's click OK. Now if you notice here e tab degenerating the analysis mesh in the background. And it's trying to check for any problems in solving the mesh. And what it detected that there's no errors and no warnings so far. But it didn't run any analysis tests, just check of geometry and the connections of dynodes. That's a good sign that we did a good model that doesn't have any errors in the analysis. Now what we need to do is just by visual inspection, we need to look at the base of the model and make sure that all of our elements have adequate support. Because not having supported the Bayes is one of the biggest reasons that you run into problems with the steps. One way to do it is also going to the lowest floor of the building. And you can see here that we could see our support. And they are green in color and they have a pin support. Looks like all our columns have support. That's a good sign. In cases where you might find there is a column and he didn't have a support. That would usually be the case if you copy the column. But e-Types doesn't copy the support if you copy the column by default. So if I select it, for example, let's say this column and I copy it using the keyboard shortcut Control armor. And let's copy just three meter to the x-direction. And click OK. Now if you look at 3D, that column was copied, but it didn't have support. So that's one of the reasons that you might be running into troubles with your e-Types model. If you copy columns, any forget science support before you run the analysis. So just keep that in mind. Now we don't need that column. So I'm just gonna go ahead and delete it. Now also, I started seeing something with my model here because I was working to all floors by openings were added to the base. Don't really have those openings in the base. Now our openings are switched off. That's why we cannot see them in the bass. What I'm going to do is I'm going to click on set display options. Switch on opening Lego k. Then I can see them here. And they know that I don't have them. So I'm just going to select, let's take the model, just gonna select them and press Delete. Now that's cleaned up and looks better. So let's run our first analysis just to make sure that everything looks right in our e-Types model selected go to analyze. But first before we run the analysis, we are gonna go and select what is analysis type that we're running. So in the tabs there's three different solvers and they differ in their accuracy. So multi-threaded server is the fastest one, but a miss on some errors or it might not tell you the model has instability or buckling problems and things like that. Now for the first run of the model, you want to run it with multi-threaded just to make sure that everything is working fine. And then when everything looks okay. And then you could switch to a longer, more detailed analysis using the standard solver that is going to detect any instabilities or buckling in your columns and so on and so forth. But if you start with the complex analysis in the first place and you don't know if the model is actually functioning properly or no, you might end up spending a few minutes just waiting for the analysis to run and it's not converging. So it might take a very long time and it might never converge so far suggests just starting with a multithreaded solver first. And then you could click either on analyze, run analysis, or you could press on this Play button over here. Now our analysis done and we're just gonna do a visual inspection of the building. Looks like everything is in place. And let's switch to flow plan. And actually check the deflections of the floor to see if everything is as to what you'd expect to know. To do that you could go to the display deformed shape. And you also have this deformed shape function over here. So I'm gonna switch on my bed load case and well leave e-Types to scale reflections. But I won't eat absolute row the contours for me, for the reflections in the z direction, which is the vertical direction. And I'm going to click okay. Now you can see I have a better for big deflections on this one. Next, we could start looking at our frequency of the building. So we go again to display the form shape. But this time we're going to switch onto mode. Now we didn't define any modal analysis yet. But by default, all e-Types model comes with Eigen analysis. So it already ran it in the background when I clicked Run because I didn't uncheck it. So let's click OK and see what's our period for this building? Looks like our period is 1.8 seconds. And if we go to the topmost story of the building and switch the deflections here. Also to the Eigenmode. Without growing any contours. And you could start your simulation over here just to see how the building reflecting. So let's click start. Over here. Has this weird town for animation. It's almost like a sarcastic laughter switching off. So as we could expect, in our frequency of the building, it's torsional because we have our core is offset from the center of stiffness and the center of geometry. So that actually sounds about right. Now one quick check that you would expect the frequency of the building to be, is roughly about 0.1 times every floor that you have. So in this case, we've got nine floors times 0.1. You'd expect the frequency of around 0.9 seconds to maybe 1 second if the building is quite flexible. But in this case we are getting 1.82 fundamental period, which is quite long and indicates that this building is actually quite flexible. So we might be running into problems when we start looking at our lateral load analysis. And we might need to add a shear wall here, something to resist this torsional behavior of this building. But for now, we've run out checks, looks logical. And what we could do. What we could do is we could stop everything through quickly on this to show back the undeformed geometry. Go here, click on it again. What we wanna do now is we don't want to unlock the model, which is going to delete the analysis that we just ran. And we're going to jump back to analyze. But this time we're going to switch on our standard solver for e-Types. See if there's any instabilities in the building. So let's run, analyze and see what's going to happen. So our standard solver analysis just finished. And let's see what happened in that analysis. Let's go to analyse last analysis. Run log to see what happened in that analysis. And if we can see over here, we start from the top. It took about 10.5 minutes long, given that the other analysis only took less than, say, thirty-seconds. What do you want to be looking for is basically that's the first one. That is the stability check. So I gave you an eigenvalue that could range from 0, negative one, negative two, negative three. So basically that means when there is a negative eigenvalue more than 0, that means that you have one support that's not actually defined properly, like you have a column and it wasn't defined with a pin support at the base. So the structure is unstable. Or you might have a column section that is actually too small. It buckles. That's why it's not stable as well. Another thing that might be here in your model, if you have a lot of problems in your modelling and medium, actually draw everything correctly to the nodes. If you had a lot of offsets and things like that, you might start to have what we call digit loss or error. So that value could be anything from negative five all the way up to negative 12 or something. So what you want to have is probably negative five to negative seven or negative eight. It's still okay. But if you start to have a digital lost more than eight into ten is probably you are getting some errors in your load transmission somewhere in the building. If you're getting more than ten, definitely there is a load path problem and there is an error in solving the stiffness modal by E-types, which means something is not connected properly and the building is not functioning correctly, or at least e-Types is warning you bought it. If you feel confident in the results, then just drop these error values. If we go down in our analysis log, we could also see the periods of the building. So we can see that the first mode was 1.8 seconds is 1.4, and the third is about 0.85. So now we're comfortable that there is no problems in the way that we modeled the building. And we feel safe to start spending more time into defining our other load cases that includes live loads, wind loads, earthquake loads, notional loads if you and apply them as well on the building. And even assigning these loads to the building because that can take a little bit of time. And if you start doing all of that without having the confidence that your model is actually just running and working. There could be a nightmare measuring if you spend the whole of the next two modules in terms of work in your model. But then when you run the model, it doesn't run. So that's why I was preferred to just model in the building first and run it with the self-weight and see if there's any problems to start with there No, because if there is problem from the start, I might as well just not waste my time and try to solve these problems for us. Anyway. I hope that is clear. Now, we are ready to move into the next module and start applying some loads into this building. 16. Gravity Loads: Hello again. So now we're ready to start defining some loads into our building and doing some more detailed design. Let's first unlock or model from the previous analysis to start defining our loads. And let's go ahead and make sure that our analysis from now on is just the multi-threaded solver. To save us that 9.5 minutes of waiting every time we want to run the analysis and check something. Let's click OK. Let's start first by looking at our gravity loads. So we're gonna go to define load patterns. And we can see that by default we have our dead-on live loads are already defined for us. And we don't need to do anything else. But what I like to do is actually add another load case, and I would call that a reduced live load. So I'm going to call that live load. And actually the analysis type, I'm going to change that to reducible live load. And I'm going to click add this new load. Now, if you also want to add some superimposed dead load, instead of just using the self-weight of the building. Then let's go ahead and do that. So we're going to call that super imposed, that load or as d l. And we can put that as super dead and we could add it. Now, I don't usually define superimposed dead load if the building is fairly simple and I'm not planning on carrying out a construction sequence analysis. Superimposed dead load is fairly helpful if you having a complex building with transfer structure. And you want to start running your construction sequence, which we're going to look at in the bone section. Having that superimposed dead load just differentiate the self-weight of the structure alone when it's still going under construction. Then when the finishes are applied at a later period in the building construction. And that affects your creep and shrinkage. And basically the behavior of the building over time it gets, it gives you more realistic deflections. And it gives you more realistic strains in the building, especially for high towers or even super high towers. You want to be differentiating back. Because by the time you finishes are applied in the building, let's say another four to five weeks. The concrete has already reached much higher strength in your building. And it's creep and shrinkage effect is going to be reduced because by the time that the finishes are applied to the building safe 5-6 weeks after the concrete is constructed. By that time, your concrete has already reached its full strength and the load is applied fairly late in the building construction. So that actually reduces the creep effects. And the creep effect in concrete buildings can sometimes W or deflections. Or your axial strains for example. So it's very helpful to separate that superimposed dead load from just the dead load in very specific cases. Also another case we're separating might be helpful is when you having a tanked basement with water pressure. Because if you look at designing your world or your basement slabs in a condition where there is a water pressure. You don't want to take your super impose that loading to account because that is going to help you. So you only relying on the self-weight of the structure without the superimposed dead load. And in this case, it will be good to define a super dead load case as well. But in this case we don't really need to, but I'm just going to use it for the purpose of demonstrating how I'm going to be doing that in case if I needed to. So let's click. Okay. So now we've got our debt super dead, full live and reducible live. So let's click okay. And sat looking into applying those Lawton to or building. So there's a few ways that you could apply these loads. The first one is e, could just apply them manually. So let's say I'm going to select all these slabs which are on my roof level and getting go to Assign shell loads, the uniform load. Let's say for the roof, I have a dead load of around 3K EPA and it's applied in the gravity direction. Now, that is going to be my superimposed dead load. And let's click apply. And you start to see that the load values are showing up in the plan. And then what I need to do next is I'm going to switch to my live load. Since that's a roof and it's not reducible. I'm just going to apply my, say, 1.5 KPI would just assume that this is accessible for some reason. And it's also in the gravity direction. That's click Apply. Now ESEA areas because it didn't select shells before I click Apply. So one quick trick to do that is to go here on the left hand side and select, Get previous selection that selects the last election that you have before you apply the command. So if I do that, it's selected Michelle's back again. And it's always good to have the 3D in places to see which elements you have selected. And in this case it's only the roof shells, which is what I want. So let's click Apply for that by float as well. Now we've got our loads defined manually for these floors. What I'd like to do now is to actually go further down. So if you notice these arrows are to switch between the floors. So now I'm a story eight instead of story nine. Another way of applying the loads fairly quickly is by defining these load sets. So if you go to Shell uniform load sets and let's create a new load set. Let's call this the roof, for example. And for the roof we know that we're gonna have to load cases which are superimposed dead load and not reducible live load or super daddy's three and our live load, these 1.5. So let's click okay. And now we have another load set which is going to be or office. For this load case, we also have a superimposed dead load, but this time we actually have re-used live load. So we can have one super imposed load and three KPI, a reducible lifelong. That's click OK. And let's click okay, so now we have defined our load sets. What we could do is we could select the shells that we're going to apply this to. And we could go to Assign shell load. But this time we gave the uniform load, said that we defined. And we're just going to put an office and click Apply. And now it says that this shells, the shells have office loads applied to them. Now, one benefit of using load sets is if you've had some changes into the future and you can quickly edit all the loads for all of these shells through simply modifying your load set. Instead of going back to each and every shell and editing load by yourself. So it can save you a lot of time in case if you had an error in your model in terms of flawed assignments, but you'd really be getting your lot correct from the first time. But sometimes the finishes could change in the building, for example, and the architect adopted a heavier finishes. But your live load is not likely going to be changed unless the architect changed the design of the building or something. That being said, I still prefer to use load uniform shall loads because I can just apply it once. I don't need to apply that load and change the value and apply again the live load. And that might not seem like a big advantage, but it reduces the chances of the error that you could make in your model. Because you can see straight away what is the load applied for these shells. You don't have to keep inputting the loads for each and every time you apply them. So it minimizes the repetitions that you have to do which got sued chances of making an error in finding the loads pretty much. Now we've applied our load here to only one flaw, which is level eight. We're going to need to apply all of these loads to all of the other floors as well. One quick trick to do that is to actually use a function that we sort of touched on earlier ads called. So let's just undo the loads, but we just defined go to edit. And let's add our stories to define those similar stories. So we go to modify stories. And over here, we want our level eight to be the master story. And we want all the other levels not to be mastered. We want them to be similar to or Level eight. Okay, so now we have defined all of the other floors not to be a master story. Instead, they are similar to level eight. So whatever changes that we do to level eight or any of these similar stories that are similar to level eight is going to affect all of them as long as we are working to the similar stories command here when we are assigning our load. Let's give that a try. So let's click OK. Okay. And this time, and this time we're gonna make sure that we're actually working to the similar stories. So if you notice here, just to check it quickly, if I select one shell, it says there's HER selected. And in 3D you could see it selected all of them except for my roof shell. So my roof was not selected, but all the others were selected because we work in two similar stories. So let's go ahead and select all of these shells. And let's click office. Now one thing I'd like to just keep in mind that sometimes you may have divided some shelves differently on different floors and that results in some of the shots not being exactly similar. So when you select them, it doesn't get selected and all floors. For that reason, I always like to run my eyes over the other floors one-by-one. Make sure that all of my shells have the correct load assignments, which is an office. And now if I select my roof shell, didn't select anything else because it's just a roof. So I'm gonna right-click on it. It's going to check I've got my loads applied for it. So let's go ahead and just leave it like that. One last thing to be mindful of is that we haven't defined our live load reduction values. And by default, ETags uses the American code to calculate the live load reductions. But we work into Australian standards so we get a goat to design live load reduction factors. We gotta make sure that we are working to our Australian Museum and standard. And we're going to apply this to axial load only, which is for the design of columns. And we're not going to reduce the bending moments on the call. Now, if you notice here, for a single soil we're going a minimum of five. And for a multiple storage at a minimum of four. But actually STM standard is to a minimum of 0.5. So we're gonna change that to a minimum of 0.5 and click OK to close this. Now one last load that we still have an applied is the load which is around the perimeter of the building. To do that, we need to select all of our beams are going to take the slowed. So we could go to a select tool, select using properties. It's a frame section. Let's select all of our non-members that we defined in the previous module. And let's go to the 3D. And that's good to assign frame loads, distributed loads. And that's assign superimposed dead load. That is a 2k APA. The force direction is in the gravity, so it's always going to be downwards. And this is a force. Now if you want to vary your force and the beam elements, you could do that here, but we just have a uniform load, so we just click apply. And you'll see in 3D that we got our UDL load applied on our frame elements now. So let's close this window. And we've got our loads, define them, we are ready to go. So see you in the next lecture. 17. Wind Loads: Hello again. Let's now look at defining some wind loads to our structure. But first, before we get started too, that we need to define out diaphragms in the structure. Diaphragms are like the horizontal plates that tie all of your vertical elements together and transfer all of the lateral loads at each flow back to the lateral load resisting system. So say you have the cladding around the building over here. The wind is going to hit the glass clouding first. And then that cladding is tied to the structure at each flow, which is tied to the concrete slab, which acts as a diaphragm to compress all the loads back to our lateral load resisting system, which is these two cores of the building in this case. So how do define those diaphragms? First, we're going to set them up through going to define diaphragms. And you notice E-Types has by default one diaphragm type. Let's use that. But first let's check what properties it has. And we see that there's two types of rigidity for our diaphragms. A could be a rigid diaphragm or it could be a similar rigid diaphragm. Now, the difference is basically if you've got your load at this corner for example, and the load is going all the way to here. A rigid diaphragm assumes that the slab doesn't compress at all because it's infinitely stiff as semi-rigid diaphragm actually takes into account the formation of the slab. And it actually considers the distribution of the load based on that deformations. The advantage of using rigid diaphragm is that you analysis would run much faster because you don't need to consider these deformations into your analysis. And the advantage of semi rigid diaphragm is the correct distribution, for example, between different load resisting systems. If you have cores at different sides of the building and fuels at different sides, taking into account any openings that might be there in the building that my weaken your slab to compress the lows and transferred back, for example. So if we had a very big opening over here, for example, that's a case where I'll actually choose semi rigid diaphragms. So I can take into account the deformations at the slab to take all the lateral loads around this opening back to my course. But for this case, we're gonna stick with rigid because we don't have that big opening in our flow. Let's click OK. And now let's first select our slabs. Let's go to Select Tool, select. And let's like where the object type. We want all of our flows. And click select. And you can see we have all of them selected. Now we're gonna go to Assign shell diaphragms. And we assign the diaphragm D1 that we just edited and click apply. As we can see here on the plan that iframe got assigned, but we couldn't see in 3D. So what we might do is activate the 3D view and go to our set display options and switch on our diaphragms. And click OK. Now we can see that we've got our diaphragm defined for all of our slabs. Let's switch it back off to clear our visual display. Now that we have that, we can start defining our wind loads. So let's go to define load patterns. Now we're going to be going through the definitions of the static when load. And let's call this w one. And let's change that to wind load case. Now you've got the option of manually assigning the loads yourself later on. And if you want to do that, you wouldn't select any atom or to lateral loads. But in this case, we're actually going to use ETags built-in function to calculate the wind loads for us. So we're going to switch on our auto lateral load and we choose the design code that we're designing to. In this case, we're doing it to Australia, New Zealand standards. So we're gonna go ahead with that and click Add New load. Now let's modify this load to see our definitions. First thing is keep in mind that this is static equivalent wind load. And it has limitations as set out in the Australian code. So it's only applicable to buildings that are less than 200 meter high and generally that have higher frequency than 0.2 hertz, which we meet in this building. Now the first parameter that we are going to be defining is our wind direction. So let's click on modify. We can see here our diaphragms. How wide is the building and how deep is the building? And based on that, E tab is going to work out the wind load. Now we gotta define which angle is the wind coming from? 0 degree is going this direction. From here towards the positive x. A 90 degree is actually going from here towards the positive y, and so on. So if you go to 180 is here negative x, and if you go to 70 is from here to the negative y. So let's start first with the 0 degree angle and click OK. The next parameter we're going to look at is our windward coefficient. For this parameter. It's very often 0.8 if you're building height is more than 25 meter. And even if it's less than that, sometimes you'll take it as 0.8 or it could be reduced to 0.7. But in our case it's 0.8, which is the default of e tab. So we'll leave that as 0.82 parameter is our leeward coefficient, which is the suction effect of the wind on the other side of the wall. And generally, he we don't have a pitched roof, so it's less than ten degrees. And our depth to width ratio is within one to 1.2 because almost squarish rectangular building. So our external pressure coefficient is suction, that's why it's negative 0.5 and which is the default of e-types. So we're going to leave it like that as well. Our area reduction factor is only applicable to cladding and roof. So it doesn't apply to the building lateral. Loads who leave that at one hour combination factor is based on design case g, where we are considering the windward wind loads and the leeward wind loads. This is the suction. So we're considering lateral pressure on the two sides here and we qualify for a wind load reduction of 0.9. So we're gonna go ahead and change that combination factor in E tabs 2.9, our local pressure factors only for cladding. So Lake Dallas One, and we don't have poorest cladding, so we'll also leave that as one. Now with our torsional moments. By default, ETags have it as positive torsion. But according to AES 170.2, if you building is more than 70 meter, then you need to consider that torsional wind loads. And it's at 0.2 times the width of the wind exposure. But in this case, our building height is definitely less than 70 meter and we don't need to consider torsional wind loads. Because of that, we're going to set this to know torsion. Now let's look at our wind speeds. Generally, we're looking at this project that's hypothetically here in Melbourne, which is a region a five. So for a building importance of T2 will looking at ultimate wind loads corresponding to an average recurrence interval of 500 years. And there's 45 meter per second for the ultimate load case and serviceability load serviceability when load of 25-years, ARI, which is 37 meter per second. If you're looking at an important factor of three, which is a hospital or a higher importance sort of building. You might start looking at an air I of 1000 and slightly higher wind speeds. Or if you're up in Queensland, you'll be looking at much heavier wind speed. But that's not the case here. So we're going to set this to 45, which is the ultimate wind speed that will be looking at. Later on when we add additional load cases for service wind, we're gonna change this to 37 meter per second, which is the 25-years ARI for serviceability design. Now the next thing we're going to be looking at is our terrain category. And that's a bit tricky because the Australian Standard has an intermediate categories that ETags doesn't allow you to define which are 1.52.5. So generally if you're a 2.5, I would say go to tearing Category two. And if you are at 1.5, go to the conservative one and B at terrain category one, you'd always want to be on the safe side. Instead of being on the higher side, which could be less conservative. Category one is usually if you have a building next to the ocean where there is no obstruction at all during category to if you've got very small sheds and trees and figured a park next door, for example. Two in category three is we've got some housing next to you that's want to stories or even could be three stories apartments. During Category four is way you've got more than ten meter high buildings and they're very closely spaced like the city center. Now be careful with the tiering category because it could be different in different directions. So for example, you could have different Turing categories over a certain direction, but another direction you could have an exposure to the ocean. And in that case, for that, when their action, let's say that's the west wind. You're gonna go with tearing category two. But if you're looking at the East Wind, you're gonna be using Tyrion category one. So be careful with that and always keep in mind choosing the correct theory and category. I usually referred to Google Maps to see what's the terrain like. If I cannot have the time to actually go and see for myself on site. Now let's start looking at our directional multiplier. Again, we're in Melbourne region A5 from table 3.2. We'll see that the North Wind and the west wind are the worst cases with a full directional multiplier of one and the other directions could be reduced slightly. Now in this case, I've defined the angular 0, which means I'm actually looking at the west wind. And in this case I'm actually going to leave that as one. But let's say if I was defining the angle as 90 degree, which is 0 to positive wide, that's a south wind because the south of the building, assuming the north is up here. And for the south wind, as we can see from here, it is a 0.85 directions multiplier. So I'll put that as 0.85 for example. Now we've got a shielding multiplier and topography multipliers, which I usually leave as one, unless the building is on top of a hill or something like that. Then he sought to need to look at the biography multiplier. The last factor we have to consider the dynamic response factor, which if you look at section six from AS 170.4, you'll see that you don't need to consider the dynamic effects if your frequency is more than one hertz. But if your frequency is less than one hertz, then you actually start to need to consider it. If it's a very small frequency, which is less 0.2 Hertz, then you cannot use a design code if it's in between 0.21, then there is a very long equations that it's just, you have a spreadsheet calculate for the long and the crosswinds. And if you periods are less than 0.4 hertz, the first two fundamental periods are less than 0.4 hertz and there within 10% of each other. Again, you can have to go for a dynamic wind tunnel testing of the building because the standard is not going to cover it. Now, if you quickly want to check if you building, it's actually going to qualify for this or no. As a rule of thumb, for each one story in your building, you're going to have 0.1. second as your period. And then one divided by the period gives you the frequency. So let's say we have a ten story building. Ten times 0.12 gives you almost 1 second period, which is equivalent to one hertz. So if you have a two-story building, you're looking at 20 times 0.12, you're looking at two seconds period of the building. Converting that to frequency one divided by two seconds gives you 0.5 hertz. So you start to fall into the region of 0.22 to one hertz and you start to need to actually calculate the dynamic when loads, unfortunately eat tabs doesn't calculate the dynamic crosswind than along wind. It's a little bit too complex and it's not covered in the O2 wind load calculator in e-tags right now. So you can have to calculate that separately in an Excel spreadsheet and calculate the wind load manually and then assign it to each flow manually. Alright, so we've covered all of our factors now we just go define which stories the wind loads applied to. And we've got a from the base up to level nine, are we going to assume there is a 1.5 meter parapet at the top of the building. And let's click OK and click OK. Now we've defined our first wind load case, which is our west wind. Generally, I would suggest that you define at least the west and the north because these are the most critical wins and the other load cases are much less because the directional vector that you're looking at. We also still guide define our service when a quick trick. Because usually if you work out the numbers, the service when compared to the ultimate, when it's a factor of 0.68 times the ultimate win. So sometimes I just opt for using load combination, that's a factor of the ultimate, went to save some time in defining those surface wind loads. But for your first time out suggests actually calculated yourself and make sure that you're confident with the loads that you defined on your building. Now if you've got a crosswind load case where you are going to assign your wind loads manually. I've actually got to load patterns at add my wind load case, and let's call this WM. And let's set this to a wind load case with user loads defined. And let's add that. We go to modify lateral loads. And here we can input our FX FY and torsional moments manually. I could also do it this way if I have the wind loads from a wind tunnel test done by a wind engineer, and I'm no longer using the automatic wind loads. That way I can just define my loads and moments directly on each floor as quickly as possible. You could have it on a spreadsheet. And you can click control c and control v here. And it's going to fill it all for you so you don't have to go and type it one by one as well. Now that's it for wind loads. I'll see you in the next lecture in defining some of our earthquake loads. 18. Earthquake Design: Now we are ready to start looking at earthquake design for our building. First thing to look at is actually the design code that we are going to be designing two. So this sort of a framework that a S11 70 force justs, and we're just gonna do a quick checks on the items that we're going to be designing two in here. So the first one is determining our importance level for the structure. And that is to a S11 70 and the BCA. So if you have a look there on AS1 170, we'll see that table where we can get an idea of which importance level our structure is. And similarly, there is another table in BCA and structural section as well. Most of the buildings are gonna be under ordinary failures except for super tall buildings that have a big effect. If anything goes wrong, then it could be a design importance level three or four. Now there's further detail in table 3.2. We're actually goes into descriptive explanation of what falls into category to category three, category four. And basically, our building is not qualifying for any of these. So it's only an importance levels too. So if we jump to Table 3.3 to find out what our annual probability of exceedances or the design probability that we designing to our building pretty much. Then we can see that for most buildings it's a 50 years design. 25 years or five years is usually for temporary structures, and 100 years is for bridges or super tall structures that are designed for unusual design lives here in Australia. So if you look at 50 years also the common design importance categories are 23. So for design category to like what we saw in the wind, we're using 1500 years probability of exceedances of earthquake. It's also the same. And for the service load case, it's one in 25 years as well. If you look at importance level three, we're going to see that the probability is actually reducing. So becoming 1100000 for wind and earthquake, which means a higher design load. Now, this is a statistical probability based approach based on reliability studies done in each country, based on the historical data. So it will be different from country to country. So be mindful of that and be aware of the design values that you are going to be designing to in your region and in your country and in your project as well. Now if we jump to the Australian Code 170.4 for earthquake design and we look in terms of what this and probability of exceedances means in terms of our probability factor. We'll see that one in 500 is probability factor of one. That's our importance level to an important level three will see that there are probability factor is 1.3. Basically what this means is that An important level three building should be designed to a bigger earthquake that only happens once in 100 years statistically. And that correlates to a design force that is 30% higher than a one in 500 earthquake. So that's what it means in terms of numbers and for service, it's always the same one in 25 years. And that is only 25% of your ultimate earthquake design. Now one in 50110000 is much less than one in 2 thousand or even four thousand, five thousand that other countries may adopt. But that's because Australia is not a high seismic activity region. And know that there's no high probability of that happening here. If we start looking at what's the hazard factor in the city or the location where we designing our building to. We're going to need to look at table 3.2 and AS1 170.4, the earthquake design code. And our building is in Melbourne, so it's going to be 0.08. Now if you notice in some places like for example, the cold coast is only 0.05. But now in the new revised earthquake design code, the minimum is 0.08. So if you designing a building in this region and it's less than 0.08 is be mindful that you have to design to the minimum of pin 08. Now if you're designing in a region where there is no information of it available here in the design code, you could actually jump. You could actually jump online to the J Science Australia map for the seismic hazard factors. And you can see here, for example, Melbourne is somewhere here, and it's in the orange region, which is between 0.6.08. The Australian coaches takes the hire of a which is 0.08. Now if you go to the East slightly, some places in Dandenong, for example, over here that will start to fall under 0.08 to 0.12. And if you go further to the east over here, that becomes much heavier to design to. That is Sydney over here similarly as well. So if you didn't have the data available from the table, you can actually look it up on the map of the city is not listed here. So in our case it was Melbourne, 0.08. So we've got our hazard factor, we've got our probability factor of one. Now we need to look at our site subsoil class. Now this is usually classification than by the geotechnical engineer. But once you've done some projects in your city or in the same ALU will be able to sort of predict what it's going to be if you don't have the information yet. If not, you can always start with the worst one and improve it later on. If the genetic information comes in with a better result than what you expected or your preliminary assumed. In this project. It's in Melbourne. Sometimes the soil is class B or C, and occasionally in very rare occasions it could be soil Class D. But let us assume that this is a soil Class C E. And we got confirmation from the geotechnical engineer for that. So we're gonna be proceeding with our design based on a class CE, which is a shallow soil. Now, with all of this information, we can put it into practice. Finally, so we can look at our table 2.1 and the AS1 70 for the earthquake design code. We've got our importance design level. We've got our soil type, we've got our seismic hazard factor, which is 0.08. We know our building height is in between 1215 because it's only 35 meters high. So our earthquake design categories to with this information, then we can go to earthquake design Category two and see what are the requirements to design for. Now with that in mind, earthquake design category two in Australian Standard is requiring you to do a static and analysis. But it can always opt for using a higher analysis level. As highlighted over here in section 2.2 of a S11 70.4. So for example, in this case we are only required to do static analysis because it's an earthquake design category two. But we already have our building modeled in 3D in Etypes. So we might as well do a dynamic analysis which gives you a more reliable information because we know that it's a better quality of information in terms of the spreading of the load across the building, in terms of any eccentricity or if we have any torsional behavior in the building. So if you've already got it there and computational power is really not that complex for you anymore these days. I'll suggest just going with the dynamic analysis. It will also give you in most cases at least less design forces. So you end up designing more efficient structures and actually adding great value in your building and towards achieving sustainable designs. Now we figured out which design category we're going to be designing two. So let's jump into detail and see how to do that. 19. Static Earthquake Design: Now let's see how we define our aesthetic earthquake load case in ITA. First thing is we've actually got a defined our mass source first. So we go to define mass source, which is going to be the weight of the building that either AB is going to use to calculate our earthquake force. By default, it comes with one mass source load case. Let's modify this and set it to the correct mass that we want to use an earthquake analysis. If we look at section 6.2.2 for calculation of gravity load, that's going to be used in our seismic earthquake load analysis. We'll see that acquired to include the total dead load plus a portion of the live load. That's a quasi-static factor of live load on the building. So the dead load is fairly straightforward because we can include that component with the self-weight and the superimposed dead loads. For live load, we actually take a portion of that and that is that portion is 0.6 for storage buildings, 0.3 for all other live load applications. Now, I don't go into complexity of defining different load cases for storage loads and for other live loads for the purpose of calculating the mass building. Because most buildings don't have that huge storage component into them, except if you're designing a warehouse or a storage center. And in that case you should definitely use factor of 0.6. Now lets see how we define that an ETF. Let's leave the name as it is, and let's take the option for specified load patterns to define the additional live load. So by default it includes the elements self masses. So we don't need to add the dead load anymore. We only need to add superimposed dead load, hence affected by one. And we need to add a live loads with the factor of 0.3. And also our reducible live loads with the factor of 0.3. Now in the case where you didn't have a superimposed dead load and it was directly included into the dead load load case. What you don't want to do is you don't want to add the dead load and have this ticked because that will double up the self-weight of the building and you will end up with very heavy earthquake forces. So in that case where you're not having a superimposed dead load and you only have a dead load case. Let's see him like this. Make sure to untick the elements South mass, so you don't double up the mass of the building. But that's not what we have. We have our dead loads defined in bed load and we have our soup rebelled loads defined separately. So we can add them like this. Now let's click OK and click OK. Now that we've got our masses defined, we can start defining our static earthquake load case. So let's go to the fine load pattern. And let's call this one earthquake static. Change the type to seismic load case. Again, you could leave it as none. If you want to assign the loads manually on the building, or you could leave it to use a load if you want to define it towards the diaphragms at the building, also manually. But I'm actually going to use the Australian or to the finishing that the e-Types uses to calculate earthquake loads because it's actually quite handy. Let's modify the parameters to that. So the first step we're going to be looking at is the eccentricity of the earthquake load. By default, E-Types has all of them check. And if you actually look at AS1 170.4, section 6.6 for torsional effects. You'll see that you actually need to consider the 10% is electricity for the earthquake load application and it's a plus minus load eccentricity. So ETags by default includes that eccentricity factor at included in a positive and negative direction for both x and y directions, which is very helpful. Now one thing that you might want to do is actually you want to switch off the y-direction and leave only the x and then define another one for y direction only and not X. Because later on, if you look back over here, you actually need to combine them with 100% from one direction and 30% from the other direction. And if you have the two directions, very centricity defined in one load case, you not going to be able to do that because what it helps is gonna give you is a load envelope of all of the six cases. But you cannot actually pick one of the six cases yourself and combine it with another one from the six cases internally. For that purpose, we're just going to do the x-direction in one load case and do the y-direction in another load case. Alright, now let's look at our story range for the earthquake. That's an important one to actually understand how to define the height of the building. Now your, your base story for earthquake is defined as basically the story that is already fully enclosed with earth. So when the earthquake comes and the soil starts shaking, this base is shaking with the soil. It's not something that's suspended from above. So if we look at that option a, where we've got a basement and the basement is basically back filled and it's forming one part with the ground. So you actually lost story is the story that matches the external ground level. But in the case b, where actually we have the basement sort of open and it's not really enclosed by soil on all sides. Then the shaking is actually starting from this bottom of the basement and not from the ground flow. Similarly with this one, if you have an open cut on one level, but you have a backfill on the other level, then you're shaking. Starts from the lower level, not from the higher one. In our case, we are going to assume that it's just sitting on the ground and it's all the way from the base of the building to the top of the building. Now the next section that we're going to look at is actually our parameters. First one was decide subsoil glass, which. The define this C based on what we received hypothetically from the geotechnical engineer, how probability factor is one, which is what we saw with our average recurrence intervals. For an importance level two building for the hazard factor in Melbourne, we've seen that it's 0.08. Now with the performance and ductility factor is a little bit tricky because it depends on the structural system that you're using for lateral load resisting. In this case, we are using a concrete structure and we're using a limited ductile shear walls, which gives us a ductility factor of two and a performance factor of 0.77. If you were using the tile shear walls. Now, the question here is which one you can adopt. It's not really something that is fixed. You choose which system you are using in your building. So for example, if you say okay, I'm gonna go with a ductile shear wall system where you have, you have to make sure that the actually design that activity requirements in your sheer walls and in your core walls and in your columns. If you're using a frame building to actually achieve this ductility behavior. In this case, we're actually just going to detail it to a limited ductile shear walls. And design for a ductility factor of two and a performance factor of 0.707. What that means is if you actually look at the SBA over mu factor over here, it's only 0.38, which is 38% of the earthquakes sheer force there we're going to calculate. Now why are we only taking 38% of the shear force? Let's have a quick look at actually, what does this structural performance factor and ductility factor means for our earthquake forces? If we look at the equation here, will see that we've got a probability factor. We've got our hazard factor. We've cut a factor that depends on the soil as well as the period of the building. And then we multiply all of that base shear force by SBY over mu, which we just saw was actually 0.38. So we're actually reducing our earthquake base year to 38% only. Now, the logic behind that is because the building doesn't actually need to resist the full force. The building can actually start to deform and it becomes slightly weaker. So it moves with the force instead of resisting it to 100%. And for all, in order for that logic to actually be true, we have to detail the structure is such that even though when it starts to crack and becomes plastic and flexible, it doesn't collapse. And hence y, if you actually going to adopt a higher factor, there is more honors and more strict requirements to detail your urine enforcements in your concrete structure to achieve that higher ductility. And in fact, in the Austrian standard economic go any higher than three. If he go any higher than that, you actually get a start looking at the New Zealand code. For most structures. You wouldn't need to go above that, especially in Australia. Now, in this project, I'm actually going to be adopting a limited ductile shear wall with a ductility factor of two and LSB of 0.77, which is by default what E-Types has defined for me over here. Now the last thing that we need to look at in our static earthquake definitions and ETypes is actually our time period. And you've got three options over here. So if I refer back to the natural period of structures, section 6.2.3 from a S11 70.4 earthquake design code. We'll see that we've got a fundamental period over here of the structure. And this is an empirical equation that uses factor that depends on the type of the structure that you're using, as well as the height of the structure to calculate the fundamental period. So you could actually calculate it manually and then inputted as user-defined period into E tabs. Or you could actually use the approximate option and input the K T factor, which is 0.05. for concrete structures. And let E tabs workout this T1 value and uses it in its calculation, in its calculation. Or you can actually use the program calculated value of the period and input the KT value. Now, e-Types manual is not very clear as to whether this program calculated value is actually being checked. That at least 80 or 70% of the T1 calculating with the empirical equation. For that purpose, I tend to prefer to just use the approximate period to calculate it to this value and just stick toward the code asks me to do for the static analysis because I don't want to keep checking the period that either EPS calculated and go back and forth checking that. So I'll just use the calculating the empirical equation. So our input data as 0.05. and use approximate method and click OK. Now don't forget that we agreed that we are going to be doing this only in the x direction. So put that and click modify load. And we'll create another load case and the y direction. And similarly, we're going to close all of these. And we're going to input the same parameters that we've used for the static earthquake in the x-direction. And click OK. And we've got our two static earthquake load cases. In the next lecture, we'll look at defining dynamic earthquake load cases. See you then. 20. Dynamic Earthquake Design: Now we're going to look at defining our dynamic earthquake response spectrum load cases. First thing we gotta do is actually defined our mass sources, which is exactly similar to what we did with our static earthquake load case. And the mass source is exactly the same, so we don't need to change anything. Just if you didn't watch the static load case application, make sure to look there for how we define our mass for the earthquake analysis. Now let's look at defining our modal cases. Let go to define modal cases. And we will see that by default, ETags has Eigen modal load cases setup, modify it. We'll see that we have about 12 modes that we can carry out. Actually, it's recommended from E tabs that when, when we are going to use a modal analysis to do our dynamic earthquake load that we carry out the analysis using another modal case type called the Ritz analysis. So we're going to set up another one here to the red's analysis. And we're going to call this Red's modal analysis. For example. What we want to do is we want to add or accelerations in three different directions. The first one, we going to add that as acceleration in the x-direction. And we can add another acceleration in the y direction. And we're going to add a third acceleration in the z direction. Or Z is a torsional modes of the building. Ux is the more than one direction in the x-direction. And new, Why is the mode in the y-direction? Now these three modes are the most important three modes for the structure of the building. That's why I add these three modes and they have to be accelerations. Now the number of modes is generally as much as required. Now how much is required? If we look at a S11 70.4, section 7.4. For modal analysis, we need to have sufficient modes to capture at least 90% of the mass of the structure. And if there's a period that's less than 5%, we generally should disregard that. Now for that purpose, I generally just liked to be comfortable with having 95% of the mass structure capture the my analysis. And a good starting point is to have many modes as the high and the number of stories in your building with a minimum of say, six to seven mode. In this case we have nine floors. So 12 modes. A little bit too much. Let's just set it tonight mode and click OK. Now we've got our two modes in here. Let's click OK. And let's actually quickly run the analysis. Let's choose which cases we're running first so we don't run unnecessary cases. Let's put don't run all. And I'm going to switch on my red's analysis and my Eigen model analysis. And switch on my Dad on live loads as well. And I'm going to let it run the analysis. Now the reason that I'm running the analysis is actually I want to see how much of the modal mass participation ratios is captured by these modes. So I have sufficient confidence that have captured enough of the structural behavior to say that my dynamic analysis basically valid. Now it's finished running the analysis. Let's go to display tables or a shortcut Control T. Now let's go under structural output, model information and let's choose modal participating mass ratios. And let's click OK. That's gonna give us a table. And basically what we want to look at is the some UX, some uy, and some RZ. That is the total participation of the mass in the periods in the x direction, the y direction, and the torsional. So if we look at the Eigenanalysis, let's see when it creates the 90%, it reached 90% in the X after eight modes. It reached a 95% in the Y of ten modes, and it reached 90% that torsion quite quickly actually by the fifth mode. So for the Eigen, we actually needed at least ten mode. And after 12 modes, it still only captured the 90% of the, of the x-direction modes total mass. Now let's look at the Ritz analysis actually and see what it's done. So attrition ninety-five percent at nine modes. It reached the 95% in the y-direction after eight modes, and it reached ninety-five percent also quiet fast after six months. So we'll see that we actually got a higher total participation ratios with less number of modes using the reds analysis. And for that purpose is actually recommended for dynamic earthquake design. Now I'm satisfied that I've reached at least 95% of my modal mass has been participated by these nine modes of the building. And that's sufficiently captures the behavior of the building to give me confidence in my dynamic analysis that I'm going to do later on. So with that, I'm quite happy. And I'm gonna proceed on with defining the rest of the parameters for my dynamic analysis. If it was less than 95% for the reds, are probably increase my mode slightly until it reaches that limit. Let's unlock our model. And before we forget, let's go to the load cases and make sure we switch off her Eigen because we don't need it anymore. We just going to be using our Ritz analysis for the earthquake. And it takes a bit of time to run. So that's why I just like to leave it off or even deleted from the model if you don't need it at all. Now let's look at defining our response spectrum functions. That's good to define. Functions response spectrum. By default, there is a response spectrum there. That is to make and standards. Let's delete that one and choose a function to Australian Standard, and click on add new function. Now we're going to name this function AS 170.4 and give it some information about what we're defining into it. So let's say that is limited. The tile shear wall and the soil class of C, E, and K, P of one, for example. So let's input these values are probability factor is one or hazard factor is 0.08, hour, performance factor is 0.772. And we don't need to change anything else. Pretty much our damping ratio is 0.05, which is typical for concrete structures. Let's click OK. And OK. Now I know that down the road I'm actually going to need another response spectrum function to check for cracking, which is actually instead of limited ductile behavior, it's just none that fell behavior at all, which is 100% of my earthquake force. So let's go to the define functions and go to response spectrum again. But this time let's select the Australian Standard and add a new function. And we're going to call this ONE AS 170.4. But we're going to call this nun ductile shear wall system with soil CE and same probability factor of one. So let's put that as one. Our hazard factor is the same as 0.08. Performance factor is the same but are the purity factor is one. So this is for structured that don't have any ductility. And we'll see how we are going to use that later on to check our walls designed for cracking. Let's click okay and a k and save our model. Now let's look at defining the dynamic load case itself. So let's go to define load cases. And over here, let's add a new load case. Let's call this, for example, says make earthquake dynamic with a limited ductility shear walls. Now, we gotta define the mass source. It's by default the only mass source that we have. This is not a linear static load case. This is actually a response spectrum load case. Now, while we gotta define here is our acceleration functions, which we just defined few minutes ago. So let's click add and choose acceleration in the U1 direction. But this is our limited tactile shear wall function. And lick the scale factor as it is. I know that some codes scale up and down these valleys, but an Australian Standard, we don't kill it. We leave it as it is, which is equivalent to the gravity function pretty much. And now we can add another exploration in the second direction. Again, it's delimited file she will System and we don't scale it at all. I also know that in another situations, in other codes, you actually give a start checking your U3, which is the vertical acceleration of the earthquake. But again in Australia we don't do that, so we just stick. So our accelerations in U1 and U2. Now we gotta define the red's modal analysis as the modal analysis that we're going to be using this dynamic earthquake. And it's recommended that we leave our modal combination a, C QC directional combination factor. A lot of countries recommend to use as RSS. Unfortunately, in Australia, we still need to combine our loads using 100% from one direction and 30% from the other direction. And because of that, we have to change this an absolute combination factor and change this to 0.3. So what it does, it actually combines the principal direction 100% and takes 0.3, which is a factor of the secondary direction, and combines them together and gives you one result at the end of the day. Now if we look at the modal damping, that is set as 0.05. which is what we have for concrete structures. Or diaphragm eccentricities is set for 0. But remember that one has to be at 10%. Like what we've just seen from the torsional effect requirements. That's the one over here. And now we're going to click OK. And we have our dynamic earthquake load case defined. Now, just to check this combination load case, I'm actually going to define another. I'm just going to add a copy of this load case. We're gonna call this earthquake X. And I'm only going to leave the U1 and delete the U2. Gonna leave this as SRS. S probably doesn't make a difference. And let's create another one. Added copy. And we're going to call this earthquake. Why? And we're going to actually leave the U2 and delete the U1. And again, we'll leave this as SIS s. Let's click OK and click OK. Now what I'm gonna do is I'm going to run the analysis and I'm actually going to compare the results of the dynamic load case that combine the x and y for me with 0.3 factor automatically and manually creating a look combination for 100% x plus 30% y and see the difference in the result. So my analysis is finished. And now what I'm gonna do is I'm going to quickly define the load combination. For my earthquake, x dynamic analysis for a limited the tile shear wall plus 0.3 of the earthquake in the y-direction. Dynamic with limited tactile she wall system. So can I change that one to my earthquake X with a factor of one and earthquake, why would the factor of 0.3? I'm going to click OK. And I'm going to create the other load case through using a copy command. We're going to leave that as one. And actually I'm gonna put that to be 0.3. just noticed that this should be an EQ. So I'm gonna change my factors here, swap them, and click OK. Now let's open our table this time using the shortcut Control T. And instead of looking at the model results, we're gonna switch that one off and we're actually going to look at the base reactions, turn it on, and select our load combinations, and select the load cases we want. Basically we just want to be looking at these three for now. And let's click OK. Now we've got our table. Generally look, this is our dynamic load case that combined it automatically and give us a four thousand, nine hundred and twenty and three thousand two hundred with an overturning moment of thirty seven thousand and ninety three thousand in Emax AND MY respectively. If we look at the combined load case, which are these ones, we see that we've got exactly the same shear force, 4,920 in the x direction. And in the other direction we've got actually 3,200, which is exactly what we got over here. If we compare our overturning moments, 373390, exactly the same. If we compare 93 thousand. This one also captured on 3 thousand hour torsion is actually given as the worst case, which was from this combination. So that confirms and that you don't necessarily need to define the dynamic load case in x and y direction separately. You can have them in one case and combine them using the absolute combination method with a factor of 0.3. What that is going to do is going to give you the worst case, but it doesn't give you any detail information more than that. It only gives you the worst-case. If you're looking for manual combinations of x and y directions, then what you have to do is you've gotta define the x load case separately and then define your wind load case separately, and then go on and create your load combinations to get all the breakdown of the envelopes. If you're looking to do that, for example, for design of your raft or something like that. Or if you're looking for the torsion load cases that could be different based on different cases. But most of the time, realistically, what I want to be looking at is just the worst envelope of the earthquake load cases. If for some reason I needed the breakdown, then I have the option to go on and do that in my dynamic load analysis. Now one last thing that I need to define in my dynamic load cases is actually than non ductile shear wall system dynamic load case. So let's go to define load cases again. Let's go to our enveloped case and create a copy of that. Let's call this earthquake dynamic non ductile shear walls and make sure that we switched our functions to the non ductile she will Systems. And let's click OK. We are going to need this nun tactile response spectrum as well as the limited ductility Shuo systems when we start designing our walls because we need this one to check if our walls are going to crack and modify the stiffness accordingly. And we need this one to actually design the stresses, the boundary elements and the tension forces too. That will make sense much, much more later, but we just going to define it for now. So when we start designing later, we have that information available. Now let's click OK, save our file. And in the next lecture, we're gonna go into more depth into defining our load combinations that we're gonna use to design our structure later on in the course. See you then. 21. Load Combination: Now let's look at some load combinations that we're gonna be using in our design. Let's look at section four from AS1 170. And there we're gonna see the load combinations that we should be designing to the stability of those combination as trends have very similar with the exception of this one that's not in strength load combinations and an exception for that, which is the tension design combination for the wind load pretty much otherwise, they're fairly close. Now let's look at the strength and load combinations. The first one is our 1.35 times the dead load of the building. This is a lot combinations that might actually start to govern if you have a very heavy structure with fixed labs, big columns, m, fairly little to no live loads. If you have a lot of live load reductions on apartments and things like that, that might actually start to govern for high-rise building. Let's look at defining load combinations. These two load combinations were the ones that we use to check our earthquake design. Let's just delete them because we don't need them anymore. And let's create a new load combination, 1.35 g. And let's change this factor 2.351 and add also our super-imposed that loads which are 1.35. And click OK. And there we go with defined our first load combination. Now with defining the other ones, we could go on one-by-one and define the manually. Or we can also use the add default design combinations from ETF. Since we've defined the correct design code, which is Australian Standard II, tabs automatically builds up the load combinations for you based on the load case type that we defined that live wind and earthquake. So if we create new ones for the concrete Chou wall design and convert them to user combinations so we can edit them later on and click OK. We see here that e-Types of actually generated 46 load combinations for us. Let's see what E-Types has generated. So the first one was the 1.35, which is what we've expected. Second one was the 1.2 dead load and 1.5 live load, which is also what we've expected. Now, we can actually go on and start adding some description. So we don't need to jump into the load case to see what that is. We can just see it stayed away from the description. Click OK. Let's do the same here. Let's call this 1.35 j. For load case three. Now ETag started looking into introducing the wind load. And it used this equation which is 1.2 g plus wind load plus portion of the live load, which is 0.4 for the live load. That is not storage. And we've got the 1.2 factors for bed and super-imposed and the wind one, which is perfect. So let's call this 0.2 j plus our 0.4. Q plus our wind one. And I'm actually going to copy this, so I don't have to keep typing later on. And I'm going to click OK. Now case number four, E tabs of added a negative direction for that. But in this project have actually defined the wind from the four directions. So I don't need the negative value. I don't need that reverse load case for the wind. What I'm gonna do is I'm going to delete this load combination. Let's look at case five. That's my wind too. So I can straight away base my texts and update the information. K6 is my reverse when two which don't need, okay, seven is my Wind. Three, following the same pattern. Eight is actually the reverse, which I don't need. Case nine is my wins four. And case then is the reverse, which I don't need. Now let's see. Case 1111 is 1.2 g plus the wind straightaway, which technically speaking, you wouldn't have. Generally, because this is a compression load case in most of the time because you are taking a bigger bed load factor and you are taking the full wind load. So adding in the live loads, which are often compression, it's very rare that you have an uplift live load case except if you're designing, for example, for water pressure load cases, which were not in this case. So we don't really need that load combination. And it's going to create a clutter in our load combinations that we don't need. So what I'm gonna do is I'm going to delete this type float combination instead of leaving it in there. So I'm gonna delete it. Think it's 12345678. Now load case 19. That is my 0.9 dead load. Then my one wind, which is my wind up lift. Now you see this load case is using a minimum of the dead load, doesn't take into account any live load, and it takes the full wind load into account. Now this is an important case because in this case you can get the maximum tension in your world because you're dead load helps to resist the uplift from the wind. Now let's this is also the reverse, so it's the same pattern that e-Types keeps using. This is my W3, and I don't need my Depth-first W3, and lastly my W4. And I don't need my reverse of w For now. What is my 27 load case? That's a full dead load, 30% live load, and a full earthquake static load case. Now that is an important load case if I'm designing to aesthetic earthquake load case. So I'm going to leave it there. I'm gonna call it g plus 0.3 Cu plus my earthquake static, the x direction. And we're gonna select that so I can copy it to the other load cases. Now this is coming from the load case. Over here, G plus earthquake plus a factor of your live load. Let's click OK and see the load case 28. That is the reverse of my earthquake. So I'm gonna leave that n. Oops, looks like I didn't copy the text from the previous one. Let's take our text. So we're gonna have to keep typing it. And let's define it here. But this time it's actually the reverse of my static load case. This one is now my static in the y direction. And this is the reverse of my static in the y direction. Now if you notice one thing it's doing here, it's actually for getting the contribution of 30% from the other direction plus the main direction. So it is only having my static load case that is 100% in one direction and 100% in the reverse direction, but there's no combination for the y direction. So we're going to add this one manually through going here and actually adding 0.3, my earthquake static and the y direction. And we're gonna click Add. We're gonna select our earthquake static in the y-direction. Eq, why static? And it's only going to take a 30% of that. Now, that is the positive EQ. Why we still need the negative very present for the reverse of the 30% as contributed. So let's add a copy. And this one, we'll call it. Actually, let's copy the text from here so it's easier to edit. Copy all of these texts and click OK. And we're going to add a copy of that. And we're gonna call it 27 a. And then we're gonna say that this is going to be the negative 0.3 from the Y direction and our factor should be negative 0.3. Similarly, we're gonna do the same with the negative x and positive 0.3. So what we're going to define here, earthquakes, that a, that's only three. Added. Again, our earthquake static in the y direction, that is a positive 0.3. And what we're gonna do is we can create a copy of it. And we're going to call it 28 a. And that is going to be negative earthquake setting in the x direction and a negative 0.3 earthquakes static in the y direction. And we have to update our factors here and click OK. Now we've gotta do the same with the earthquake and the y direction. But I'm not going to spend time doing that for now. But you get the idea of how we add these cases later on. And these are the ones that you should be using when you are designing to the earthquake. Now let's look at our load combination 31. Again, this one, it's using the earthquake, but this one is without the live load. And this combination is actually not in the standard because we don't have that load case where we don't have live load but we have earthquake because remember, our earthquake load case is dependent on the mass of the building which we used live load to calculate. So it's counter-intuitive to actually have an earthquake load case combination that is based on no live load in the combination when the earthquake force itself is derived from a mass that includes that live load. Basically saying you have live load on the building. But you're not taking it into account, which is very conservative ends, right? So I'm gonna delete these load combinations. We don't need. Now the other load combinations which are actually using our earthquake dynamic. These are important ones if you are designing using the earthquake dynamic load combination. So this g plus 0.3 plus earthquake dynamic, and that's the simplicity of this load combination. It doesn't have a reverse because earthquake dynamic is fully reversible. So it could be 100% from one direction, it could be 100% from the other direction. And what a Tabs does, it only gives you one result. But when it designs the wall or the element, it knows that it's fully flat, fully reversible load case. So it actually envelopes the positive and the negative of it and then it puts it into one equation. You don't need to say it. It's just really simple. Now our 36 load case, it created the same load combination, but this time for the earthquake dynamic in the x-direction only. Now we created this dynamic earthquake x-direction just for the sake of comparison. Not going to be using it to design in the building because that means I need to add all of the other combination that we just added, the static load case, considering 30% of the y direction, which is already considered in my load case five with dynamic earthquake that uses absolute combination factor as we saw in the last lecture. So I'm also going to delete this load combination and the Y load combination. Now let's look at combination 38. This is an important combination to have. This is the non ductile shear wall load combinations. So this nun ductile dynamic earthquake combination we are going to actually use check the wall cracking later on. So we're going to leave this one on and we're gonna give it a name, earthquake, dynamic and ductile shear walls. And again, this is fully reversible and ETags understands that. So it envelopes positive and negative values and it envelopes all the plus and minus torsional eccentricities. And it envelopes all your plus or minus 0.3 contribution from the second direction. So it saves you a lot of time in creating combinations. Now, our combination 39, again, that is the useless combination without the live load, which doesn't make sense. So which is going to delete that one, that one and that one. And that one. And also that one. Same combination that doesn't make sense. Right? So we've done, we've added our reduced our combinations to the one that we're going to be using in our design. Now, we can delete this one that we manually define. Let's click. Okay, because by this time we spent a lot of time in defining our load combinations. And if by mistake, press escape, or cancel, it's going to all disappear. So it's very scary. Just gotta click OK. Yes, save my work so I don't waste my time in defining those load combinations. And what you might actually do in the future is that since you have a defined in this building and let's say you're going to be using that to these and other similar buildings when you start a new project, myself, starting from nothing. You can say, start from a model that you've done before. And you get all of these load combinations in. You get all your modal analysis and you get your dynamic earthquake analysis in the modal mass definitions and things like that. So it can be very helpful in the future. Now before we finish this lecture, let's have a second look through our load combinations from a S11 70 to make sure that e-Types actually covered all of the load combinations we want. We've seen that we've got the 1.35. Gee, we've seen that we've got our 1.2 g and 1.5 Q. We've seen that this equation is probably not for the design of the building. This is for other purposes. We've seen this equation here, which is also used for the design of the wind. Maximum compression. We've seen this equation for Design of when maximum tension. And we've seen our earthquake design load combination. And we don't have this load combination. This is basically for liquids or Letter of pressure, which we don't have defined in our building in this case, because we don't have permanent basements with lateral pressures on our walls and we don't have swimming pool on the building, for example, to include that live load into the building. So with that, we've ticked off all the equations that we need to be looking at for strength design. 22. Load Combination Part 2: Another load combination that we also need to define is our service when load. So if you recall from earlier during the wind load case lecture of actually fire off first when load case. And after the lecture I've actually added the other wind load cases as well with the correct direction multiplier as we spoke about, and with the correct direction as we also spoke about. Now, these are ultimate load cases. And these ultimate load cases are having a wind speed of 45 meter per second. As we saw earlier from the design average recurrence probabilities. If we look at our importance levels again, for a building that's important level to our service wind is one in 25 years. Annual probability of exceedances, which actually corresponds to a 37 meter per second wind speed for region A5, which is Malbec. Now, if you compare 37 meter per second to 45, and if you look how the wind pressure is calculated, the wind speed is actually squared. So if you divide 37 by 45 and square the result, you end up with a factor of around 0.68. Instead of actually manually defining additional for load cases for the service wind. What I'm gonna do is actually I'm gonna manually define load combination for that. So we're gonna call it wind one, PESTLE s. And my wind one is actually my north wind. So what I'm gonna do is I'm gonna select my wind one load case and put a factor of 0.68. Similarly, I'll add a copy of that and call it a wind too. I'm gonna change this to my when to load case and I have a copy of that gain with my 13. And finally, my wind. For now I've got the four service wind load cases, but unfortunately I don't have a combinations for them. So what are also might do is instead of using them for design and might actually look back at these four combinations. And I can add a copy of each of them. And I could call it Udi. You the wall. Three. But this one is actually going to be my SLS. And I don't need to write the whole thing again because it's already there. That's my W1. I'm going to save that. And I'm also going to have a copy of these ones similarly, and call them SLS. And changed my wind to my Celeste went. That way. I've added my load combinations for the wind serviceability. And I don't need these loads combinations to design the wolves per se, but I need them just to have a look at my core. And does the core actually start cracking at the surface winds or no. Now in this building, I'm expecting the design to be governed by earthquake and not when. So it's not very critical to be done on a building of this size. But if you have a much higher building, say 15 story or 20 story, wind starts to govern. And in that case, having the service when load combinations help you to identify if there would be any cracking in the walls or in the other lateral load resistance system that you're looking at. Besides the strength float combinations that we just seen, we want to create some load envelopes that quickly gives us maximum and minimum design forces to design for. We also do that through the load combination tab. So we go to define load combinations, and let's create a new manual combination. But this one is going to be an envelope. And for this one, we're going to call this ultimate limit state URLS design envelope. And let's add our load combinations. Are we going to be covering in this envelope? We've got our Udi will, one. Udi will too. And they're all scale factor of one because we just capturing the full load combination results pretty much. And we have all of our load combinations defined in one envelope. But if you notice, we still have our static load combinations here, and we also have our dynamics. So in this case, we're not really going to be designing to the static load that we've defined. So we're just going to exclude that from our envelope. Only going to have our Actually we also not designing our non ductile load case because that is only to check cracking and it's not a design combination. So we've got our dynamic earthquake load case, we've got our we've got our wind load cases. We've got our 1.21.5 cube, as well as the one-point 3.5G. So got our load combinations in here. And that is going to be envelopes so we can see the results later on. So lets click OK and now let's create actually another envelope. From this one we're going to call the earthquake dyadic envelope. And for this one also we are going to change the type to an envelope. But we're gonna be using only earthquake static load combinations. 23. Piers and Spandrels: Now before we start designing our structure, we first gotta do some checks on the model and the results to make sure that the results we're getting is actually sensible. And then we can proceed with the fun stage, which is the design of the building. One thing we gotta do first before starting our checks is signing purism spandrels to our shear walls and core walls because ETags essentially works with walls as meshed shell objects. And they don't generally give you the results of the whole element. In the end, they actually just calculated the stresses and the forces in the mesh. Now it has, it has a function called Pyrenean spandrel, which sums up the stresses and forces and give you a simple output in the end for that to make sense, let's first look at what is a peer and what's a spandrel from tabs CSI website appear is essentially a portion of the wall that is continuous across the whole length of the wall without being interrupted by an opening. If it gets interrupted over here, then it starts to become a different peer, for example. But here it's a continuous runs, so it's only one peer. Now, ETags uses peers to give you the results at the top and the bottom of them. But it doesn't give you the results at the right-hand side and the left hand side. For example, you get the moments at the top and the bottom, the compression at the top and the bottom, and the shear forces at the top and the bottom. Now, if you've got an opening that breaks up your peer, for example, then you've gotta use a different peer because it's no longer continuous. Otherwise it's going to add these two together, which is not true. Now if you look at spandrels, spandrels are actually like the beams. They span essentially between different peers. And e-types gives you the results at the left-hand side and the right-hand side of the spandrel. So you get the moments at the left and the right side of the spandrel, you get shear forces at the left and the right of the spandrel and you get the compression or tension forces at the left and the right side. So usually when you have an opening and you've got a deep beam that spans across the opening that is assigned as a spandrel. Similarly, if you've got a portion of the wall below the opening that spans across the two legs of the wall that is also assigned as a spandrel. Now not to complicate things, we don't need to perfect our pier and spandrel label assignments in our model. Except if we are allowing 100% on the design of these spandrels and PAs from e-Types. If you are going to be designed, some designing something like this with a strengthened time model, then you don't necessarily need to worry a lot about this pier and spandrel assignments. For the purpose of this stage in the course, we're actually going to define our whole course as one peer element. That way we can get actually our gravity and overturning moments at each story. And we simplify everything for this stage. Later on when we start designing our walls, We will start breaking them down into different pieces and different spandrels. But at this stage we are only interested in the load run-down and the overall distribution of the loads. For that purpose, we just gonna give them one big. Pier label for each core will. Now let's go ahead and do that. So let's go to select. And let's select all of our wall sections. This is the old sections we are using, let's like that. And show selected objects only. Just to make sure we're checking that we don't have any wall one or wall eight properties. Now, what we're gonna do now is actually we're gonna go to first define our pier labels. So we've got, let's call this core one. And let's call another one, called two. And let's click okay. If you go to the, if you just hover over the top slightly, or you could actually go to view, set, 3D view, and choose your XY view and reduce your aperture a little bit to make it a little bit more flat, let's click OK. You can start to see this is our core two. And we could give it the pier label through going to assign shell be label. And let's give it a core one. Let's select this core and give it a pier label core two. And let's close this. Now to make sure that what we have is correct. We could actually go to select by peer property, which is under labeled by the pier label. And let's select core one. And let's show only selected items. Yep, that's our core one. We have the whole thing as one core. Let's see if we select core two. We see that we've got 162 show selected. Let's right-click, right-click. And show selected objects only. Yep, that's our second core. We have it right there. That looks correct. Now one quick advantage of doing that early on is you could actually start looking at the properties of this core based on its section, as well as its opening. The way to do that is by going to our shear will design and click on the drop-down button. Go to define general peer section. And let's add a new peer section. Let's call this one core one, and let's give it a 40 MPA concrete grade. Now, in adding the peer, you could start from 0 or you could actually start from an existing wall peer. So let's goes our lowest level, and let's select our core one as our peer. If we open our section designer, we can actually start to see our coal Cornwall section. And if actually zoom in, we can actually see that enforcement assigned in there. We can modify it. We can add bigger bars at the corners. And we could actually get the properties of that as well. If we go to section properties, we can get our center of gravity for the core, we can get our areas. Second moment of areas and things like that. Let's click OK and click OK. And another k. So now that we've got our peers defined for each of the two core walls. Let's actually show both of them. So let's go to selecting the two peer to peer labels, which are selected objects only. What I am going to do is I'm going to actually run the analysis quickly and see how the results come out. Now my analysis finished running and I'm actually going to go to this play frame peers Pandora or link forces. And what I'm going to look at is actually I want to look at the gravity load for each core. So I'll leave on the dead load case on a look at axial force. And what I want to see is actually not frames. And I'm going to click OK. And when I switch on showing values at controlling sessions and diagrams. And if I zoom in, I'll start to see that I'm having about 7,900 kilonewton load here. And I'm having about 7,471 kilonewton of dead load in here. And that quickly gives me my actual load run-down for gravity for the corps. And if I actually switched to my earthquake dynamic load case for example, it can also give me my overturning moments. As you can see here. This core is taken about 63 thousand and this course taken about 62 thousand. I can switch to the weak axis moments. And I can see the moments on the other direction of the core. Now this is quite helpful way to quickly get the global results of each core or each wall that you have. But it's not sufficient detail to design your reinforcements for core walls. Later on in the course, we're going to go into detail into how we can define the peers correctly to get the correct reinforcements. But for now, this is good enough that I can actually start looking at my analysis results and reviewing, which we're gonna do in the next lecture. 24. Gravity Load Checks: Hello guys. Now let's start checking the results that came out of our model. The first thing is we're going to start looking at our columns loads. The way that we could verify their gravity loads very quickly is doing what we call an, a, a mythic calculation of the gravity load on the column. And that's basically just looking at the floor plan and working out the effective area that this column is supporting. And working out the loads per floor in terms of self-weight, self superimposed dead load and live load. And then we can work out the reaction on the column based on that is not 100% accurate because we have to take into account the different span length and the different support locations. Of course, the edge support takes less n, the first internal support takes slightly higher loads. But that's what he tabs is four, we can just do a very rough numbers to check that we are in the vicinity of the correct loads. Plus or minus 5, 5% is acceptable. So looking at the plan of this tower over here, we'll quickly see that we have a fairly regular grid here, 9.5 meter by 9.5 meters. The columns that are close to the core have less load because the core cuts the span here. And we really have only this one column here, one column here, and one column here that have a bit of flawed. Let's take this one column here and verified slowed. So let's open that up in an Elevation view. In this here, let's go to elevation and let's open grid D of the building. Now, see spoke before. The elevation usually looks in the positive y-direction when it's a cross x. So at this column over here, and you can actually see the grid location, which is D5 for this column over here, which is handy as well. Now, if you work out the area quickly just 9.5 plus eight divided by two to get the average load width in this direction. And the load width in this direction, you end up with an area of around 76.5 meter square. And we have 200 thick slab here that is 4.8 KPI. If you multiply the 4.8 GPA times the area which is 76.5, you'll be getting around. And also you've got to add in the self weight of the column as well. So that's a 400 by 400 column times 3.8 meter float floor height. So altogether is going to give you around 385 kilonewton. If we look here in our e-Types model and we go to look for our frame forces. Let's go to the case that load, which is the case that we've used for the self-weight. And let's click Apply. We're not going to take the roofing to account. And let's just look at this floor over here. And that is basically 809 minus 405. We are getting about a 404 kilonewton. Dead load, just self-weight only, which is very close to what we calculated by hand as 386. The slight difference comes from the fact that is the first internal column in your frame, which usually takes a heavier reaction then the internal ones, exactly like what you can see in this elevation here. Alright, let's have a look at the superimposed dead load. Again, if you calculate the area 76.5 meters square times by our 1K EPA superimposed dead loads. We are going to be getting 76.5. And what we see over here is around 74, which is very close. Similarly with our live loads as well. We can quickly calculate based on the area and will be getting about 230 kilonewton over here. So we're happy that our loads is generally looking fine. What will you might also want to do is we actually want to see that the load flows all the way from the top of the building to the bottom of the building. As we can see here, the load increases fairly consistent. There we go. If we can just switch between our elevations of different columns and we can see that the loads is going down the building pretty consistent. There's nothing unusual. There is no columns that's hanging and suddenly going tension and things like that. So that's just a visual verification beside the numerical calculation based on the load. Now we can also do a check for the slab deflections. So we can come here to the floor plate and we could go to our deflections. And let's go to a dead load deflection and look at displacement along the UCI, which is the vertical displacement. And let's click apply. We can see that we are getting big deflections in the internal spans here that next to the core. And that's about 38 millimeter deflections, which is fairly reasonable, which can be balanced by posts mentioning in the slab. If we look at our live loads for the flow, we are getting around 23 mills. Now this 23 miles is after considering a twenty-five percent stiffness only of the slab, assuming that is going to be cracked. And assuming that the rest of that load is actually gonna be pellets balanced by our post tension. So that's looking fine, it's looking reasonable. And also if I switch it back to the load case, you can see at the bottom here it says maximum and minimum. Maximum is basically an upward lifting, which might be at the corners here because the internal spans are going down, so they're lifting up the corner points, which is also reasonable. And the minimum which is the negative displacement of the slab at 740 mill, which is also reasonable, which means we don't have figured a 3D. We don't have anything that's crazy or logical happening in the building that seems to be very typical response. And we don't have a displacement that is, for example, 200 millimeter or even a 1000 millimeter. If you see that number, it actually tells you where is the location. Jump to that location and actually see what is happening there. Just so you can get an idea if there is any modelling error that you've made, a column, it's not connected or it's not supported or something like that. Alright, so we check the deflections, we checked the area loads, we check that the loads flow down. Now what we could do is you could also look at the live load reduction factors in our building. The way we see that is we go to the concrete frame design, click down and go to this play design information. Let's look for the design input and let's switch that to live load reduction factors and click Apply. We'll see that these are the live load reduction factors fairly after the first three stories, we are already reaching the limit. The minimum, which is 0.5. Now, if we work that using the formula from the code, you'll be getting very, very similar number. The only thing that I would have to say about that is that in the code It says that these that you use to calculate the live load reduction factor should be the AES that are supported by the element and for which the reduction is not restricted, which means it's not any of these areas. Now in this, in this building, we have the roof as a non reducible live load. So technically the first column the first floor of columns, should not have any live load reductions. So if I'm designing the columns over here, I would override that. I'd go to View revise overrides, and I'd actually go to the live load reduction and override that to one and click OK. Now the way I did that is because the first floor and it shouldn't have any livelihood reduction because my roof is not reducible live load. But if you don't have to worry about that because this load live load reduction is only applied in your design combination, it doesn't apply to the loads that you look at. So for example, if we jump to look at our live load reduced, sorry that is here. The live load produced. We work them out. If you follow them down the building, if you actually multiply this by the number of floors, you'll end up with the full live load shown here at the bottom. Alright. Now, taken out of that, if I do right-click here, notice that we have a live load reducible of 1000700. We have live load, this not reducible, which is 105. We have self-weight that is 3,222, and we have superimposed dead load, very 719. Now, if you factor all of these up, 1.2 times dead load plus 1.5 times the live loads. You'd actually be ending with something in this range, 7,434 kilometer. 25. Wind Load Checks Part 1: Hello again. Now let's start looking at our automatic wind loads that were applied to the building. And to do that, we first get a made sure that we are running the load cases because previously we select them, selected them as don't run. So we can select them and click run. So you can see the action now is R1. But while we are at it, we can also actually switch on our earthquake static analysis. And we don't need the modal analysis and let's click run now. All right, so our analysis finished running and now we should have the results of the wind load cases as well as the earthquake. Let's switch to our plan. Let's say going to go to level six. Let's switch off these contours by clicking on show undeformed shape. And now what we're gonna do is we are gonna go to display joint load, the signs which is here. Or you can also go to this play low the signs, the joint is the same thing. Let's look at our wind load case and let's click Apply. Now we can see that our tabs calculated our West when S 261 kilometers in a calculated our south wind. And also notice that the action that it's applied that which means we've put the angles correctly, that's 240 kilonewton. The east, we expected to be much less because the directional factor 131 only, we have the North, which is 330 kilonewton. Now, to verify these loads, we can just do a quick and simple calculation. If we actually worked out the design wind pressure based on the parameters that we've inputted in our load case. So if we go back, sorry, if we go to our load patterns, let's say the North Wind, and let's open it up and see the perimeters we've put in. So we've put a 45 meter per second wind speed during category of two with no shielding and with no direction or topography multipliers, that would actually work out to give us something around 1.6 KPI design when pressure. Now we also have to take into account our dynamic factors, sorry, not dynamic, our shape factors, which is 0.8 plus 0.5, that gives us 1.2. So we have to scale up our 1.6 cape wind pressure by 1.2. And then we can scale it down with our combination factor 0.9. And that ends up in the range of 1.73 KPI. So that's our design when pressure for north wind, only because the other wind directions are going to be slightly less than the west wind is going to be the same. Other actions are going to be less because the directional factors that we spoke about previously. So let's look at now we've got our design wind pressure, which is 1.73 KPI. The width of this building. Is actually 40.249 meters if you work it out. And our floor to floor is 3.8. So if you just take only one floor for the full width, we are going to have our design wind pressure, which is 1.73 times our width of the building, 49.2 times the floor to floor height, which is 3.8. That gives us something about 324 kilonewton. E-types is giving us 328 probably because the approximation that I did in the calculation, but it's very, very close. So I'm happy to see that the load is correct. Let's flip up and down the floors. The loads are fairly close. It increases slightly with the height because of the multiplier, the MZ factor. And at the highest floor it's less because it only has half the floor, floor height, only half of the highest level is applied. The proof the other half is actually a private level eight. Alright, so our loads generally seemed to be applied correctly and they make sense in terms of the wind. We can actually look at our wind moments as well. We could go to display story response plots. And we can switch the load case to the north wind that we're just looking at. And then we could also, instead of looking at displacement, we could actually look at O2 lateral loads to story. And we can see here that this actually could open a table with a detailed report. And in this table, if we go to the second page, we can see that this is the total load that we have applied and this is actually I'm sorry, I'm looking at the wrong case. This is the earthquake static load case. We are looking at the wind north. That's why didn't make sense. If you open up the report for this load case. We have the loads that we spoke about. That looks good if we switched the other load cases. Okay, that all looks good to me as well. Now let's switch to our overturning moments. And we can see that the overturning moment increases with the height. And we have a base moment of 52,004. The North Wind and the west wind is also the second critical one. Let's look at that one. We've got a 411000 here. Obviously that's going to be less now, 37 for the South when and only 20 thousand for the east wind. So generally, our, our moments seem to make sense. If we actually, we could also verify this very quickly based on the loads that we've just spoken about, which was what, 300, we worked out, our design pressure, which which comes to 1.73 KPI. If we just take the total building height and assume it's a cantilever from the base. So our total building height, we can take it from here. Actually, that's very 4.9 meter. So if we take it like a cantilever with a UDL load, actually let us open the North locations so we can compare the loads. Alright, so if we take 1.73 times by the building height, which is 34.9 square, divided by two, just like the UDL on a cantilever. And we times by the building width, which we worked out to be 49.2 meters, we get 51,836 kilonewton meter as an overturning moment and eat EPS calculated it to be 52,115, which is really close. So I'm happy with my design wind loads and verify them that actually eat abs, work them out quite nicely. We'll see you in the next lecture when we start actually checking the building to these wind load. See you then. 26. Wind Load Checks Part 2: We're comfortable with our wind loads, that they make sense so far. Now let's start looking at our building, whether it can actually withstand these loads that we calculated and verified this. Now, the first thing that we need to check is the columns and see if they actually cracked once they took any moment from our wind analysis. And to do that, we're gonna go to 3D and make our life easier. We are going to switch on our display toggles and switch off the floors and the walls for now. And actually the null frames. Well, let's click okay. So we only have the columns. While we can do now is we can actually switch our moments and go to our load combinations. We have four different wind load cases. And we have combinations for earthquake, and we have our combinations for wind. And at the end we have our envelope that we define. Let's look for our envelope, which at this stage mean that it will also include the result for earthquake. And let's look for our maximum and minimum moment on the principal axis, which is M33. And let's show values. Let's click Apply. Now, we can't see much of our moments on 3D. Let's switch to elevations view. Maybe it's going to be easier to see it from there. And let's apply our moments here, okay? So we can definitely see our moment here. We can see the maximum and minimum values for this first grid. Let's put this to apply and so we can see easier which group is that they will look at? We're looking at one, which means it's these row of columns along here. Now we need to know what our cracking moments for the columns and for that purpose, we can just use the spreadsheet as something you can develop yourself using the code that you're designing to. So we have 450 by 450 columns here with a 50 MPA concrete grade. And they are not having any pre-stress and just assuming a minimum of 1% reinforcements. So we get a cracking moment of around 45 kilonewton meter. When we look here, we see that actually most of them exceed our cracking moment, which means that actually most of them are gonna be cracked. Now, the next thing that we need to know, because our cracking factor, this I effective depends on how much compression load we have. Let's look at the ones on the roof. If we take this one, for example, we have about, let's take the low 1455 kilometers and compression. So let's put 455. That increase, increase it a little bit, which is actually not conservative. Because these are internal ones, the ad you on probably have less load. Let's look as we go down the building may be at this level here and see how much axial load we have. We've got 2550. Now that starts to make a difference because our factors go up quite a bit, and so on and so forth. Now, I'm going to actually be a bit conservative in my approach here. And I'm going to put very present stiffness for all of these ones. Sorry, I delimited select that one. These ones. That's also a helpful tip if you select from the top left corner and you drag cross, you only select the ones that are fully within the box that you just created. So the columns at the bottom are not gonna get selected. But if you do it from the top right corner down, you actually select everything that the box crosses, the columns the bottom are gonna get selected. And I'm going to click Escape and selected this way. So these columns I'm going to actually assign or will I have to delete my analysis? I'm going to assign property modifier to them. I'm gonna reduce their moment of inertia. It's only 30%. And the ones below, I'm actually going to leave them at 50%. Alright? We can assume that the results we've got along this line is going to be similar to the results we get along these grid lines. So I'm gonna go ahead and do the same for gridlines six. I'm going to select these ones from story three down. And these ones, sorry, it should be from story four down to 50%. And from roof to story for it's only a 30% of the effective stiffness. Now let's run the analysis again and see how that impacts the inter columns. Now remember the internal comms have heavier compression loads. So they might be actually okay as a 50% throughout, let's see. Okay, so our results are out now. And let's look at our moments again. Yep, our moments now have reduced for most of the floors, but that is because we've already reduce its stiffness. Now we're getting a moment of 30, which means more of our stability loads is actually going to the core walls instead of the columns because the columns are gonna get cracked. Now let's look at another grid. For example, grid line five. Let's see the columns along this grid line. We have the moments fairly close to the cracking limit, but they barely exceeded for this one and this one here. These ones are fine. These are fine. They don't exceeded only the higher floors. And these two are think it's safe to say that these ones here would need to be cracked. And these ones here would need to be cracked. Now, how much compression we have? We probably have very good compression here. Yeah, we have about 4 thousand square foot. Plug that into our formula. We are getting only 70% stiffness, which is good news for these guys. But the one at the top, I'm going to be around 30% because they almost have no compression loads. Alright, so let's look at another grid. This grid line for, we can switch from here. Grid line four is a similar story. We have this one here that's just outside the core, taking a fair bit of floods, that one would need to crack it. That's for sure. Let's look at another good line. Green line three is fairly normal. There is nothing much happening. Grid line two is similar to what we were getting with the grid line for it's the internal middle one that needs to be cracked. Our edge columns are generally fine here, okay? So we're quite happy with what we've done. That's unlocked a model. And let's assign, this is an internal load. So assign 30% up to here. And of course we can verify this in detail or we can just approximate it in, on the safe side. These ones are lightly loaded. These ones are heavier loaded, so give them a 50%. And these ones are fairly loaded in compression, so we can give them Rs 70% ratio. And we'll do the same for the one egg grid line four. And we'll also reviews the ones that were along grid line five. If we recall grid line five, we had the ones at the top cracking. So we'll give them a 30%. The ones at the bottom, actually two floors that were cracking, so give them a 70%. Alright, let's run the analysis again and confirm it for one last time. We've got the results. Now let's do one final check on the bending moments. As we can see, the top ones are still cracking, but we've already crack them. They take a bit of moment which is understandable. This one is also cracking, but we've already cracked these ones on elevation five. These ones are fine. And these ones, we've already crack them on a one to the top. And these ones. Alright, so we generally happy that we have cracked cams that actually needed to be cracked. Let's double check and this one. Yep, we have assigned problems. So if you select the member and right-click on it actually pops up the information and you can look at the property modifier. And you can see that we've cracked this one just doing spot checks here. This one is a bit higher as well. Lets show undeformed geometry and do a quick spot check. Yep, we've cracked a k. So generally I'm happy with the fact that we've cracked most of the columns that seems to be cracked already. Now a quick question here that pops to mind is why not just crack all the columns and give all of them 30% only of their stiffness. Since we only designing the core walls to take the lateral loads. The only problem with doing that is if you are doing your gravity design using the information from the same model that you are using to do your lateral load design. If you have two models, one for gravity loads only and one for lateral loads only. And you would argue that in the lateral load model you're actually going to crack all the columns. So they take much less deafness or much less moments and rely on the course only, I would say that's a valid argument. I don't see a problem with that. But for the gravity load, you want to use the actual stiffness of the column so that it takes the correct design moment for you to design the column for because columns are not just designed for compression. Yes, if it's a huge tower column and it has a lot of compression at the bottom. That's a good argument. The compression is going to govern your design. But if it's lightly loaded in compression like the highest two floors, you actually want to take the design moment from a 3D analysis using the correct stiffness of your columns so that you get the correct moments to design for, for the columns. 27. Wind Load Checks Part 3: Now let's start to look at our core walls and how much moments they are taking. Let's switch back our walls. And actually let's, let's switch of all columns for a moment. We don't want to see these joints so you can actually switch them off as well. We can make them invisible. And we can hide our grids. If we click here and I click on hybrid. Okay, so that's much cleaner now. Now let's also see our pier labels so we can go to other assignment, pier label switching on and click OK. We can see that all of these have a pier label, core one, and all of these have a pier label of core two. Ok, let's start to look at we've calculated our north wind and the overturning moment was 511000. If you bring that up quickly again, just for comparison. It was our wind for and we were looking at the overturning moments and we were getting 52 thousand. Alright, so if we switch our peer forces instead of using frames here, we switched to peers. And we look at just the wind north case only and click Apply. Now you'll notice that for peers, M33 is the moment that is along the long direction of the Pier. Now, our north wind is in this direction. So we're looking at the wrong moment here. That's why they are opposite in direction because they're just resisting some twist that is caused by the off-center from the north wind. But we should be looking at M22, Which is That is correct. Now that shows the distribution of the overturning moments between the two towers, between the two core, sorry. So the first core is having a 20,400 kilonewton meter, and the second corps is having 23,600 kilonewton meter. If you add them up, you get around 44 thousand kilonewton meter compared to the full overturning moment here, which is 52. If you work it out as a ratio, that gives us about 85%, which means that our core walls are taking eighty-five percent of the north wind overturning moment, which means that our core walls are going to be designed for only 85% of the lateral stability loads and 15% are taken through the columns and the slabs framing action, which in fact we cannot get rid of any tabs, doesn't matter if you pin all the columns, you will still have positive and negative push and pull on your columns because the slabs run over the columns and essentially just act like a beam. But if you're looking at 80% plus of your forces designed within your core walls. That is generally good enough. All right, so we're happy with our contributions by the core wall and by the framing action. Now. We'll do a quick check on our drifts. Since we are here, we can actually go to diaphragm drifts. And what this is is a ratio of the deflection of one story compared to the one underneath. So if we open up the detailed report and we actually work out at the worst level, which looks like it's Level five here. So if you go to level five, and if we take the square root of the sum of the square of this one and the square of this one. That's going to give us our absolute drift in the y direction and the x-direction. It's the resultant of both of them pretty much, which is 0.001129. Now, this is a ratio, and you can convert this to a percentage. So if u times a 100, that would actually give you 0.11%. And this 0.11%, you can actually translated into also a floor to floor height ratio. So usually we convert back to an absolute number instead of percentage. So you divide by a 100 and you flip it. So one divided by this number gives you a height on eight, 86. Now for wind loads, we limit our internal drifts to usually around the height on 500. So high on 886, actually pretty good and pretty stiff core. So our building is not swaying too much. And the reason that we're limited to hide and 500 is so that it doesn't damage the lifts and finishes in the building. And it doesn't start to create a lot of P delta second-order effects where the building just starts to bend under its own self-weight now. So we're happy with that. Now we also go check if this ratio didn't exceed the limit. The total deflections is pretty much not going to exceed the limits as well. So we only getting a 25 mill deflection at the top of the tower under this is ultimate when we're not even looking at service when. So it's pretty stiff under wind load and there is nothing to worry about there. Now we're going to check for our core walls cracking. So the way we could do that is we'll jump packed or elevation views and switch them to the core elevations. Let's switch on our stresses one more time and let's use our design envelope. This time we're gonna go for a maximum stress because we are looking for tension stress. And again, we're just going to leave it in the vertical direction only. And we are looking for a maximum stress. That is the cracking stress of concrete, which is actually here in the code three-point section 3.1.1, 0.3. It is this value which is the flexural tensile strength of concrete. So it's 0.6 square root fc dash, assuming we're using a 50 MPA concrete back gives us about 4.24 MPA. So we're gonna put the maxim to 4.24 and click Apply. So this is our four-point to four. And anything that is blue, it's basically already cracked. Now, looks like we have these flows here cracking. So we actually need to crack the walls here. The only issue is this probably because of the earthquake, not because the wind, because our design envelope actually has a lot of flood cases. We'll leave that out for now and we'll just check the wind load cases manually. So we're gonna click on the wind load case, click apply. And we'll just, you notice that if we flicker at the bottom, it actually changes the case to the next one here. And you can actually see it changing here as well. Alright, so we're looking for the wind cases seem, arrive. Also another quick way that we could see these results much quicker is if we define a load envelope. So let's add a load envelope for wind. And let's call this an envelope. And let's only use the load cases. Look combination, sorry, that uses wind, which is pretty much starting from Combination three all the way down to combination 25. So we have those in now we could actually use that envelope. So ELS wind envelope and looking at the maximum, only limiting it to 4.24, we can straight away, see the results from our envelope. And our stresses are only in the yellow zone, which is only two MPA. Let's flick through the other core walls. This one here starts to exceed our stress. So this one actually starts to crack here. It goes up to 5.3 MPA, right? Will take note of that one. And grit line d, these ones are fine. This one also starts to crack here. And quit line C is also very similar to greet line d. Ok, so these are the only ones that crack. And what we're gonna do is we can go back to line see grid line d. And the one way with the opening, which was great line two. Alright, so we're going to delete our analysis. And what we're gonna do is we're going to, these ones were the ones that crags, we select them. We go to Shell stiffness modifiers and to crack a wall, we basically need to assign an F12 membrane property. So four walls, they're cracked, their effective stiffness would be reduced to arrange valid. So it depends again on its compression load in the code. You could go up to 40% or as low as 25% and you can interpolate in between. Now for this n star over the gross area, which is basically the compression stress. If you take the fc dash on the other side, it's 0.1 fc dash, which is 0.1 times the concrete grades. Assuming we're using 50 MPA, that is going to leave you with five MPA in compression. We obviously don't have that uniform compression on the walls. So it's this value over here. And because of that, we can apply twenty-five percent only of our effective stiffness. So we'll use our F12 by 25% for these ones. And also the ones on gridlines C and D was this one here. Now let's redo our analysis and see if other worlds started to crack because it's a little bit tricky that when you reduce the stiffness of one wall, a becomes less stiff. So obviously this load has to go to somewhere else that's more stiff. So somewhere that wasn't cracking previously might started crying now because it will start attracting more load. And you might end up in a circle of a few rounds of rerunning and iterating until he actually reached the bottom of it. And, you know, reach a case where you have cracked all the wars that cracked and the ones that are not cracked don't start cracking now. So that's what we need to check now. So our analysis finished running. Let's switch on our stresses one last time. Yep, that one that cracks till cracks the other ones don't crack, which is good news. Good news. All right. It looks like we've reached the convergent point fairly quickly. And that means we don't need to spend any more time on cracking these walls. So now we have the correct stiffness model. Then we're happy with the performance of the building on the wind. We're happy with how the wind loads are distributed between the cores and the columns. And we are good to go for designing our walls are stability walls using these loads. Now that we have refined our analysis to the point where we happy with. And now we're going to start looking at our earthquake loads to get them up to the same level of confidence that we have with our wind loads before we start looking into designing and detailing our core walls and headers. All right, we'll see you in the next lecture for the earthquake design. 28. Static Earthquake Part 1: Hello everyone. Today we'll be looking at static earthquake analysis. We want to verify the analysis results. For instance, we are getting from E tabs. And then we'll be looking at the results of this analysis and what it means to design pretty much. The first thing that we need to verify in our analysis is the mass of the building that was used in the analysis. And to do that, we can just quickly work out based on the age of the flow plate and the slab thickness, the super dead loads that we assigned in the building, and the live loads where we assign as well. We can work out roughly how much is the mass of each floor, and then we can see how much ETags have actually worked it out to be. So let's start with that. The aim of our flow plate is roughly about 11926 meter square. And we have defined 200 thick plate. So that is equivalent to 4.8 GPA of self-weight. And we've assigned an office shall load. And if you recall, if we go back to our shell load sets, our office loads are one for the superimposed dead load. So one plus 4.8, and that gives us 5.8 GPA for the dead load component of the flow. And we've assigned 3K PA live load. But also, if you recall, in our mass assignments because this is for earthquake, we actually assigned, sorry, we actually assigned a factor of 0.3 to live load because that's basically the self-weight of the seismic weight of the building that we should use in the analysis according to AS 170.4. So 0.3 times three, that gives us about 0.9 KPI for the live load. And then if we add on to that, that dead load and live load times the area that we just worked it out, comes to about 12,900 kilonewton. That load, just the flow plate. And if we add in the perimeter line load that we applied on the building, that comes to about 355 kilonewton as well. 0 adding all of them up, comes up to about 3,300 kilometers in. Now to see how much ETags work it out, we could go to this play tables. And in there, we can go to other load definitions. Let's go to the master data, and let's look at the mass by story and the mass by diaphragm. Now, ETags uses the mass by story to work out the earthquake. And the mass diaphragm is whatever that is assigned to the diaphragm. So it's defined by you. And this is a bit of important distinction to be made here that a mass by story includes the column load in that story, but a mass by a diaphragm if he didn't assign the column and the wall into the diaphragm. That means it's not going to be included in the mass. So if you actually open up these two tables, you can see that the mass by diaphragm is about 13,800 kilonewton. And the mass boy's story, it's actually 14,700 and about there. So the mass by story is heavier because it takes into account the self-weight of the columns and the walls, which is what we want. Because when you work in the seismic weight of the building, you should include the self-weight of the walls and the columns. And depending how big are you co-owned and walls, they could make a difference. In this case, they may a difference of about 100 per floor, and that actually works out to be about 7.5% of the flow load because we have a big flow plate. What if for some reason we have a smaller building with only smaller area, flow plate area, the columns weight is actually gonna be a big percentage of the building. Or if this was a super high-rise building and the columns were huge. We're talking a meter by meter columns that is going to add lot of weight of the building. So just be careful of that. Anyhow, if we go to the diaphragm load just to compare what we got, we got about 13,300 ETags, work that out to be about 13,800. Actually this is a mass. So if you actually convert the kilo-Newton eight comes very, very close. So I'm happy with the flow plate masses that it hasn't worked out. And I'm happy with the story masses that Egypt had, had worked out. And we could use that to start checking the analysis results. Quick way to check the results is to actually go to this play story response plots. In here. We could go to O2 lateral loads, two diaphragms. And we can see we have our earthquake static load cases, and we have our wind static load cases. So let's look at the earthquake load case. If we go to detailed report over here, we could actually go to a second page and we can have a detailed table of these forces that ETFs have applied to each floor in the x-direction because we're actually looking at the earthquake in the x-direction. Now, if we switch that to the y direction, we go to the table. Again, we could see our earthquake and wider action and they should perfectly match because this is a static load cases, doesn't it depend on the mass, basically in two directions. You still have the same mass of the building. It's not like wind way depends on the width of exposure of the wind on the building. Now, if you want to look at the total shear force at the bottom of the building, which is what we want to verify. First, we should go to something called the storey shears. And once you're in the storey shear is make sure you switch to the earthquake static load case. And you could actually open the detailed report one more time. And if you go to a second page, you can see the base shear force is 5,675. So that's what e-types had worked out. Let's verify that by the code first. And to do that, we're going to open our tables one more time. And we are going to open the table that has the mass information, which is the one that we selected previously. And once that opens, we can go to Mass by story. And if you actually click on File, Export table to exile. Alright, so we've got our table in Excel now and we could add up the total mass of all the stories. And if we actually multiplied by 9.81, which G divided by 100 to make it in kilonewton, we get about thirteen thousand, one hundred and thirty two thousand kilonewton and 763. Now that is the total mass of the building and it's identical in the x and the y direction. Now with this load, while we could do is we could start looking at the equation from our design code. So if we go to a S11 70.4, and if we jump on to page 38, section 6.2, for the horizontal equivalent static force, the earthquake base shear force will see the equation that we should use. And in fact, e-Types is using to workout the static base shear force. We look at this one over here, which is basically these ones after you open them up. Let's start from the left hand side. We've got our importance factor, which is 1.00. We've got our hazard factor, which is 0.08. And this C H t1 factor is in fact a factor that depends on the soil class and depends on the natural period of the building. So if we go down next page, if we jump into the natural period of the structure, this is an empirical equation that AS1 and 70.4 commands for calculating the period of the structure, which we have seen earlier when we were defining our static earthquake load case on E tabs. Because we need to input this K T factor into e-Types. Now with that in mind, our Katy was 0.05. because we're using a core wall system and our height of the building is in fact 34.9 meters. So if you work it out, we get a fundamental period of 0.897 seconds. Now, if we go to the next page, section 6.4, we have a table here that depending on the period that we just worked out, which was almost 0.9. And depending on the soil that the building is founded on, which is assumed to be class C. Over here. We are going to be getting a factor that is about 1.39. So if we plot in, if you take this value and put it back in our equation, we got 1.39 here or SBN mu factors. We took it as limited ductile, which is 0.707 for SB and two for mu. And if you notice once we, we add them into the equation here, we actually reducing our base shear force. And then the last value that we need to add to the equation is the self-weight of the building, which we just took from e-Types after we have verified the mass calculations from E tabs. And that was 132,763 kilometer. So in the end, if you multiply all of these values together, you will get about 5,683 kilonewton. And if we jump back on our E-types for a second and go back to our detailed results. We'll see that we're getting 5,673, which is very, very close. If we switch to the x-y direction, should be getting exactly the same results just in a different direction, which is what we are getting over here. And that takes the blocks of checking the earthquake base shear force that Etypes had worked out. Now the last thing is the distribution of this force on each floor, which shows actually the first thing that we looked at, which was the auto lateral load two diaphragms. If you look here, we'll see that this load increase in terms of the building height. If we go to our code on Section 6.3, it will actually give us the equation that distributes our base shear force with this equation is exactly the same as the one that we just worked out. 5,683, that's our base shear force. This wi is the weight of the story that he calculating. The force for an edge EI is the height of that story. And it, it's an exponent that is called K phi, which can be interpolated between T1 of 0.05. and T 2.5. because our T1 was 1.4. So if we work it out in between, we get a fixed value of k and n is the number of levels of the structure. So once you plot in this numbers in here, that is the total weight of each story times the height of each story to the factor that we work out. If you add them all together for all the stories that will give you the denominator. And if you work it out for each floor, you should be getting a force distribution that looks like this because it's dependent on the weight of the floor, as well as on its height. The higher the building, the higher the component you should be getting. And also the higher the mass of the flow, the higher the force that you should be getting. So if you actually draw a line here, it's all almost same because the same mass, but when it gets the higher, highest flow, we define the heavier loads for the roof because of the plant and because of the screening that we expect will be on the roof. So we see that the line doesn't line up with the roof. The roof is actually heavier than normal increase in the floor. So that looks alright. We verify that you can go ahead and work it out on a spreadsheet. But I myself, I'm happy with this result so far. And I'm ready to start looking at the design stresses and design forces to actually progress with my design for the walls. 29. Static Earthquake Part 2: Now let's start having a look at those design earthquake forces that we just verify in the previous lecture. The first thing that we should be looking at is in fact, how much are these core rules taking and how much is taken through the framing action of the slab and the columns. Typically in buildings you will have a framing action and you cannot escape from it too much because you have the slabs and the columns connected and they're not pin, they have reinforcement that is most often developed. For that, it's quite common that you'll actually have somewhere between 95% to 75% of your overturning moments taken by your core walls and the rest is actually distributed within the building through the framing action. To actually have a look in quantify how much that isn't new building. First you gotta go and have a look at how much is your overturning moments. So let's go to our stories, ponds, plots, and let's switch to overturning moments. And let's look for the earthquake static in the x-direction. And as you can see at the bottom here, it's 145 thousand. And in the y direction, It's also 145 thousand. We could go here and we can go to our peer forces display, and we can switch our load case to earthquake static. And we can just leave it as step one. And let's look at our moment. So if you click apply, if we, if we go closer to the value and new right-click, it should open up diagram 4s for you. And you can see here that in our earthquake static, if we switched to maximum and minimum, we can see here that we actually have a bar 100000300 overturning moment. And if we look at the other one and we make it maximum and minimum as well, we'll see that it's also taken about 1000000200. So if we add these two values together, we have 2500 kilonewton meter as our overturning moment by the two cores. And if you remember from here, we actually had 145 thousand. So this force go, we were actually looking at the wrong load case because earthquake x was actually an earth quake force that's in the x direction. So it should be causing a major moment on the core world. But we should be looking at earthquake in the y direction, which causes a moment on the minor axis of each course. So we're looking at the minor axis and we will looking at the earthquake acts, which doesn't make sense. So make sure to switch on, that's a good lesson. Make sure to switch on to the earthquake and the wider action and apply that to see the forces. And once more, right-click on each one of them. For the first one we are getting 62,840 kilonewton meter. And for the second core wall, we're actually getting 48,680 kilonewton that adds up together to 111 thousand. And if you can remember, or total was 145. So 111 out of 145, there's roughly a 76% of the overturning moment. And the rest is actually taken whether framing action of the building for look in the other direction. Make sure to switch to the earthquake x in this case. And we can see here that we have 85 thousand on this first core wall, and we have 87,500 on the second core wall, which gives us 172 thousand kilonewton meter. So the total of the moment in this direction is actually bigger than the applied moment. And that is because of the eccentricity. Some of the steps are actually the ones where we have eccentricity in the building, in the x and the y-direction. So because it is centricity, you might end up with actually having a bit of a bigger moment in some cases like this one. But that means we are taken 100% of our earthquake overturning in this direction, which is the x direction. And we've taken about 76% of the overturning in the minor direction, which I would say is good enough as a result, if you would want to increase it, you want to make sure that you've actually assigned edge releases between the Slavs and the core wall. So they don't take moments in between. And you might actually go the extra cores and just pin all the columns are the columns don't take any moments from the slab. It's purely just axial force. Currently we have them as fixed because we want to see how much moments is going into the columns from the slabs under the gravity load. But if you, we want to increase the moments on the core, you can save as the model being all the columns. And you'll start to notice that you're moments in the core walls have actually increased. So let's do that. So let's save as this model and do a quick check. Let's call that killed columns. Now, let's switch it back to neutral. Show our objects. Actually, I think we've hidden them from display options. So let's go to set display option. Switch on our columns from here and switch off our walls. Let's switch off the openings as well. Ng-click apply. Alright, so we have our columns here. What we can do then is you could actually select both of them. And we go to Assign frame releases. And we could put major and minor releases on the top and the bottom. So effectively we pinning them in two directions at the top and the bottom. Now, be careful because if you actually pin the bottom of a column that's on a roller, it's going to give you instability. We are going to select the lowest floor of columns and we're actually going to. Only release it at the top, not at the bottom, like what you can see here. So the model works fine. Now, let's run the analysis and see how much is our core Wall taking now. The analysis is still running in the background, but I probably should mention that pinning the columns is usually one of the reasons that you might get instability in your model. In some situations where you have a double height columns and you pin them at the middle, that obviously causes instability. So be careful when you select all the columns and pin them all. Just be mindful. If there is any column that actually goes double height, for example, if this was a void in the slab, these columns actually go to floors without restrain here. So if I pin them, dislocation, I mean, the floor above is pinned here and the floor under is pinned here at this level and there is no slab. That is a very big reason why you might be getting instability errors in your model. Let's check to see if we actually had any instability areas. Nope, we have eigenvalue, negative eigenvalue of 0, which means our building is stable. In fact. Now let's switch back our core walls. And this time, our analysis shouldn't change because we are only pin the column. We didn't change anything related to the mass or the height of the building. So if we go back and switch our moments M22 for the earthquake, why static? And start to look at our moment values now, we'll see that here we have 68,314. And for the other one, we're getting 63,557. Now we are getting a 131 overturning moment compared to 140, which gives us 145 was less. Double-check, was 145 years. So we are getting about 91% of our overturning moment in the core walls now. But remember our columns are pinned. So I'm not going to use this model to design my columns for gravity loads because it's not giving me realistic bending moments. And you have to be careful in design columns to use the correct bending moments from your elastic analysis. So this model, I'm only going to use it to design my core walls for my stability forces because my columns are pinned. All of my load, most of my load, almost 92% or 91% is going into a core walls. So I have the confidence that my load is in there, in the core walls. Now I can start to look at the stresses and the forces. And say, Okay, that is actually what I want to design for. 30. Static Earthquake Part 3: Alright, let's switch back to neutral view. And what we're gonna do now is we're going to start to check the walls that crack. And we need to assign them with the correct stiffness that they have cracked. So let's go to the elevation view. And that is the benefit of having the cores modeled at grids. You can actually quickly and easily open the elevation. We have to check the cracking of the cores with mu equal to one, which means it's an inductor L earthquake load case. So we didn't define the non ductile static load case, we only have to open it to check our definition. We had mu of two and SP of 0.707, which is in fact that afflicted limited the cloud. So to quickly do this without having to rerun the analysis, we can actually define a load combination. And we could call this combination earthquake static eggs. And we can call it an undirected. So we can select our earthquake static eggs. And we could in fact just multiply it by two because none ductile, it is a simple scalar multiplier of two compared to the limited tactile load case. And we'll do the same in the y direction. And now what we gotta do is we're going to start defining our load cases for earthquake. So this one here which we had it with the earthquake static, that was actually a design load case and that was using the earthquake static. We gotta make copies of all of these cases that are using the static load case. And we gotta make them with the non ductile static load case. And then we can create an envelope of that. So I'm gonna go ahead and create a copy of these and we'll go from there. So I've added all the load combinations with ductile earthquake load case, and these are from 3942. So what I'm gonna do now is it's exactly the same as the load cases from 2730. By the way, it's just that it's using the non-doctors earthquake load combination that we just added. What I'm gonna do now is I'm gonna add an envelope load case. And I'm gonna call this quake static non-doctors combos envelope. And this is the load case that I'm going to pretty much used to check the stresses in the world for cracking. So I'm going to add the load cases starting from 39, all the way. 42. Alright, so we added all the other cases from 399840484141, eight forty two hundred forty two a and this envelope case. Now let's click OK and let's save this model. To start looking at the stresses here we're gonna go to our display shelf stress forces. And we're gonna go to the load combination, the envelope load combination that we just created. That's the one over here. And let's look at first we want to see our tension forces. So tension and ETags is. Positive value. So we're looking at the maximum positive value. We switched this too shall stresses. And we are looking at the S22 stress, which is the vertical stress on the wall. And let's switch this as well to the maximum stress on any face. Let's show a fill but set transparency to 50%. And we'll set our maximum tensions trusts the cracking stress of concrete, which is 0.6 square root fc dash. If we assume we're using a 50 MPA of concrete, that is basically going six times by 50 MPA to the square root of that, which is 4.24. Click Apply. Yep, sometimes that happens from E tabs. And we are definitely going to crack. Let's actually go to three the just to get an idea of the few different load cases that we have. Let's go back to the ultimate envelope that we were looking at. And it seems reasonable that we have most of our core walls cracking given the size of the building and the amount of overturning moment on these walls. So with that being said, it's actually quite easy to go back into the elevations now. And what we're gonna do is we're going to mark the wars that crack. These ones, all of them cracked. Let's assign them to a group. A group is a group that you want to be able to select and assign things to later on without like marking them on highlighting. So let's add a new group and let's call this core walls earthquake static load case. And let's leave it as blue colour. Alright, so we have it here. Now let's select Add to Group, and let's add these walls to that group. That's switchback house dresses on. And now let's go to the next. Great. So the way you can navigate the next grade is you could select it from hearing click apply, but you could also use these buttons if you select up, that basically switches it to the next one. Actually, I feel the stresses are a little bit too dark, so let's reduce the transparency here. Yeah, okay, that's better. So we have these ones cracking here as well. This side doesn't crack, but over all the edges crack, so that means they cracked me. Let's assign them to our group of cracking switchback with stresses on. Let's go to the next elevation. Same thing. Select them. Now we don't have to click apply to the group and then switch on. We can actually just keep selecting and rotating our elevations. This whole thing cracks. Rotate OK, in the edges. Craig, over here, they exceed the stresses. These ones, the whole thing crashed. Again. The whole thing crack. These ones, crack, this one's cracked. So the whole thing again here, it's fair to say that this one cracked. But this one actually I'm gonna say this is not correct. This is because of just localized only because the gravity loads most probably. So I don't need to crack this, but the top one looks like it's cracked. And as gooseneck salvation, the ends of the wall or cracking intention over here. So I'm gonna select the whole thing and say it's cracked. That whole thing is cracked. And then we're done with the elevations for the course. And now we can add them to our Cracked core walls and click apply. What I'm gonna do now is I'm going to erase the analysis of the model. I'm going to save this model as because I'm going to assign the stiffness. So I'm going to call this R3. And I'm going to explain what happened here, which is pinned columns and crack core walls with earthquake. Study. Non-doctors. I don't need to put an undercoat because check cracking to undock towel anyway. So it's to the earthquake static load case, cracked walls. So I'm gonna save it as a quick way to get back to the wars that we selected is to go to select and select by groups. And let's select our Cracked cores. And you can see here we have 423 shells, which is the ones that we just select the previously. Now what we could do is we could actually define a new wall section for the cracked walls. So we were using to a 100 and thick walls. We can add a copy of that and we can call them 200 thick walls. Well, let's call them crack four walls. Once they crack, according to a study 600, you give them a reduced stiffness based on how much compression they have. And most of the walls, I would say there are somewhere between 0.1 fc dash in terms of compression is very difficult that you'll have wars was such a heavy compression that they crack. So I'm gonna just go with the lowest value here, which is 25% of my stiffness. So I'm gonna go to modify the property for this wall type. And the way that he reduced the stiffness for a wall is through its membrane forces, not the bending stiffness. Bending stiffness is out of plane bending of the wall. But in plane, which is what is used to resist those loads is actually the membrane forces. So I'm going to assign 0.25 to all my membrane forces here. But the key one is F12 actually. And I'm going to click OK. And I'm going to click okay, so now I have a new world type. I have those wall selected. So let's give these walls, that wall type. So let's go to All section and assign this to a 100 dash, one crack to them and click apply. If I click on any of them, I can see that I have 200 dash one section assigned to them. Or I could also from my display options, instead of viewing by objects, I can view by section properties. And that basically means that if I go to 3D now and I rotate around, I'll see different colors have different sections. So these are the only ones that dealing crack and that is expected for static earthquake load force because it's fairly conservative MP increases with the building height. So we have really big stresses if we design to the static load case. And not to mention also the amount of work we had to do to define our load combinations. Which in fact, you could just save this file as a template and you could import it to create new eat as far in the future. So you don't have to spend the time and defining all of these load combinations. But nonetheless, if you, if you're using the static load case to design, yes, it's going to save you a bit of time in terms of running the analysis model. But at the end of the day, it's fairly conservative. And that's what we're going to see when we start looking at the dynamic load case and actually compare the two cases together. 31. Static Earthquake Part 4: So we've amended the stiffness of the cracked walls. Now the last thing that we need to check is actually our lateral drifts of the building. The earthquake code, regardless of your design category, it always limits you to 1.5% of cystoid drift. So if you work out, this ratio is a number 1.5 bar by 100. That in fact gives you a number that is 0.015. And this is re-shift. It's like a percentage of the lateral drift, which is the horizontal movement of the floor relative to the height of the building. So it's a ratio of how much the floor above moved horizontally compared to the floor below, and compare it to the floor to floor height. If that value is too high, what starts to happen is that you have your compression load coming down the building now it's offset a lot from its original position. And that upset source to introduce something called the secondary moments on the column, which is a P delta effect. So essentially if you have a very big drift in your building, what it means is that you are getting a huge secondary forces that you need to consider in your design. And for that purpose, if you actually convert this 1.5% into a ratio of the height, the lateral drift. You could do that by using reversing it. So you divide a 100 by 1.5, that gives you a high on 66. Lateral drift. Usually that valley is limited in the wind designed to only height on 500. Because it's a frequent design situation that the wind is gonna blow on the building pretty commonly almost every day with the earthquake. It only happens every few years. So a 166 is actually a lot of drifts already if you think about it. So most of the time you want to limit your earthquake drifts to much higher than that. Practically, you should limit it to hide on 250 or high 300s. Just as a good rule of thumb, to avoid having big P Delta Forces and effects into your building. So you don't need to worry about that later on. If he getting very big drifts that are less than height on 250, you might need to start to switch on your P delta analysis in the model. And we'll do a lecture on that to actually quantify these forces and take them into account. Now let's see how much our drifts is. So let's good story response. We actually need to close all of this. I have too many things open now. And I need to rerun the analysis because we've just crack those members. So our analysis done, and now we're going to jump into our story plot responses to see our drifts. The way you can see that is we jump into diaphragm drifts. And we'll switch to the the load case that we're looking at. So let's look at them on the Cloud load case. In the x direction, we are getting 0.0.0, 6-7. So if we inverse this value, which is one divided by 0.006769, we get a height on 150, which is a bit of HIV drift value. And it gives us an indicator that probably we'll have big effects in terms of P Delta. And they might actually start to influence some of the columns design because the building deflects too much. And also on the course, that means we need to consider that effects into the course as well because that will put additional moments on the course. In the y-direction. We are getting 0.026. So if we inverse that again, one divided 0.026493, we are getting higher on 37, which in fact means we exceeded the drift lemon on the building. And our lateral stability system is insufficient to resist these forces. Now, when we reach this point, we pretty clear that we need to do something about it to strengthen our building laterally. So what we might need to start to look at doing is perhaps adding some shear wall somewhere else in the building to help with the stiffness. Or we can start to look at thickening the walls to add increased stiffness into the building. We could make these walls 300 thick instead of 200. And we could revisit again how we could do if it's still not working in terms of drift, we could start to look at adding headers to link the two chords together there so that they are more stiff. But either way, the preliminary results that we're getting here based on the static earthquake analysis, is that these two cores are actually insufficient to meet the drift limit requirements. Now I'm checking the drift using the non ductile load case because the earthquake code requires you to check the drift using this and on the Cloud Load k. So if you actually go to section 6.7 for the storied drift determination, it states that you're drift should be done using new whatever drift can be increased up by mu over SB. Which basically means that if you're using limited the tile results to look at the drifts, you need to increase your drift by the scalar component that you reduce the force for, which is exactly the same as just using the tactile shear force results. So with that in mind, well, we can do now is in this case, try to increase our core wall thickness to 300 and see if that starts to solve our problem. Let's unlock our model. Unless you go to our world properties. And let's change this world type. Let's call it level you 300. And let's increase it to 50 MPA. Actually increasing the concrete grade helps with stiffness because you have a higher concrete young modulus. We don't have a 50 MPA. So what we can do is we can add a new material from here and goes in New Zealand, concrete. And add our 50 MPA concrete grade. Let's call this just 50 MPA. And we will update our Young's modulus of elasticity to match AS 3600 and make sure it's a 50 MPA. Okay? Okay, and let's use the 50 MPA. Let's increase our thickness to 300. And let's make sure the modifiers that was on cracked wall. Now let's go to our cracked wall and do exactly the same thing. We'll call this 300. And we'll call it 50 MPA wall. And our modifiers are cracked. That's correct. Let's click OK. And now let's try to run the model and see how drifts are going to perform that. Our analysis is done here and now we can jump into our story plot responses. We'll see that our drifts now has actually reduced to just 0.018. And if we inverse this value, we will be getting about higher on 53, which still again exceeds our limit. So we have to do something about it. The next step that we can start to do is to add headers between the two cores to tie the two cores together. So they act as one big composite core together instead of two individuals, smaller cores. The way to do that, we're gonna unlock all models again and we're gonna go to the elevation. Let's switch on the grids here. Yeah, let's go to this elevation a and add the header there. Let's model it on plan first, let's add a wall. And we are going to select the 350 MPA cracked and we are going to draw it. Actually you're gonna switch on to modelling of all stories. And let's draw one here. And let's draw another one here. Okay, we have to add in the reference planes. So let's go to draw reference plane for our headers, like what we've done previously when we were modelling our cores. Let's draw the reference plane at 2.5 meter head height. And we're drawing this on the main building grids. Let's draw it here. Yeah. And every flow. If you can notice that reference plane starts coming up now. And what we're gonna do is that we are going to select our wall that we just added. And we're going to go to the divide shelled command and divide it with the grids. So we can select these ones. These are the ones who go into delete and let's lead them. So we only have the headers now. And to improve the accuracy of the analysis, what I would do is I would divide the shells the points where they need the header. The way to do that is you go to the Device option and you choose selected joint on the edge of the shell. So it divides like bad. That gives is generally better meshing results. And what we did here, we're going to do exactly the same at the other side of the core, which was great line C. So we're gonna go to elevation c now. And we select now we don't need that, save our work. We don't need to draw in our reference plane again because it's already drawn for the entire building. We can select them again. We can divide them, the grids. We can delete the opening ones. And again, we can mesh the core wall at the location though intersects. You select the shell that you want to cut and the joint, and then go to selected joint object on the edge and click apply. So we have our shall cut in here. All right, that sounds good. Now, one last thing we need to do is let's select all of our walls now. Select object type, select the walls, and let's assign the meshing to them so we can go to Shell will auto mesh option and let's match all of them. And let's run the analysis now and see how that is going to improve our results now. Now we have our results and analysis is done. Let's jump into story responses to see how we're doing. Now we are getting 0.0067. If we inverse that value, we are getting high on 150, which meets the limit requirements from the code, but it's a bit too high. So in this case, what I would, what I would have to do is switch on my p delta analysis to actually make sure that I'm taking any secondary order effects into my analysis. And the way that I could do that is by going into p delta options. Actually I first have to unlock the analysis. I go to define p delta options, and I'm going to choose it based on loads. Now the ultimate loads that I'm having here is G, which is dead load than superimposed dead load plus my Q, which is my live load. That is only 0.3 because earthquake is governing right now. And then my earthquake static. And I'm using a factor of two. Same for my earthquakes static y also using a factor of two. Now why I am using a factor of two because the building is going to deflect according to a factor of two, not a factor of one. Because we define this static load case to be limited tactile, but the building is first kind of flagged as none tactile. So these are the loads that the building is deflecting a lot under. And these are the loads that e-Types is going to use to run mine none tactile, sorry, non-linear P delta analysis. And then run the analysis usually it takes a longer time than usual. So if that happens with either is expected because it's very iterative process that takes a bit of time. So don't be weighted, that happens. Okay, so it took about three to four minutes here on my PC, but looks like the analysis is done. Now let's jump back and check our drifts. In fact, our drifts have increased with the P delta that is expected because of the secondary moments that has to be resisted by the Corps to stabilize the building. So previously it was 0.05. 6-7. Now it's 0.0072, which gives us now a hide on 138 compared to previously height on 150,138 is strictly within the limit of the code, which is the 1.5%. So we actually pause the lateral drift check now. But we needed to thicken our walls to be 300 feet. And we needed to add those headers at every floor to link the two cores together so they act as one big core for the building that was under the static earthquake. It will be very interesting to see what results we are going to end up with if we use the dynamic analysis of the earthquake, which we're gonna do in the next lecture. 32. Dynamic Earthquake Design: Hello again. Now let's start checking the design to the dynamic earthquake instead of the static one. And to do that, I'm going to switch back to an older version of the building, which is the R2 version, where I had my columns pin. Actually I could go to the earlier version, which is when I had my columns actually fixed. Alright, so the first thing that we get a check for the dynamic analysis first, we verified the masses already in the building when we were doing our static analysis. So look back on that video. If you haven't checked them, mass of the building yet. The other thing that is unique to the modal analysis is actually the modes of the building. So to verify that we have analyzed enough modes of the structure to include all of the building modes in our dynamic analysis. We can go to this play tables. And this time, we could go to structure output model information. We can look at the participating mass ratios and the modal direction factors and the participation factors. And let's click OK. So a table would come up. And what we can do is we can switch to the participating mass rages first. We can see that the first period was predominantly a rotation about Z fact Z0. So if you look at the axis over here, UX is a building that is oscillating or vibrating in the x direction. Over here, which is in this direction, UY is building this vibrating along the y-direction. Uci is a building that's vibrating up and down. And then the R is the rotation. So RX is a building that is basically twisting in the x-direction. Our y is a building that is rotating in the y direction and z is a building that is oscillating in torsion direction around the plan. So our first mode, these numbers are actually wait for percentage. So you can see that the first period is mostly waited in the rotation, which is the torsion social oscillation of the building. So we can expect that our first model is gonna be a torsional mode in the y axis because that's where the weak axes of the core is. Our second mode was actually predominately just is oscillation in the y direction with a little bit of torsion. Again, our third mode was just oscillation in the x direction, and so on and so forth. Now, if you switch on to actually look at the sum of these weightage, we can see that the increases with every mode until the last mode they reach. How much in total that was accumulated with all analysis modes that we've done. So the code specifies at least a 90% of the modes are considered. And we can see here that we've achieved 98% in the X, 97% in the y direction. And the other important one is to torsion. We have actually achieved the ninety-nine percent. Torsional direction. For me I like to achieve at least 95% in these three. It's fairly easy to achieve that with not so many modes. So might as well achieved a higher percentage to actually have confidence that you have converged enough modes into your analysis for the dynamic earthquake forces that's going to be done later on. Alright. So now we can start to look at the overturning moments at the base. Like what we've done with the static earthquake force. We can go to this play, story response plots. And we can look at the overturning moments. This time we're switching on or earthquake dynamic load case. And we're looking at the limited that file load case, which is this one. As we can see here, we are getting about 93,300 overturning moment. If you actually compare that with the static load case that we were looking at earlier. Again, for limited tactile, we're getting 100. Sorry, this dynamic load case til the static, which was this one, we are getting a 145 and with a dynamic we are getting only 90. And the reason that is is that instead of actually looking at the moment, if we look at the storey shear, is, if we look at the static force, we actually have bigger shear forces applied higher in the building. But if we look at the dynamic load case, we actually have the opposite. We have a little bit of high load up here, but then the loads are fairly small within the middle height of the building, and they increase again at the base of the building. The width of this step is how much shear force is applied at each floor. So you can see here it's quite small. It's a bit high on the top because of the weight of the building that we have. I mean, heavier roof that we have. And it reduces at the bottom. And because of this distribution, the shear forces on the building that actually reduces your moment because that brings your action force instead of being up here, for example, you bring it down here close to the ground, so that reduces your overturning moment. So we end up with 90, something, 1000 instead of 145. Now that is a big, big difference in the analysis. And it actually reflects how the building is going to behave. And the code recognizes that they could always says that if you can do a dynamic analysis, do a dynamic analysis, you can always choose a higher design level. Instead of using the static, just because it gives you less force, doesn't mean it's actually conservative. It's actually more realistic because it considers the modes of the building and how's the building going to vibrate when the dynamic earthquake waves arrives at the building occasion. So we've had a look at our overturning moments and our shear forces. We have can actually compare them so we can go to the table. And instead of looking at the model results, let's actually look at the base reaction. Let's make sure we select the load cases that we want to look at. We want to look at the dynamic limited octal and compare it to the static load case in the x-direction and the static load case in the Y direction. Okay, so with the static, we're getting 5,600 base share in both directions. With a dynamic, we're getting 5 thousand the x direction and 3,200 in the y direction. And the reason that with dynamic we have bigger shear force in the x-direction is because the courts are more stuff in this direction. So they actually can resist the vibration better and more stiff building will attract more earthquake force. So that direction is more stiff, it attracts more shear force. That direction is more flexible because it's the weaker axis of the cores. So it actually makes sense that it's attracting less shear force in that direction. Now, in Australian standard, we don't need to modify any of the parameters for the dynamic earthquake analysis. But in other codes like the American code for example, you will need to scale up you dynamic analysis so you at least achieved the same base shear force as your static analysis. That is required in some codes. It is not required in your code as far as I know. It's not required in the Austrian standards as well. So once we have satisfied the number of modal mass participation, which we just checked was 98% or thereabout. We're good to go with the analysis and we don't need to modify it any further than that, and we can just use that straight away to design. Now the second thing that we need to do now is to start looking at the core walls and start cracking them like what we did with the static load case. Only this time we go to shells trusses. Combinations is much, much simpler because in fact we only have one load combination, which is this one. G plus 0.3 q plus two dynamic earthquake none ductile system. We can look at the maximum stress. The maximum stresses in the S22 direction. And again, that was 0.6 times the square root of 50 MPA. Now we didn't need all of these load combinations because the dynamic analysis from ETags actually considers centricity is on each member when it does the analysis. And there is also give you ease and envelope of the different modes that were applied on the building. And for that reason, we don't need to do those earthquake combinations with 0.3 EQ plus and minus and things like that. If you recall, when we defined our dynamic load case, which I'm going to open up right now. We included this a combination type and absolute combination, which means it combines 1, 100% from one direction and 30% from the secondary direction. And it reports the overall result to you. And We've actually included a 10% eccentricity in our dynamic analysis as well. So it envelopes all these results and it gives you an output of only one result. So it's actually faster to analyze an E tabs then the static one, believe it or not. Think we're looking at their own closed case here, should be looking at this one. Okay. So like we did with the static, these ones look like they crack. So what I'm going to do is I'm going to select them. And I'm going to assign them to a group. We're gonna create a new group and call it brag, four walls. But this is the dynamic one. All right, and let's just add them to the group. Let's switch on the elevations and see the other ones. This one doesn't crack only probably just the lowest floors. This one over here is cracking. This one similarly, it only cracks down here. This one, the whole thing is cracking. This one again, I would say the whole thing is cracking. Same here. This one is cracking only up to here. Actually that was already selected. Those ones don't crack. And those ones also don't crack. Those ones are very, very peaks trusted the corners and it's very close to our four-point three. I think it's fair to say that they don't crack as well. Alright, next one. These ones don't crack. I bet one cracks here K That one cracks, that one doesn't crack. That is good. Doesn't crack. Now on cracks. Okay. Next one. We're looking at the whole thing cracking here except perhaps this one, No, this one now. These ones No. No, no. Actually these ones crack here. There are left-hand side. Okay. We'll leave them as cracking. Next one. Again, we have bit of cracking in the end there, so we have to crack the whole thing. All right, so these are the ones that crack that assign them to our group. And let's raise our analysis. And let's like the ones that actually cracked. So how we select the group and we go and define our wall, Section four cracked wall, so we had a copy. What we need to do is go to the modifier and assign twenty-five percent stiffness reduction. And let's then apply this wall section to the ones that we have selected because they cracked. Okay, let's rerun the analysis now. So now we've identified the ones that cracked. The next thing that we need to seize actually need to see how much is the contribution of the framing action versus the contribution by our core walls, which is what we're going to look at in a minute. Ok, so my analysis is done now and I'm going to switch to my 3D view and look at my overturning moments that's taken by my core. So I'm going to go to the dynamic load case for limited as are non ductile. Actually, we can look at either one. Let's look at the limited tactile for now, and let's look at the M22 for the peers. And if we click here, we can see that this one is taken about 9,300, overturning moment. And this one is taken about 5,750. So there's total is 15 thousand. If I go here and I look for the earthquake, clemency, ductile overturning moment. I could see that my total overturning and the bays about the x-direction is actually 18,300. And my corner taken 15 thousand. So 15 thousand out of 18 thousand is about 84%, which I think is pretty good. If you want to put more loads on the core and for the consistency of what we've done with the static analysis. Let's do that so that we are consistent in terms of the forces and the drift that we are going to check soon. So let's Save As this file. And let's put it as r four. And this is the best offers project with pinned columns for the ductile and for the dynamic analysis. Again, like what we've done, we are going to toggle on columns and switch off our walls and openings. We can select all of our columns, go to Assign frame release, and we assign top and bottom. Click apply. And then we want to make sure that the lowest floor columns don't have releases at the base to avoid instability problems in the analysis. And we are going to rerun our analysis now. So my analysis is done, and now I'm gonna switch back on to see my walls and switch off the columns. And I'll look at the peer forces again to double-check How much are my course taking now? So the first core now is taking 8,984 kilonewton. And my second core is taking. 5,825, that adds up to 14,800 overturning moment. And let's check how much was my design. Tricky part is that my design moment actually reduced. Previously it was 18 thousand because I had the columns fixed with the slab and that was providing some stiffness and frame action. So that was providing stiffness. So that attracted more earthquake. But now after I've pinned them, What happened is the building became less stiff, so it attracts less earthquake forces at my overturning moment when down by about 1300. So my overturning on the core now which is 14,800 in comparison to the global overturning moment of 15,731 is about 94%, which is consistent with the results we got from the static earthquake analysis. In terms of percentage, we're getting 91% over there. We're getting 94% over here. So that's pretty good result that our courts are taking all of the lateral loads of the building. Now, the tricky part, let's start checking our drifts of the building. So let's go to story plot responses again. This timeless switched diaphragm drifts. And let's look at the dynamic non ductile load case. And as we can see here, we are getting about 0.0.0 five head. If we reverse that, that is a hide on 186. So straight off the bat, a height of 186 passes the Haydn 66 requirement of the code. But I think it's a little bit high. So what I would like to do here is switched on my p delta analysis just to make sure that my design forces add my drifts are still within the limit. And I designed for the secondary effects of the building because it looks like it's deflecting a forbid. So I'm going to unlock the model. I'm going to go to the find P delta analysis. Let's add our load cases. So we add our bed load superimposed dead load, 30% of the live loads. Now we don't have a dynamic earthquake load cases option to add and our p delta in E tabs for what we can do is we can use the static load case, and we can factor it out based on how much was equivalent to the dynamic case. So we've seen that in the x-direction it was almost the same. This is limited tactile case. We need to factor up by two. And in the y direction, it was about 65%. So we can say it's a 65%, but we'll factor out by two and we'll add that comes up to 1.3. Now we've added equivalent static forces to represent the dynamic earthquake results that we were getting for our p delta checks. Let's run our analysis with a P delta. And again, that might take few minutes. So the analysis is done here. And if we start looking at the drift again, now it has gone up from 0.0.0, 532, 0.0.0, 6544. Which if you inverse it gives us a ratio of around the height on 152, which still safe and passes the limit of Highland 66 required by the design code. What I'm doing here is I'm actually checking the maximum one only which is this one. But what you should really be checking is you should be taking a square root of the summation of the two of them. So what you should really be doing is this was the worst one that we had here. So you should take 0, sorry, 1-0-0, 55, 5-6 square. And you should add the x direction Drift, which is 0.00417 square. Actually the one above at level five is higher, which is now less correct. Level four is the worst, 4417 square and then you square root the sum of the squares that gives you 0.007. And if you inverse that, that's still hide on 140. So you still find what you should always be looking at the square root of the summation of the squares of the drifts in each direction. So in conclusion, that means that our 200 thick corps work for drift without having to thicken them to 300 thick, and without having to add the header between the two cores using dynamic analysis. In comparison, when we did the static earthquake analysis, we needed to thicken them 300. And we needed to add the headers just to achieve height on 130, which is still worse than height on 150, or heighten won 40 that we're getting from the dynamic analysis. So for that purpose, I always prefer to run with a dynamic analysis. Rather than running with static analysis. One, It's better representations of the actual behavior of the building. And to its less conservative when it comes to the design of the course of the building. And that's why you can have the same exact building. And you can end up with two lateral stability designs. One of them might seem heavier than the other one, or depends how you look at it. The other one might seem that it's may not work, but they both compliant to the code. One is designed to the static earthquake and one is designed to be dynamic earthquake. But obviously, I prefer to always take the dynamic analysis for earthquake for that purpose. And I'll leave it up to you to choose which one you want to go ahead with. Now that we have finished our wind analysis and checks earthquake analysis and checks, the last thing that is left to us to do is to design the walls and the columns are either manually or either using ETags. We will explore that in the next module. So until then, practice these few checks and I'll see you in the next module. 33. Columns Design Part 1: Hello. Now that we have checked our analysis and results, it's time to start finalizing our design for construction. So the first thing that we're gonna be looking at is our columns design. And we are going to be using the tabs frame design function, which is used to design beams and columns as well. Firstly, we're gonna make sure that we are working with the correct assumptions before we start our design. And important assumption that we need to take into account into the model before we start our design. Is the fixity or our combs pinned or are they fixed? If you recall this revision for we were using pin columns with dynamic earthquake analysis design. Now that we are looking at designing the columns which is mostly load bearing on the gravity. We want to switch back the columns to be fixed, to take the moments from the slab, the flow plate that we have defined. And then we can use these moments in combination with the axial load, design the columns. So what I'm going to do is I'm going to save as this model. And I'm going to call this revision five. And this is going to be the fixed column with the dynamic earthquake. And since I've done that, let's switch on back our columns from set display options. Switch on Baghdad columns and click OK. Now I can go to select object type. Let's select our columns, and let's go to Assign frame releases and make sure that we select nor releases and click OK. Now if you notice my display is slightly off. And that is because for some reason, e-Types switch to something called Direct X graphics mode, which we touched on earlier. And its main purpose is to reduce the use of graphics to help you run the analysis more smoothly. If you're using a slow computer. And we don't want to do that right now because we're just working with a model. So let's switch back to our standard graphics. Because that just makes them more, that looks much nicer. So this happened with you, that is how to fix it on the spot. Now let's also switch off our walls because we are not going to need those. Alright. Now we can run our analysis and then get ready to run our designs soon. So our analysis finished running. But there's one thing that I want to touch on quickly, which is our p delta analysis. If you recall from the lateral stability analysis checks we had big drifts on the earthquake. And for that purpose, we actually had our p delta analysis switched on. And we should definitely keep that switched on. Now that our analysis is finished, we can start looking at our column design. We can go to design, concrete frame design. And then we have the menu over here. Or we could go. This icon over here with a drop-down menu as well. So let's look at the view revised preference first. Now here's where you select your design code and there's a lot here that E tabs design for. We are designed to the Australian standards. So we're going to stick with AS thirty-six hundred two thousand sixteen. And if you switch on two different design codes, you'll notice that there is different parameters and different values at the bottom that depends to design code that you're designing to. So if you need more information on that, you can go on the Help documentation. And then you can go to the concrete frame design. And then there is a tab under each code. If you double-click on it, it can show you a, a brief document that explains to you what is every parameter that you're inputting to your design code, and how you can actually understand the meaning behind that and see how that influences the calculation that's done by e-Types. Anyway. Let's close that. And let's jump back into our view revised preferences. Now, the multi response case, we want to consider step by step for our design. 2411, Vesta default, that's fine. Your five factors that is fine. And your utilization limit, one that is fine. I usually don't change anything else over here. If I find a reason to do that. Now we can also select our design combinations. Generally, these ones were automatically generated by E tabs and we don't really need them. So let's first go to the lead, these load combinations that we don't need. So if you go on to define load combinations, and let's select these ones that ETag generated automatically and we're not really using. Delete them. If you recall, these are the world design combinations that we defined and those ones will leave in here. And let's click OK. Let's jump back into off frame design combinations. And let's put the relevant design combinations in here. We're not designing to the earthquake Statics, so we're not going to be putting those load combinations in, but we are going to be designing to the earthquake dynamic just for sheer forces. And we should use the non ductile earthquake. And let's click OK. Now we have defined the load combinations that ETF is going to use to design the columns four. And now we are good to start our design check. If you'll see it starts checking them and it can highlight the column that is checking in the background. And it shows you a progress bar at the bottom right-hand side. And then when it's done by default, it will show you how much reinforcement you need for the columns. So it can be a little bit overwhelming to look through all the columns. What I usually like to do is to reduce my view range to the critical story that I'm looking at. In this case, that critical story is going to be the lowest story in the building. So I'm gonna go to view, set building view limit. And I'm gonna change the top story to level one. And I'm going to click Okay. So what it's showing me is everything that's between level one and the ground. And that's basically what I want to see. So I'm going to close this tab and maximize my viewing window in 3D. Now, the font is slightly smaller. So what I'd like to do here now is go to Options, graphics preference, and increase my maximum fond to ten instead of five. And click OK. Looks like my small font is delimiting, So let's increase that also to five. And click OK. Alright, let's increase a little bit more. Ok, that's much better now. And now what I would like to see is also switch on my design display information. So if you go to that one, and instead of looking at the Reinforcing, we can look at the rebar percentage and we can click apply. So eta is going to tell you that basically the column works as long as it's less than the maximum percentage of enforcement, which is 8% for Australian Standard. But still that's a high amount of enforcement and you don't want to have 8% in your column unless there's a dire need for that. So first let us do our initial check. We can go to our column framed design and we can actually click this, verify all members pass. And it says one member has failed. You want to select it? Then I click yes. Obviously I can see it here because it's in front of me. It says ONE S, but I can also right-click and show selected object only if I'm not sure where is that column. So now let me switch back everything again. And let's do our visual inspection on the column periods percentage. Now, generally, if you want to achieve an economical design for your columns, you want to keep your reinforcement to a minimum because it's more expensive. And you want to maximize your concrete grade as much as you can without compromising too much the architectural design. Now keeping in mind that this is an office building in creating the column by 50 mil or so in every dimension is not going to be a big compromise. But if you were designing an apartment, for example, building or a car park, where increasing the width of the column might have an impact on the area of the apartments or on the clearance between the car parking spaces required, then it might need a little bit more thought in terms of how are you going to deal with this? Whether you're going to use a high you depart rebar percentage or a higher concrete grade. But in our case here, it's pretty clear that this higher reinforcement percentage is not really a good design in this case, assuming that some office space and the architect is fine with increasing a 50 mil concrete of the column in either direction. So what we're gonna do, instead of sticking with our 450 by 450 column, we're going to increase that 500 by 500. And then we'll see where we can go from there. Alright, so let's unlock our model and start defining the additional sections. Let's go to the define section properties frame sections. And let's remove C1 from this because we're not sure yet. And let's add a copy. But this one, let's call it a 500 by 500, and we'll leave it as 40 MPA. Now we'll add a few different concrete grades for this 500 column just to actually maximize using our concrete and minimize the reinforcement when we go into a design option again. So let's define our 50 MPA concrete column. We actually don't have a defined in the material, but we'll just quickly add it in like how we've done in a previous lecture. We're going to add in the New Zealand concrete guy, go ahead with the 50 MPA. For 50 MPA. Our young modulus is 34,800. And we'll just gonna make sure that this is defined as 50 MPA. And let's add another one. Actually, let's change the name of this. Let's just call it the 50 MPA, and let's add 65 MPA. Now we don't have it in the New Zealand standard then eat app doesn't support Australian material standards, so we're just going to have to be phi manually. Our young modulus for 65 MPA is 37,400. And we're just going to have to input this manually to be a 65 MPA. And click OK. Now we're going to switch this to a 50 MPA because we're defining a 500 by 550 MVA column. And let's add 65 MPA. And let's click okay. So now what I'm going to do is I'm going to select all of my columns. I'm gonna select my object type columns. I'm going to assign my 500 by 500 with a 40 MPA concrete grade to them. And I'm going to run my analysis again. So my analysis is finished running, and now it's time to run our concrete frame design and have a second look at those desired results. Now let's click on the drop down and go Display design information and look at the rebar percentage again. As we can see here, it's much better. It looks like most of the columns work with less reinforcements. Let's check that all members past. And E tabs gives us a prom that all the concrete frame members of puzzle design checks. So we're happy with that. Now we want to optimize our enforcement percentage is much as we can. So we definitely want to group the columns in different groups with different concrete grades and tried to keep our enforcements to 1.5% on average. And for the heavier columns we can go up to 2%. So all of these columns or 500 by 500 square with a 40 MPA concrete grade. I can select the ones that exceed 1.5% and assign them to a 50 MPA concrete grade. So let's do that. So let's select this one. This one, this one. All of these exceed 1.5%. Points are fine. Alright, so I've selected all the ones that exceed 1.5%. And I'm going to actually revise their override. And I'm going to assign to them a 50 MPA concrete grade and see how that goes. And also I'm going to assign them to a group. So I know that these columns later on when I unlock my model, I actually need to increase their concrete grade. So I'm gonna go and assign them to a group. Let's define a new one, and let's call it C2. And that is going to be 500 by 550 MPA. And we'll, we might need another column, which is a s3. It's gonna be a 65 MPA. Alright, so those ones I selected, I'm not sure if they're going to be 50 or 65, so I'm going to add them to the 51st and click Apply. And now I'm going to rerun the design again. We don't need to rerun the analysis because I have the sections defined as just give them a different section and now they're just checking the design for us. Let's show our bar percentage. That's much better. Most of my columns now, less than 1.2 to 1.5%. I'm left with the heavy columns on the inside. So now anyone that exceeds my 2%, I'm kinda put it in another design group, which is this one. This one. This, this, this, this, this, and this. So all of these ones exceed my 2%. And they basically need to go to a 65 MPA. So let's go to View, revise, overrides and put the concrete grade up to 65 MPA. And let's assign them to the 65 MPA. Actually first, let's delete them from the 50 MPA. And let's go to previous selection. So we can get them again. And this time we're gonna add them two or 65 MPA and began to click Add to Group. Alright, so let's rerun the design one more time. And the design is done. Switch on the rebar percentage. And now most of my columns are within the 2% reinforcement, except for this one column here, which might need to go up to 80 MPA or am I just used the higher enforcement for all this column type. So let's see how many columns are actually using this type. So if I go to select by groups and I select my 65 MPA, you'll see here that I have eight columns. And if I show only those eight columns, it's these eight columns that need to be a 65 MPA. Now, all of them actually work with about 1.6% of reinforcement, except for this one that needs an additional 1% of reinforcement. It might sound like a little, but increasing seven columns from about 1.6% to 2.7 is a lot of increase. Its 70 to 80% increase. A free enforcement for seven columns increased over eight story building. Now that could be worse if it's a taller building. So what I would do in this case is just use a higher concrete grade for that column. It might be confusing for site in some occasions to have just one column only that is 80 MPA. So in this case, I might just leave these five columns as 65 MPA. And these three columns, I'm gonna increase them to AMPA and use the smaller enforcement. So that way of group at least three columns with the same concrete grade instead of only a single column. And I did not increase their enforcement for seven columns because of foreign. That way I've made it simple not to be overlooked foresight. And I've made it economical by actually just meeting the minimum reinforcement of 1% and maximizing my concrete column size and concrete grade in achieving my design load. Now that design philosophy may not be suitable for you in your geographical occasion, if you are in Australia or if you're overseas and you don't have these concrete grades available to you. Definitely consult another colleague in terms of what is more economical for design. But in 90% of the cases using less reinforcement and more concrete is the optimal case if you have no choice but to stick to a smaller concrete column size because you're limited Harbour Space and you have to compromise on the structure because of that, then you have really no choice except for going with the higher reinforcement. Alright, I'll see you in the next lecture when we start creating reports of the column designs that we've just finished. 34. Columns Design Part 2: So now we want to export our design formation in detail to document our design of these column. The way to do that is to go to File, Create, Report, and add a new user report. And you get a following settings. Just because it makes more sense for a column design report. So let's call this the port one. And this is our column design report. And basically elif most of this the same. If you go to the second tab for definitions, you deselect everything and the important information that I like to include and it doesn't take very big space in the report is the material details. That is to show the concrete grade that you've actually defined in your material properties. The section details to show the properties defined into your section. Which can, they can be very helpful to spot any problems in the section definitions. If you have any in your model. And also the load case details and the load combinations. Because if someone is looking at the design report, The only thing that shows there is what is the critical load combination. Even though we try our best in the description of the load combination. To clarify that this is 1.2 g, which is gravity and 1.5 Q, which is live load. It might not be clear enough to some people who look at the report or it might have a factor mistake Connie inputted. So having that definition and that report gives the confidence in what you are actually using to design for. If we go into the next step for assignments, we just deselect everything. And the reason we selected everything and we're not going to take everything off from the assignments is because this is more specific reporting style that we're not after. So we're not after actually giving information in terms of what is this frame number and while section of that frame number doesn't have any offset, doesn't have any releases, doesn't have any property modifiers, or is there any load directly applied to it? And the reason that is because this is usually presented in the report fair screenshots. Because if you want to present this information in the report is not very meaningful to start with because the report is just all clustered over a lot of different pages and it's very difficult to read. And you can't really see which frame is which number. Which makes it that extra bit more difficult for anyone that's looking at the report to actually interpret it, understand it, and it eats a lot of pages in the report, so not going to tick any of that on. And I generally don't recommend it as soon as switch it on and see what it gives you, that's fine. But I think at the end of the day you will come to the same conclusion. If we go to the next tab, that's output. Again, I'm going to deselect everything. And I'm not looking to get any of these specific outputs for the, for each column. Because again, that can be a lot of information that I'm not after. The critical design load combination in terms of bending moment, axial force and shear force is actually going to be presented in the design tab. And so I don't need these detailed information in the report. Because if I just click on that column forces, it's going to increase my report size from 300 pages to about two thousand, three thousand pages. And I'm pretty sure no one is going to look at that much amount of pages. So you better off presenting these column forces in another way using Excel or a spreadsheet. So let's take it off and let's go to the Design tab. Now we want to switch on our concrete frame design. We want to switch on the summary of the results. And we want to switch on our calculations. And we're going to click OK here without selecting any of the groups and named items. That's usually for graphs. We don't need that right now. And let's create the report. If you notice here is generating it at the bottom. And there's my report, it's 147 pages, which is totally manageable. If I came through it. There is my material properties, the concrete grade views, the Poisson ratios, my concrete grade as well. Here's my reinforcement that have defined my tendons, my frame sections, which are the columns that we've used in the models for FAR. We've got our load definitions and how much it includes. In terms of self-weight. We've got our modal cases, we've got our p delta. And also importantly we've got our load combination. So we can see that in the 1.25 g, We've got 1.35 of the dead load and 1.35 of the superimposed dead load. So we can see that we didn't miss on the superimposed dead load in there. And if we keep going through, that's our load combinations. Here is our property that we defined for the frame design. And now that's what I mean by some of the tab group. It helps reports are clustered because it doesn't create the landscape. Paging creates a portrait page and it splits the table into Part one and then part two, and then the information is just so difficult to read sometimes. Think E-Types has a long way to go in terms of improving this functionality for creating reports. Tens of squeezing, squeezing in the tables, or changing the page format to be landscape to suit. Now we can see, start to see actually our columns now. And then we can see the critical load combinations as governing their design. And we can see the reinforcement required for that and we consider design actions for it as well. So most of my columns actually. Critical to 1.2 g and 1.5. Only the highest Florey and the roof are the ones that are having the wind or earthquake because we have quite a little compression load on the column and we have a little bit of framing action going on. So the bending moment from the framing action start to be more critical than the light compression on the column. But as you go down to the level below the roof, you'll start to see that compression starts to govern the design straight away, all the way down to the lowest floor in the building. And then on the next, you can see the shear design. All of them are designed critically to the earthquake. As expected. Gain just eat up splitting the tables. This concrete joint envelope, you generally don't need that except if you're designing to the New Zealand standard. One thing that it actually didn't put in the report yet is the detailed calculation for each column. And to put that into your report, let me close this. Actually, I'm going to leave it open as a tab. Then we're gonna go to the other tab here. And what I'm going to do is I'm going to reset everything, show everything. I'm actually going to unlock my model. And I'm going to assign my sections. So if you notice it only selected 15 frames, didn't select all the columns across the height of the building. So I'm going to switch to all stories and select them again. So now I've selected my 50 MPA columns and I'm going to assign them 500 by 550 MPA concrete grade. I'm gonna do the same with the 60 MPA concrete. So I'm going to show them only still working with multi-story. So when you click on them, it selects all the floors. And I'm going to give them a 65 MPA concrete grade. Let's switch on a bit of a higher floor just to make sure that we've selected everything correctly. If I select my 550 MPA and show everything up, select by frame section. If I select my 550 MPA columns, show selected objects only. Yep, that's correct for the 50 MPA, if I select my 65 and showed them, yup, that's correct. If I select my 40 and show them, that's the wrong one, select this one. Yep. Okay. Now I'm going to assign them to the correct groups just to export their design detailed design calculation. So if I go to assign, I have to select them for sludge, select the 40 MPA, and go to assign to group. And let's create a new group. We'll call this C1. And that's our 40 MPA. So let's add these two. Group one. Let's select our 50 MPA. Selected them, let's add them to the 500 and let's replace everything that's in this group. Let's select our 65 MPA, add them to a 65 MPA group, and replace everything in that group and click Apply. Now, let's rerun our analysis. I just wanted to take a few seconds to explain why we had to go and assign the properties to the columns and assign them to groups. So initially when we did our column design, we actually changed the column section for the design. But that doesn't make E-Types change the section for the analysis. And that could be sometimes a problem because it means that the section you used for the analysis is not the same section that was used in the design. So be careful to always go back, unlock your model, and assign the correct section to the columns, and then rerun the analysis again. If you can see that the, when we change the section, we assign them to group initially in the design stage. And the purpose for that was to make our life much easier when we unlock the model and we want to assign the section now for the analysis that we have this group selection that we can say, okay, this group is the one that we decided is going to be 50 MPA. So we can select it using the group function. Then we can assign the 50 MPA column to these groups. And then we can rerun our analysis and design and create our final design report. Because it's very easy to lose the final design information in the iterative process of design and changes. So it's always important to manage that properly during the design stage. Now, let's go to our dropdown menu, select design groups, and basically add our C1, C2, and C3. And click OK and run our design. The reason we add these design groups into the column design is because it tabs only export the detailed cone design of groups. So if you wanna see the detailed design, which looks something like this, if you right click on any of the columns and go to the details tab, there is a nice frame design report that ETags only output for the groups. So when you put that on and we have already assigned the columns were correct groups. If you remember our report. If we go under our reports tab, which automatically opened by the way, when we created the report. If for some reason he cannot find there that you can go to Options. Show model Explorer. Then it should come up to you. Then you can go under the Reports tab. And this is our report that we generated earlier, column design report. Let's right-click and modified. This time. Let's go to our design tab and let's select the group says gonna export that detail calculations for. We're going to select our C1, C2, and C3. And we're gonna click OK. And let's create the report. Now if you notice my report now is 400 pages previously it was only 157 pages. The reason for that is, you will notice now there is a section here that is called design better. So if you go to that section and if she go, they're starting from around page 148. You will start to see our detail concrete frame design calculations from E tabs, which is very meaningful because it can actually show you a very helpful information that e-Types using a design such as the section type. How long was the column? What is the live load reduction factor that was used for this column on this floor. What is the column dimensions? What is the cover of the column? What's the concrete grade? What's the Young modulus? The FY of the steel, the phi values used in the design and the design actions at the top and the bottom of the column and the controlling design load combination that cause these design actions. And that is for axial and bending moments is for shear reinforcement in the major direction and for shear reinforcement in the minor direction. And then it shows you this information for every column at every floor. So this is C1 at level nine, shows you the same information that story eight. It shows you that design information, story seven and so on and so forth, all the way down until the ground. Now, with this report, I'd usually take a screenshot on the plan. So if I show all objects, if I show undeformed shape and switch on my column labels. So if you go to object assignments under frames, switch on labels and click OK. Now you can start to see reduce their view to only level one. You can start to see that this is my c1, c2, c3, c4, c5, C6, C7, and so on and so forth. So when you look at the report, you understand this is C1 at level six, okay, that's the corner column over here. Then you can look at its design data straight away. And so that is how we present this information. So I can then save this as a PDF file and then I can take a screenshot of this, or I can save it as a Word file and then copy it into my design report and take the screenshot of this capturing labels of each column. So the person who's looking at my design report can understand this is which column and where is it located at? Now one last displayed trick, if you ever needed to actually look at the detailed column forces for each column or each floor. Let's go to display tables. And let's go to analysis results, element output. Let's look at the frame output column forces. And it is very important here, the select the load combinations that you want to be looking at. Let's say we want to look at all of these load combinations. And we want to have all of our Load Analysis, sorry, our load cases. And let's click, okay. Now it tabs, gives me the results of the columns, which I can then export to Excel. And from Excel, I can create my filters. So if I click here at Salt sort and filter, if I click Custom, sorry effect click filter, then it's very easy for me to select the column that I want to look at. Say I wanna look at column C2 and say that I only want to see my 1.2 g and 1.5 Q, which is this load case over here. And I also only want to look at the bottom of the column. So 0 is the bottom. And usually the other number is, is mid height or the top of the column. So I just want to look at the bottom of the column. So here I have the s2 column forces from level to level one. These are my compression loads. Negative is compression. These are my minor and major share my torsion, my minor and major moments. And I can basically just switch between the load combinations as much as I want. And I can switch between different columns or even between different floors and quickly create another tables or just copy pasted in my report if I need to do that, which is much, much more meaningful than exporting this into a report from E-types because E tabs reports just don't come out right. A CMS clustered on different pages like what we've seen. So I hope that's helpful and I'll see you in the next lecture when we look at the walls design. 35. Wall Design Part 1: Now we're going to start looking at designing our core walls, easing the Cornwall stresses as well as the tabs shear wall design function. But before we can do that, we first need to define our pier and spandrel labels for the world. So we can design them using e-Types. Alright, so let's go back to our views headings, switch or columns of an switch, our walls back on and click Apply. Close. And let's increase our building via limits all the way to the top. So let's look at the pier and spandrel definitions by CSI. So appear as explained before, is think of it like a column basically. And it, it is designed for mostly compression load and in-plane forces at the top and at the bottom. Wireless spandrel. Think more of it as a beam that is designed to spend horizontally between two ends. So if you look at this example from CSI over here, we have at the top P1, because it is very wide and long wall here. And then it gets played by an opening. So we start to have a P2 on the left-hand side. We start to have a P3 here until we go down to a very long portion of the wall again, which is a P5. And we have a small P4 here similar to the P3 wireless panel, for example. We have this opening over here and we have this portion of the wall that is spanning horizontally between each end of the opening. So that is a spandrel. Similarly over here also, if you want to design this, overhears a spandrel and you want to check it for right and left. Of course, some pairs are less significant than others. For example, we probably don't want to check this P50 over here because it's actually quite a riot. It's quite long. There has been a good spread of compression. But maybe this p3 and p4 is more critical because maybe the height is going to become an issue. This p2 is quite important. Maybe it starts to become slander and require a lot of reinforcement. But P1's is going to have a very good spread of floats who generally, that is not a very significant one in this case, for example. So let's start applying that into our core wall design and see its significance. Let's add a new window and switch on our grid. Let's start first with the simple one, which is the great line a. So let's go to this 3D and click on elevation. And let's look at core to grid line a. As we can see, this is just one big chunk of falls that is generally going to have only one pier label. So the way that we assign the pier label piece by going to define. Sorry, we first have to define the peer level before we assign it so we can go to define pier labels. And let's create a new one. Previously we had the core one and core two. But now let's, let's be more specific. Let's say that this is core one, peer one. And let's create it. And let's add another one's while we're here. And let's also add some for the second Cold War. And let's click OK. Now we've added our peers. What we can do is we can go to Assign shell, pier label. And if you notice, we can actually apply pier and spandrel labels even after the analysis is already run because parents panels do not affect the analysis and they do not affect the results. They are just an assignment. Basically, to add together all the design forces for that shell that you assign this peer to and then use this information to design it. So it's more of a design function and doesn't affect the analysis at all. Select, Assign, shell, pier label. Let's switch to working with all stories. Let's select all of these core one walls. Or we can just select them through the window and assign colon p1 to it. If you notice on the 2D, it didn't get updated yet. But if we click here and move a little bit, now it gets updated. We can see that this is our core one, P1. And let's do the same with the score to, let's give it a call to peer one assignment. Let's go to the next grid view. Now we are looking at germline B, which is the internal one. Again, there is no opening nor complexity here whatsoever. So we'll just give it the simple pier labels because we're interested in the design results at the top and the bottom of this hole. At each level. That's it goes to the next grid. And again, it's the same thing. If we zoom in over here, we'll see that this is actually a situation where we need to divide our shells to apply the assignments properly for the pier and spandrel, because this is an opening here. And basically we have this as our main peer. And we have this small header on top of the opening as our spandrel that spans loads horizontally between this pier and the wall on the other side. So what we need to do here is we need to unlock our model. Essentially, select this wall, select disjoint. Go to divide options. So we go to divide edit shells, divide shells, and we split them at the selected joint objects on the edge. Now we've split them correctly. So we can see that this is the peer that is correct. This one should not be appear. So this should actually be a nun. And it should receive a spandrel assignment. So let's go and similarly we can go to define spandrel labels. And we can start adding core to spandrel one for example. And don't take the multi-story because the multi-story is going to assume that this panel spans between different floors as well, which is not the case because the spandrel is only below a level one. Above level one. We have our wall that is spending between the two floors pretty much. So let's click OK here. And let's select our header and go to Assign shell spandrel labels. And let's give it the court to spandrel one application. Alright. We can actually switch off our pier labels just to make it clearer. Suite that goes to the next group. Our great one. Great one is a little bit different. We can see that e-Types automatically apply the spandrel label to these headers because we created these using the tabs, multicore wall functioned automatically, used, automatically created this Penrose for us. So we don't need to assign the spandrels here. But what we need to apply is the pier labels. So we're interested in these ones over here because they are taking a fairly big compression load from the top and they span from floor to floor. So let's give this the last one we used was you can check over here. We've used call to P1, P2, and P3, so we can use before now. And let's click apply. It's not showing, I think because we have hidden. And similarly, let's also apply pier five for these ones. And these ones that spanned the full height without any openings. They can take P6, which we don't have. We can quickly add it from here to here six. And let's apply it. Now if you notice we have the old ones here where they had the label of CO2. We don't really need to check these as peers. So we can just give it a non pier label because we don't need to design them. We're more we're more focused on the major piers that take the gravity load down. Similarly, these ones here, we're just gonna give them none. So our critical peers are the vertical legs of this Wall and the end big like of the wall. Now. Look back at the spandrels. We have the spandrels, these ones, S2 and S3, that are spanning between the vertical legs of the war. I just noticed that this one was not applied correctly, so let's fix that as well. All right. Let's move on to the next elevation. It's a full elevation without any openings. So let's give it another pier label, this one, we're gonna create a new one for it. Let's call it C2 here seven. And while we're at it, let's have also peer eight and Pier nine and period ten. And let's click. Okay. So we're gonna give this pr seven. And let's go to the next elevation. Alright, that's it for the courts to. So you actually need to go to the core one now, on grades a, B, and C are going to be exactly the same. We already assigned a pier labels to them when we were working with a core tool because they had the same elevation. On this one. There is an opening here. So first let's give everything or core one, a peer for label. And then let's zoom in to this floor with an opening. So let's, let's think again about our definitions of appear. So appear is basically a portion of the wall that takes compression and in plane bending from floor to floor or from the ground to the top of the opening, like in this case. So what we need to do here is we need to split the shells at this opening locations. So we select this and this joint. And again we go to edit, edit shells, divide them, and divide by selected object, joint object on the edge. And we also need to split this one. We'll do the same with the other side. And now we have split them. So what we have now is we have this as one pier label, and we have this as another pier label. Now because they are on the same elevation, I don't generally give them an x number. Instead, I just create a new one and call it p4. And P4 be. It just makes it easier because I keep the same number on the elevation on I only change the lighter. So this is going to be my court to peer for a and this is going to be my core two, peer 4B. Alright, and at the top here again, I don't really need this because if this over here works in compression and in plane bending, this one is definitely going to work as a peer. So I'm just gonna give it a nun, but I need to give it a spandrel label. So the way I can see that is I can go to my shell assignment, which was from Assign shell spandrel label. This one over here. So if I just click on anywhere and click Apply, it says there's nothing selected. I know that I just wanted to see that because when you do that, it actually switches on your spandrel ID. So you can see if there's any spandrel assigned here. Now you notice there is no spandrel here because this opening was created manually when we started cutting our core walls manually and it was not defined automatically in the cold wall stacks of E tabs. So we need to give it a spandrel label on its own. So let's go to modify it to create a new one. And let's call this our core one, spandrel one. And let's add a new click OK. Select our header that's above the opening and give it the court to spandrel actually call one span row one, and click Apply. Alright, moving on to the next elevation, which is the last one. Again here we can see that because we have those nice openings created by e-Types cobol stacks, we don't need to define our spindles. So let's close our spandrel labels and we're happy with how it is. And let's work with our pier labels. Again, don't select anything and just click apply. It's going to tell you nothing selected and switches on the pier labels for you to say similarly with other elevation. Now we need to start giving these ones. It's pier labels. So we've used up to peer four. Let's look at the plan to double check. We've used 12. It looks like we've given the wrong pier labels to this one over here. So let's jump to our core. One, elevation one. We've given it a C2 P4 When it should in fact be having C1 P4. So let's quickly go and fix that, that select everything. Let's give it C1, p4. And let's select the ones that we don't need, which are these ones, and give them. Alright, so now that is fixed over here. We forgot this one because we didn't look at the grid lines C. Let's quickly jump in there. And let's give it C1 P5. Alright, so we've got c1 P1, 2345. Now we need to create C1 P6. Again because we are going to have a lot of openings on this elevation that will just looking at it. So we're going to add six a, 6B and six C. And when we jump back to that elevation which is core one elevation to, we can just quickly select everything and give it a non peer selection. Then we can go and say these ones over here. We can give them core one, P6, a. These ones over here. We can give them colon P6 be these ones. We can give them cool one P6 C, And we actually need coal one P60. So let's modify and add our core one, P6. Alright, so we have our periods defined now. And if we look here, we can actually see it on the plan just to make sure that there is nothing that is having duplicate peers. Sometimes she'd get weird results. It means that you have actually more than one wall having the same peer and that's why the results are a little bit weird. You can check it by visual inspection first to make sure that you don't have that in your assignments. If you somehow missed it, don't worry because when it comes out the design results, it's just not going to be right straight away when you see it. So that is going to prompt you to look back and just double-check. Where is this pier label? Let's do our check in 3D. But generally looks okay. Also, another way to quickly check it is when you're viewing it up close, you can let, let's just close all of this for now. You can actually go to select by p label. So if you go to label by pier label and you can actually start selecting, all right, show me my c1 P1. You can see it's only these ones over here. Or you can right-click and show selected objects only so you know, right? That's, that's correct. Then you can go on checking one-by-one just to make sure that they have the correct pier labels. If you really want to do your due diligence before we even start running your design. Alright, let's start running our shear wall design now using these peers and spandrels in the next lecture. See you then. 36. Wall Design Part 2: Now we got our peers and spandrels defined in the model. So let's start looking at the shear wall design. So we can go to design concrete shear wall. And then we can look at the options for the she-wolf design or similarly with a column design, it's also located over here where the drop-down menu. So let's click on the drop down menu and let's choose our preferences. Again, you've gas like the concrete code that you are designing two, we're gonna stick with AS thirty six hundred and two thousand eighteen, you get a health response. Basically, this is for checking every case of the analysis and the envelopes that you have, instead of just checking the maximum and the minimum, might take a little bit more time, but it's the most accurate choice and it's the default one. You rebar, which is going to be used. We've already defined our 500 grade n bars. So you've got to check these. Instead of the default ones. We will leave our five factors as per the default. Pmax is basically the maximum compression that you can have on the wall. And by default, etag sets it to 80%. Number of curves and number of points will leave that as it is. The edge P T maximum is the maximum tension reinforcement that you can have at the edge of a wall. By default, I don't like to have a lot of reinforcement in the walls because it can get very, very congested. So for tension out usually put that to maybe about 2%. Worst-case, you can put 3%. But what this does is when he put it to 2% and e-types finds that some of the walls need more than 2%. It's going to tell you that this whole failed. But it didn't actually fail, that just didn't work with the perimeters you input. So if, if this happens in this case, then you can increase it from 2%, 3 percent and basically designed for that reinforcement, but starting with a 2% for the water enforcement is a good start. Similarly with a compression, again, I'd just like to keep it to 2% reinforcement. And that's because most of the cases you're just applying uniformly enforcement throughout section IP, maximum and minimum. This is the maximum reinforcement when you are using a uniformly enforcement, again, not 4%. I would like to just leave it at 2%. And the minimum reinforcement is 0.0025, which is the minimum for crack control utilization factor limit. Again, this is your demand on capacity ratio, density ratio, 95% is generally close enough. But if you really want to push your design considering the safety factors, you can push this to one, and that is also fine. So let's click OK. Now let's look at defining the load combinations that we want to have. It already took all of our UD wall combinations, but we need to be careful here. We're not designing for the service ones. Technically, we can leave them, but just to save some computational time, we can take it out. We don't need those service. Cases. Also we are not designing to a static earthquake, So we take them out. And also we are not designing to non-doctors earthquake we only used on under fell to check for cracking and to check for deflections. But when we designed with designed to our limited ductile earthquakes. So we've got our earthquake about wind cases and our gravity cases, and that should be good enough to design the rules. Now if you recall, we are also working with version five of the model, which is having our columns fixed. And that means that we have less moments on our core walls. So what we want to do over here is actually save as this model instead of using the older one. Because if you remember when we finished designing our columns, we actually updated their sizes in the model because we always want to be working with the updated information in the model. So let's call this a revision six of the model. And this one is going to have our columns pinned. Which is the suitable assumption when we are designing the forces in your coal walls. And obviously this is going to unlock our model. Switch off the walls, switch on the columns a. And as we've done before, to select all of them, go to Assign frame releases. Unreleased the top and the bottom on the major axis and only one end on the minor axis. Otherwise, it creates instability in this stiffness model. And also with the columns of the lowest story, we always need to make sure they are not pinned at the bottom and you're only released the top. So let's select them and go to Assign frame releases and only make sure that we have the top released and not the bottom. Alright, so we've released our columns, let's jump back into our walls design now. One thing that we need to touch on is the type of shear wall design and analysis that e-Types is carrying out. So let's jump into help documentation. Shear wall design, and opened the tab that's corresponding to your code. Regardless of which one it is, it's going to have the detail explanation of the three shear wall design type. So let's open the AS3 602,018, which we're designing two. If we jumped chapter two for the peer design and jump to the wool peer flexural design. We'll see that the first type over here is a designing of a simplified pure section. And a simplified pure section is basically a peer that's having a column at each end, or they call it a member. And one side is designed tension or compression due to axial forces plus tension or compression due to moment. And basically you add up the forces and you get a net axial compression force in the ends. And that's what eat apps designed for in terms of reinforcement using the standard. Design for RC structures in the code. The other type is a uniform reinforcing section, which is basically assuming that the whole peer section is one big column. And it assumes there is a uniform reinforcement distributed throughout the section. And it uses that to work out the PM and interaction curves and plot your demand to capacity ratios based on that. And determine how much is your reinforcement required to achieve those PM and interactions. Which is fairly straight forward because it's the same design philosophy as it is with columns. And the third type, which is general reinforcing peer section, is a little bit more detailed. Depends on case to case situation. Depends on a unique situations where you need to use a mix of uniform reinforcing and boundary ends of the wall. Like for example, if you have a wall with columns at the end forming a huge boundary elements, you would start to look at using general reinforcing sections. Generally speaking, I prefer to use the uniform reinforcing sections because most of the time woulds reinforcement is uniform and it is less conservative than using a simplified compression and tension, which was the first type. So I've always preferred to be less conservative if I have the confidence that the analysis that's being carried out is actually acceptable by the code. And this results make sense. So let's go ahead and use Danny form reinforcing in this project's Let's close all of this. Let's select all of our walls. And let's go to the shear world drop-down menu and go to assign pure section. Instead of using the simplified compression tension, let's give you the uniform reinforcing. Let's give it 40 MPA concrete grade for now. And let's give it enters. At 250 is with 25 millimeter cover. The N bars will be in twelves as well since it's a uniform reinforcing. And in this case, we're actually, and in this case, we actually want to design our enforcement. So again, check reinforcement to be designed. If we have already done initial design checks and we are comfortable at this reinforcement is going to work. We can check reinforcement to be checked and click OK. And in this case, ETags is gonna give you demand to capacity ratios, or d and c ratios. Instead of giving you how much reinforcement is required, it's going to tell you what is your demand to capacity ratios. But in this case we haven't done that. So it's just going to ask, it helps to give us the reinforcements first. And with this reinforcement that ETag say's required, we're going to design our enforcement. And if we want to, later on, we can come back, select the walls, assigned the reinforcement that we found out that we need, and assign them to be checked and then run our checking and basically print a report with our demand to capacity ratios for all of the walls. For now, let's leave it as reinforcement to redesign. And let's click OK. And first run our analysis and then run our Shear will design by clicking on the shear wall over here. Okay, so are designed finished running, and now we can jump into elevations and check everything in detail. So let's jump into the first elevation. Will start with for one grid and click OK. Now it's showing us the longitudinal reinforcement required for this can be a little bit confusing because that is the total for the two phases along the full length. Instead, what I like to do is go to this plate. These are information same with the column design and make sure that we are looking at their enforcing ratios instead. So when we do that, we can see here that we need about 0.7% and then it jumps 2.0. 3-7. Here is also about 0.03%.6 and then jumps to the minimum after the ground floor. If you want to see more details, we can right-click on the wall design. And over here, again we can see the PLA table. You can see the length of the wall. We can see the thickness of the wall. And what is the live load reduction factor? We can see the concrete grade them young modulus that was used, the FY of the steel reinforcement, the five factors and the reinforcement ratio that we defined into the design tool. And then down here, we can see the required reinforcement. And how much of that in terms of percentage. And what is the governing combination? Over here we can see it is the earthquake combination with compression load of this minor axis and major axis moment of this. Now if you notice this is negative. So it means that the wall was actually on the tension. Negative here is actually tangent. So this 100000233 kilonewton with the negative sign is actually attention one. And you can see the shear design checks and how much reinforcement is required for share. So to just verify this quickly, we can actually close this and we can open our peer forces. So if we go to this play frame of peer forces, if we select our load combination 35. And if we look at the axial force for peers and click apply. And we have a maximum minimum selected. If you right-click on the wall, we can see that we have a maximum tension of one hundred, two hundred, which was negative and appeared design because it's tension. And we have a minimum of negative 2800, which is in compression. So this confirms that just ETags reports the forces and the peer design actions allele differently in terms of sign convention. So when you're looking at the force and E tabs, negative is compression, positive is tension. But when you're looking at the period design because it considers the local forces, it has the opposite sign convention. So for the peer design, positive value is a compression value and a negative value is attention values. Just be mindful of that. Now we can switch back our design reinforcement information and we can switch between elevations using these arrows. So we can go to B. Again, we have only about 0.6% here. Great line, see almost nothing. Grid line, the 0.5% over here, 0.7%. And this big opening over here. Now that looks to me like a problem because it's only giving me one, but I should have two pier labels over here. So let's see what's the problem here. That switch on our pier labels from other assignments and click apply. Yeah, so we'll see what happened here is we have a core one, P4 on both sides, so it added the results for both of them. So when you're looking here, you'll see that it's giving the information at the middle, which is not what you'd expect. And if you right click on this, actually, you can see that the length of the wall is about seven meters, which is y added both of them. So we need to do here is fixed this. So let's like these balls and give them a pier label of C2 P for coal one. Yeah, right, so we need to add a new one for that. Let's call it a before a and B for B. Alright, so that's my before a. And these ones are the b. Now, if I run my design again for the shear wall design finished running and let's switch on or ratios. And we can see that it's given individually ratios on either side, which is 0.5% here and 0.45% here. So that is fixed. Now, as with the next one, again, we can see that it's only 0.8% here. This is 0.6%, this is 0.7%. And this didn't have anything. So it looks like we had a problem here as well. Let's see. Yeah, we actually forgot. Apply our C1 P6 d over here. So let's select these ones and go to assign pier label. And these ones were C1, P6, D. Let's click apply. And that's on the design again. Now let's switch on our period forcing ratios. And we can see that we have design information for this leg now as well, which is about 0.8%. Alright, moving on to the next elevation, 0.7%.66.555.85.32.35. And that's it. We finished with our coal elevations. Now we have this design information. What we can do then is we can design these reinforcements based on the ratios that ETags is given us. Another way to do it is we can predefine the reinforcements into the wall and let E tabs run aids, demand to capacity checks. Now the next thing that we need to do is check for our boundary elements in the walls. And we will jump into that into the next lecture. See you then. 37. Walls Design Part 3: Alright, so now we have from our design using E tabs and we know how much reinforcement is required based on those strength requirements. And as we can see, it's, the design is mostly governed by earthquake design. And when we're designing to earthquake is not just a matter of providing the required reinforcement for the earthquake in the ultimate load condition. But we actually also need to comply with the earthquake detailing requirements in the code. That is in line with the quality class that we've adopted for our building. In this case, we've adopted a limited ductile shear wall system. And there is a certain minimum expectations and requirements from the code that needs to be provided in the building to actually achieve this limited ductility. So if we jump into our AS 3600 section 14.6 for limited ductile structural walls. One of them is the requirement for boundary element. So if we go to section 14.6.2, we will see that in any story, boundary elements shall be provided at discontinuous edges of structural walls and around openings through them. If you vesicle enforcement is not restrained, which is typically the case for walls. And the extreme compressive stress is actually more than 0.01. five fc dash. So 0.25. fc dash for a 40 MPA is about six MPA. And for a 50 MPA concrete grade, that is about 7.5 MPA. So what we need to do here is we need to look through our walls and see if the compressive stress exceeds these values at unsupported edges, which is usually at the opening location, or if you just have a shear wall. But in our case we have a core wall system. So if I switch on more walls here, you can see that all of the walls at the ends, they are supported by another wall. So all of them are continuously forming a box and they are restrained at the ends, except at the locations where we have opening for the doors. For example, over here where we don't have a return wall to support them, so we just have a wall without any return. So in this case, these regions need to be checked that they don't exceed 0.15 of the concrete grade. So let's jump on and check that. So let's go to our elevations grid a. Grid a doesn't have any of this situation. B, nothing, see nothing. The, we have an opening here. So what we need to do is that we need to go to our stresses, display shells, stress of forces. And let's reach on our S22 stresses, which is the vertical stresses. And let's look at the minimum stresses. Minimum is most compressive stress because compression is negative in Etypes dresses. And let's look for the combo where we have our dynamic earthquake, which is world 35. And we also want to be looking at the minimum result of this combination. And we want eat apps to plot the contours with the minimum value of negative six MPA, which is the limit for a 40 MPA concrete grade. We can actually set the transparency to 0.3 just to help to see you easier. Now, we can see here nearby the opening, our stress actually exceeds its about 6.5 MPA. We're not concerned about this side because we have a wall on the back that is restraining it. We are more concerned about just next to the opening occasions. So what we can do here is we can actually increase our concrete grade to 50 MPA. And in this case, our limits for boundary element is going to be 7.5 MPA instead. So let's plot it with the 75 MPA. And you can see here that it disappears here, but we still needed over here at the top. So increasing our concrete to 50 MPA still did not get it to work. And in this case, what we need to do is provide some links in the wall to restrain the vertical bars due to the high compressive stress. So if we jump back to the AS3 600, it outlines that for a building that is less than four story high, you just need to provide for n 12 bars with our ten legs at 200 centers or depending on the thickness of the wall. But in our case, our building is more than four story. So we have to comply to close 14.6.2, which is that we need to restrain the fitment at a distance that is 200 millimeter or thickness of the wall. And it needs to be for the full extent where there is a boundary element and that extent is basically how far the stresses go. So if we use this 50 MPA, that mesh size is about one meter. So you know that this distance is roughly about 500 mill. Maybe, just to be safe, you can take it to 600 or 700 mil or even you could say for the first meter here, we need to provide these links in the wall. And they are spaced as 200 because our wall thickness is 200. Let's go to other elevations. Around here. We actually don't exceed, so we are good here around here that's adjacent to the opening. We don't exceed over here, we've got a return wall, so we're not concerned about this. Over here. We don't exceed, we don't exceed. And over here we don't exceed. And over here we have returned wall. So that should be a right. Over here. There is no openings or discontinuity. And that is the one that we were looking at earlier. So that is actually there's one more here. We also don't exceed next to the opening. And over here it's restrained at the back. So that should be a k. Over here. We don't exceed. So what is governing a design is really only this wall over here on grid line d, where we need to provide restraining links for the first floor around here. And just to be clear, we have used the 50 MPA concrete grade, so we just need to make at least the first two or three floors with 50 MPA panels. So that is the first requirement. And for the second requirement, we need to make sure that our concrete grade doesn't exceed 50 MPA. Because if it does, that means that we need to provide restraining links throughout the whole wall for the full height of the building, which is a lot of extra cost, given that the cost of steel is always more than just the cost of concrete. So if you find that you need more than 50 MPA concrete grade, maybe it's worth thinking about increasing the wall thickness or outweighing the benefit of increasing the wall thickness versus adding in the restraining links. Another requirement is the minimum reinforcement in the critical tension reinforcement zone. If you workout this equation on the section 14.6.7, you will find that it often comes to about 1% reinforcement for the vertical bars. And this over here comes about 0.25% reinforcement for the horizontal bars, which is the same as the minimum required for crack control. As to where this applies, you can see here if you just have a shear wall, it applies at the ends. And if you have a she-wolf boundary elements, it applies in these boundary elements regions. But if you have a continuous core walls, pretty much applies to any face that could be in under tension, which is pretty much all the sides of the cold wall. So that means that we need to provide this 1% reinforcement throughout all phases of the core wall. We've got a 200 thick wall. And for that 1% comes to about 2 thousand millimeter square per meter. And providing N6 at 200 should be sufficient to meet this. While for the horizontal 0.25%, just providing n 12350 centers each phase. Now, we should also note that these are enforcements only apply for the lowest two stories or two times the length of your core wall, the the greatest slump of your core wall. Any floors above this, above the minimum T2 or usually three stories, you can actually start to reduce this vertically enforcement by 10% per floor. And you'll find that it comes to a minimum of 0.25%, which is required for crack control usually at about ten to 11 stories high. So since our building is only eight to nine stories, it probably is not going to drop more than 0.7% by the highest floor. So you can make your judgment call here on whether you want to reduce it for the highest two or three floors, or you want to just keep it uniform and consistent throughout. Now that we know how much reinforcement is required as a minimum, and we compare that with how much reinforcement e-Types told us is required, which we found to be about 0.5 to 0.8% compared to the minimum of 1%. I'm just going to say that we're just gonna design all the walls with the minimum reinforcement of fond percent. And that should work for all of them. So let's select all of them and go to the shear wall drop-down button. And let's go to assign pier sections, uniform reinforcing. And that's assign our 40 MPA with 10-16 at 200 centers with a 25-minute cover, and the end bars are going to be 10-16 as well to choose that this reinforcement is going to be checked. And then what I'm going to do is I'm going to go here. And these are my lowest two floors. So if I select from left, top to bottom right, it only selects what's within the window. So these are the lowest two floors of falls can go back and I can assign univ, uniform section for them with the 50 MPA instead. And it also is reinforcement to be checked. And I can click OK. Now, after I run my design, I'm expecting that all of the world are going to work, but it's always worth just two i over the results. One last time. So if I go to the shear wall design functions and I go to display design information. And I'll actually this time, I want to see my demand to capacity ratios. And here I can see there are about 770% percent utilization. Over here, it's about 70%. So generally their enforcement I've provided is more than enough. If I want to see it in detail, I can go to actually display, show tables. And I can select my shoe well-designed output. I can select my peer design summary. And then I can click okay. And it's going to open a table for me. And for every peer at every floor. It reports to you how much is the reinforcement you have defined, which is the n6 Tina 200. What is the design type? And we adopted a uniform design and it gives you your demand capacity ratio or utilization ratio. And it gives you how much shear reinforcement is required. So if we go through this in detail, we can see that our demand to capacity ratios are generally fine if we export this to excel. And what we can do here is we can go to the master row, column and we can drop down in our sort and filter and we can click on filter. We can see here, we can actually sort them based on the demand to capacity ratios. So we can sort them by the largest to smallest. You can see that the worst one is working at 81% utilization ratio. We can also have a look at our Sherry bars. 500 works out to be our minimum, which is 0.25%. You Friday selected and we just want to see. And the ones that actually exceeded the minimum requirement, we only have two walls that required more than the minimum, which is our c1 p2 at level one and c2 p3 a level one. So for these walls, we can design them for the heavier enforcement of about 630 millimeters square per meter. If we jump back into our model. And let's say that we want to create the report with the results of this wall design, we can go to file create report and let's add a new user report. Let's call this report to. And let's include same as the column design report. We want to have some material details and we want to have shells section details because wall sections are defined the shells and not frames. We also want to have our load combinations, our load case details as well. And since we're designing for earthquake and wind, we might want to include our ought to wind calculations and our auto wind loads, as well as our response spectrum functions in that we've used in our design and load combinations, then we can go to the assignment. You don't need any actually, under definitions, we might also want to include our mass because the mass definition is used in the response spectrum functions. And we can show our materials summary in terms of the concrete grades and the yield bars of the steel as well. In our assignments, we don't want to show any thes and outputs. We also are not interested when we're exporting the design. So in the Design tab, we want to include the calculation of all of our peers that we've used and of all of our spandrels that we've also defined. You don't need that one. And we've selected everything that we need in terms of plots, we don't need any. So let's create this report. So our report is here, same as the column design will generally have all the information that we've selected previously. And the important one is probably the shear wall design summary over here where we can see the input reinforcements with the demand to capacity ratios, which is exactly the same as the XML table that we had, had looked through. And in the end after this design summary. And actually it reports for each wall which one is the governing load combination for PMN and four shears well-designed. And then in the end it reports in details for each peer at each story. The details such as the concrete grade and all of these other information as well. So let's jump into the last item that we're looking through, which is the spandrel design. If we jumped to call one grid to elevation, which is where most of our generals are located. Each one is designed that each flow differently because when we define the spandrel by default, it is set not to be a multi-story. But if it was set to be a multi-story, what it happens is gonna do is it's going to add all the results for all the floors and just report only one value, which is not correct. Well, in this case because it's a different floors, they can have the same spandrel label and they'll have different results based on the analysis. But the ones that are on the same floor need to have a different spandrel label is what we can do here is we can go to the dropdown of the shear wall design menu. We can select Display design information. We can look at our spandrel longitudinal reinforcement and click apply. If we zoom in, we can see how much top reinforcement and bottom reinforcement is required. And what we can do here is you can actually select these ones only and we can go to display tables. And if you notice here, it shows you an option to only export information related to the selection only, which is kind of helpful. So if I switch this off and I click on the spindle design summary now. And if I export this to Excel, and again, if I apply the filter at the top row here, I can see that for example, if I filter it and I just want to see S4 only, I can see how much is the top reinforcement required, how much is the bottom reinforcement required, and how much is my shear reinforcement required? And I can just envelope my design for that. But because I have the three headers on the same elevation, it just makes more sense to make the design as standard as possible. So I just have one design for those three. So what I can do is I can switch on all the three spindles, select all of them. And I can apply color controlling. So I can go to Conditional Formatting Color Scales and select the second one. It actually puts the heaviest one in red and the lightest 20 in green. And you can see that the worst case is about 510 millimeter square. If I do the same with my bottom enforcing, its also about 470, which means it's about to end 20 bars top and bottom should be enough to achieve that. For my vertical reinforcement. I can also apply the same thing. And I can see that I need about 880 millimeters square per meter. At level three, it drops down quite a lot at the ground floor. But the floor, it's still about 750. So it's a big difference between eight hundred and fifty and three hundred, but it's only for one floor on the roof and one floor at the bottom. And in this case, actually changing the type of their enforcement for these two floors only can result in more problems. And the benefit of actually saving on the material might be offset by potential errors or confusion in documentation when it's not, when there's all different types. So in this case, I will just keep it the same throughout. And our design for my 880 millimeter square per meter shear reinforcement. And again, this 880 is basically, let's say if we are using 12, size 12 links. So size 12 has two legs. We're assuming each of them is about 100 to two legs, is 226226 divided by the league spacing is gonna give you how much reinforcement. So in this case, we need about 112300 millimeter spacing should be enough to achieve this shear reinforcement. 38. Precast Walls Checks: Hello again. In this lecture we're going to talk about precast concrete walls. And they are quite specialized in the sense that they have to be broken down into smaller pieces do to fabrication and transportation limitations. And then they get erected onsite, then they get put back together. And because of that, the design of the connections of the precast panels is a critical component ends actually the main difference between a precast wall and a normal in-situ wall. There are two main connections in precast volts. The first being the devil's. Think of those as the reinforcement that ties the panel at the top to the panel at the bottom. And it's there to restrain the panels from moving relative to one another. But to also transfer any tension forces that you might have between each panel, as well as any shear force that might be heavier than the panel weight itself. The second connection is a constant plate. And a custom plate is, as it's called, a plate that is caused in one of the precast panels on one end. And it's cost on the precast panel on the other end. And then there is a steel plate that gets welded to both plates on each panel at the connection point on site. And the reason that you would want to use a well-done plate is transferred the shear forces between the two panels. So you end up utilizing the design of the wall as a bigger panel compared to a smaller one. Let me explain that. So for a normal big role, say like this one over here. They're predominantly designed for overturning moment on the horizontal shear force due to earthquake or wind. And what happens is that you can have compression force on one end and a tension force on the other end. Plus your compression load from the building. So you'll end up with the stress distribution that looks something like this, with this being tension on one end and this being compression on the other end of the wall. But with precast panels. Problem is if you split the panels, you're going to end up with a much bigger tension forces and a much bigger compression forces. And the reason that is because you have a smaller depth in bending. And because now the wall is shorter and smaller because broken down for transportation, you have a smaller arm. You stresses, if you remember, flexural stresses are always MY over I. And now that we have reduced our y because the depth of the wall resisting the bending is about half. But this actually affects the eye as well. So the ratio is becoming much, much more pronounced because if we expand this equation, you will end up with something like M on bd square upon 6 for elastic flexural stresses for example. So this d is actually squared. So when it gets split into halves, you have the moment on each wall. But actually you double the stresses within each wall because you've reduced that moment arm. But if you put in your weld plates that we've just seen in the picture. And you connect the two worlds together. Or even sometimes you leave a gap between the two panels, say about 500 meter on each end. And it cost concrete on-site together. Either way. By doing that, you connect the wall. So there are one big elements together. And you can use this sort of behavior with much less tension forces and compression forces to design for a new world. Now let's look first at designing those requirements. So as we've discussed, there's two things that you really need to check for UDL. The first is attention. So if you have a core wall like the one that we were looking at, and you find out from your analysis model that one of the walls goes into tension. For example, say this wall goes into tension. And then he designed their enforcement and the wall to resist this tension, you have to provide exactly the same reinforcement through your devils to transfer this tension from the panel at each floor to the panel below it. So whatever tension reinforcement that he provided in the wall, you also have to provide it in your devils as a minimum. For the second requirement. You will also need to provide enough devils to resist the shear on the walls. To know how much capacity you need. First Eagle Award cut, how much is the compression load on the panel above? And you can easily adopt a factor that is based on the local design recommendation in your country. Usually it should be about 0.2. Or 20 percent. So 0.2 of your gravity load that's coming down into the joint should give you your friction capacity of the panels just to resist the lateral shear force on that joint. If that is not enough, then you start to need to add some bells to actually transfer the shear force as well. And this requirement that you will need for the shear, you have to add this area required for shear plus a required for tension. And you will end up with the total number of downloads that you'll need to provide for your panel. Now let's look at the second connection that is critical for the design, which is your shear plates. If you want to see from e-Types how much shear plates you're required to provide along this connection. Let's assume that in our project, we have this C1 P4 appear as one big panel. And this is one big panel. And this is another big panel. And let's try to look at the connection at this joint over here between c1 P1 and C1 P4. So to do that, there's two way to find out. The first way and the easier way is to go into the elevation. So for example, this is core one, elevation 1. So let's jump into there. And let's switch on our stresses for the world. So we can go to this place shear stresses. And we choose a look combination that we want to see how much is the shear force that's required there to be taken by our welled plates. So let's go and choose the earthquake dynamic with limited ductility. And let's look at any of the shear stresses. It's not going to make a difference when we cut or section. So now what we want do is we want to cut a section along the edge of the wall on the left-hand side and eat apple is going to tell us how much is the force that's going through this cut section. So let's go, Let's go to draw section cut. And let's try to zoom in a little bit closer first. Let's jump back to growing the section cut. You click on the first to the top near the connection that we're looking at. And then at the second at the bottom. And as you can see, it'll show you where you've cut that section. And what you need to look for over here is actually the z direction. So this value over here, which is 4,140 kilonewton, that is the amount of shear that is being transferred from this wall to the return wall at this corner over here. The other way to do it is to select the whole wall and give it a spandrel label. But we'll have to define the spandrel to actually be a multistory. So let's call the spandrel precast wall one, for example. And let's add it. And this time we're going to take on the multi-story. Once we have our spandrel label tick down and let's click. Okay, now we have our wall selected. So let's go to Assign shell, spandrel label, and let's give it the label that we just defined. Now if I close this and if we switch on our forces for the same load, which is the earthquake dynamic limited tactile. If we switch on the spindle forces and we switch on the shear 22, which is the major share for spandrels, will see that the forces here is 4,141 on the left-hand side, and it's exactly the same on the right-hand side, which is exactly the same force as the one that we got from our section cut. So either way, that is how you get the shear force required that you need to transfer at this joint location. Similarly, if you had the joint at the middle of the panel instead of at the corners, then you will need to split your wall at the middle and give each side a spandrel label. And then you can find that way. How much is the shear force through that joint? If you want to use the spandrel label method, or you can just go to draw a section, cut and cut it through the middle of the war. Now that we know how much force we need to transfer through the joint, assuming the panel was broken over here. The next thing we need to do is we need to design the type of connection there. In some cases, when you look at this force, it can be too huge to be transferred through welled plates. The other option that you might want to look at is using a wet joint like this one over here, which can get you the full concrete shear capacity for as wide as this wet joint is constructed on site. Now, let's say that in some occasions you have some precast walls that you don't want to be using as your principal lateral loads, stability walls. And they are broken down into smaller walls. Or you just want to use them as lateral load stability. What? You don't want to connect them together and you want to design them for the higher stresses. If you want to model this case in E tabs, Let's save as this model and say that we're going to jump into our level one where we have this wall in our building. Let's switch back our floors or columns and click Okay, now let's go to grow this wall. And let's say that extends. Let's make a bet to a 100 MPA. That is going to be correct. And let's say, yes, we're gonna give it an auto spandrel ID, and let's draw it from C1 to see 11 for example. And because we've done that, we're going to select our C1, C6, and C 11 animal. Simply just go into the lake them. Now if we look at our 3D, we've got our wall in over here. And it's one big piece. Now let's say we want to split it into two pieces. And we don't want any shear transferred between these two pieces. Like what we've done in the past with editing our walls, we're going to select our joint. We're going to replicate it through using Control R. We can use pick two points from the start to the end. And that's split this distance onto, let's click Apply. Then we have our wall with the joint that we just created. And then let's go to Edit. Edit shells, divide shells, divide with the selected joint on the edge of the wall. And we'll see that now we've split our wall into two. But that is not going to stop the problem because e-tags will still transfer the force between the two panels. They have these two joints at the top and the bottom as common. So the way that we can get around this is if we select the wall and if we go to Assign shell, that's released. And if we go specify by the edge, by edge in E tabs, edge one is usually the bottom. Edge two is either right or left, depends on how you draw it. In our case, we drew it from the left to the right. So our edge one is the bottom edge, 2 is derived, h3 is the top, H4 is the left side. So for this wall, we want to edit the properties along edge two so we can switch to H2. And we want to release any in-plane shear force along this edge. So instead of putting in a 0 because that might create some problems in E tabs. I put it to a very small value such as 10. And I click apply. And you'll see here it starts to say AI at the Edge that was edited. So for example, if you did a mistake here, editing edge 3, one mistake and you clicked Apply, you will see that it put it at the top here, so you'll know you made a mistake and you can undo your habit. Now we can do the same for this wall, but for this wall, it's going to be edge for. And we can also give it a very small value over here, which is ten. And we can click Apply. Now we have released any shear force transfer between these two walls along this line. If we click run, our analysis finished running. So now we can actually go and define some spandrel labels here. So let's create PC W2 and take multi-story. And let's create PC W3 and create multi-story. And let's give this one PC W3 and this one PC W2. We can straight away go and switch our forces and look at the sheer two to four are spandrels and click Apply. And we can see here that basically our shear force at the end is exactly 0, which indicates that there is no shear transfer between those two panels. And you'll also find that there is no shear force going through the joint over here. If you do the section cut like we've shown earlier. I hope that you find that useful and you develop enough confidence to go on and design the precast connections. See you in the next lecture. 39. Advanced Grid Systems: Hello again. Today It's a short video regarding using grades and working with grids and complex building layouts that is not perfectly aligned to the greys all the time. In reality. This e-Types model is from a real life project that I've worked on. And if we go to one of the plans, we can see that the core was actually not mine to the green with the building. And the building is not directly oriented to the north direction and actually offset at an angle of about 13 degrees from the north direction. So that complicated a little bit and it becomes handy when you have the grids for the core wall and you have the grids for the building separate. So for example, if you right-click and we go to our set grid system visibility, we can see that we have G1, which is the great for the core wall system. And we have G2, which is great for the building system itself. And we have the G2 switched on right now, which we can see it's the building grids. If we click here to switch it off, enemy switch the core wall owns by clicking here and clicking Apply. We can see that we only have the grades for the core if we are working on modeling the core, for example. And then we can switch it back off and go back to the building grid. And let's click OK here. So far that's not very handy. The actual benefit of it comes when you want to work with elevations. So for example, if I wanted to open one of the core elevations over here, Let's switch back our grid on for the core. And let's say I wanted to look at this elevation, which is the core grid elevation a. I can jump into my 3D. Click anywhere to activate it and click on the elevations at elevation view. And I can basically click core. And then that's my core grids. And I want to look at the elevation of a, and straight away I have the elevation of this core wall. Now if I wanted to look at the building elevation instead, say for example, the one over here. If you click on it, you can see it says this is one k. We know this is a great k. So in this direction is one. So we can say building one. And we can click here to activate it and click Apply. And there we go. We have the grit, one of the building. So that's very easy to work. And elevations where the walls, in terms of adding openings, looking at stresses and anything like that. But that's not all as well. So another trick is when you are modelling the slabs, this can be complex. So what do you can do here? If you go down to the bottom right-hand side, you can actually change the layout from being oriented to the global. You can orient it to the core, which in this case is a 0 degree because it is matching the global orientation. But if I match it to my, sorry, you can't see this. Let me move it up a little bit. But if I actually choose to match it to my g2 of the building. There you go. We have the building orientation now at True North and that makes it much easier when you modelling and you're cutting and you're assigning stuff. And it's also easier to see if this is how you have it on the growing as well, for example. Now one last trick that it's quite helpful when you're working with grids. Say for example, now I have this grid. I have this precast wall over here that I want to look at elevation. And the only way to look at the elevation of a wall is if you have a grit for it and then you can open it. So especially that it's coming at an angle. It's not really perfectly horizontal to any of the two grids. The only way to do it is to actually draw a great manually and I'm going to show you how to do that. So if we switch on our joints first by making them not invisible. And then if you go to draw grids, and then this is a building, great. So I'm going to choose their own growing in my G2. And then I'm going to choose the starting point of the grid. And I'm going to choose the end point of the grid. And there you go. It's called up as one. But in the main building grit, I already have great one and e-types doesn't recognize that. It just adds it as a user grid. So we'll need to go and edit its name manually to be easily reference in the future. So I can go to Edit, edit my grades. I can edit my building grids, click Modify and show the system. And then in here you can see that the grids that you user, User Defined or manually define it comes at the bottom. And you can actually change this to. Say this is precast one grid for example. And I'm going to click Okay. And we're going to click Okay. And you can see its name here has changed. So if I go to the elevation on the right-hand side and I want to open up the elevation of this wall now and click P1 and click Apply. You can see now this is my precast and it's shown here. And I can actually see the intersection with the other grids if I click here, right-click. So the grid system visibility and switch on my building grids. And click Okay. And click Okay. You can see, I can see the flow level. I can see my three grids that the world is crossing here. Actually it's not really three, I think is just two. And if I zoom in, this is the intersection with great line one, which is this vertical grid line. This is the intersection with grid line J, which is this horizontal grid line. And this is the intersection with migrate line 1, B, which is this internal line. So it shows you the intersection basically where the grids in both their actions in case if you wanted to split it at the grid, for example, which is quite common. If you have something that you want to join that the grade you can easily select the wall. You can go to Edit and divide your shell. So you can go to edit shells, divide shells, and you can choose to break them down at the selection with the grids initial click apply. You'll see that your wall now is broken down at this intersection. Let's say you only want to break it at only this grid. You can easily select these two. You can delete them. You can select this one and you can go to the tool on the left here, which is the reshape tool. And we can use the reshape to select this one and click here, extended and snap to the point at the top. And there we go, we have created the breakup application. And we can break up the floors below by using the divide add selected joints on the edge. And we can break up our wall of dislocation for example, either for better meshing or for other purposes. Actually, I'm at the wrong floor here. I've broken it down a level seven and level 6, so let me go down. Yep, there we go. We see that it's broken down here. Let's say for whatever reason you want it to measure slab here or the wall is stopping and you want a better mesh accuracy, you definitely want to match the precast where there is discontinuity like this as well. But that's a side topic. So I hope you've got the point from this video today which is basically seeing the grids use the different angles and different orientations and they're used for different purposes. You can have as many grids as you want an E tabs. And the purpose is really just to enable you to model and look at the results of different components quite easily compared to just having one big grid or actually not having grids at all, which makes it more difficult. Because you can only see the results in 3D in this case. That's it for this one. See you in the next video. 40. Piles Vs Pins: Hello and welcome again. In this lecture, we're going to be going through a question that was raised whether we should be modelling in our piles in the building or should we just have the raft has been supported? So first let's have a look at this building. So this building is an actual project that I'm working on. And in this building, I actually have the piles modeled in the raft slab model then in the basement and at the base of the piles. These are the support points with their actions. Modelling in the raft is pretty much similar to modelling a slab. And modelling in the pulse is pretty much like modelling the columns. So it's fairly straightforward. As long as you have the slab, which is they're off modeled correctly and you have the piles modeled correctly. You can easily get the reactions at the base of it. And if you click on this playing their actions, you should be able to see, for example, your vertical reactions here below these, these piles. Now, how about if you model it as a pin support? So let's look at this alternative model. And what I'm going to do is I'm going to select all of these nodes. And one by one, I'm going to assign them a pin support. And now I'm going to set my view limit to the raft that I'm working with right now. And this way, I can quickly just select my columns and delete them. This probably a faster way of doing this. Let's say if I rotate my model and look at it from the side. For rotated a little bit more. I should be able to see only the piles and I can select them quickly and I can just delete them. So now in this model, instead of having the columns, I have all of my column positions assigned the pins of ports except these ones which I'm going to assign now. Okay? What I can do as well is because I've got these tiff regions at the center of the pile caps where the nodes were not added for support. I can manually do that. So after I can select them, I can divide them into a two-by-two. That's gonna give me the center point as you can see. And then I can select the center point and give it the support. Okay, now that I've got all of my nodes in, I'm going to rerun the analysis and let's compare the results between the two. The case that we just had our analysis finished running now. And we can compare the result of the pin supports into the draft as on the right-hand side. Compared to the columns modeled in. Generally, there is a little bit of different distribution as you can notice. And that is, as you can see here, this node, this internal central node, is actually attracting a huge load now. So it's 3,755 mil while it was only 3,100. Similarly, this one is 3500 when before it was only 3000. And the other nodes that were at the corner. So these external loads, the loads have actually reduced and more LOL has been distributed to these internal nodes. So the question is what does happen when we have it as a pin support compared to when we had that as a pile or as a column. The difference lies in stiffness. Okay? Understanding that the boundary conditions you define in your model has a significant impact on the results. In high-rise buildings generally is very, very important. When you put it as a column, the column can compress. So the pile can compress. And when you have a huge pile reaction like this, 13,100 and the adjacent pause has lower loads. What happened is when you have 1.2 meter the prophet, like in this case, the rafter has enough strength to redistribute some of this vertical load into the neighboring piles. And It's not even going to be working hard with redistributing these loads. So when you model in the column, any modelling the boundary conditions correctly. Etags uses the stiffness of the raft and uses the compression capacity of each column to work out how much load is going to be distributed between the pulse. But in the right-hand side, when we had only pin supports, pin supports are infinitely stiff. They don't deform, they don't compress. So what it taps give you is just the analysis of the building. It doesn't actually take into account that these columns are, these paths are going to compress. Under such a huge load. The load will be redistributed to the adjacent pulse. It doesn't take that into account when you put it as a pin support. So you have to be careful with the assumptions that you make and are always recommend to modelling the paws like what I've done on this real life projects on the left-hand side. This way, you have the correct boundary elements and you have the correct considerations taken into account in your building analysis. And it's actually easier because now once I've finished running my analysis over here on the tabs, I can export this floor to save. And I can get my world reactions. I can get the bending moments from thereafter, including the redistribution of the load between the poles. And I can straight away does Ionic and safe on the right-hand side where I didn't have my piles in. I will actually be on the estimating the raft because thereafter is going to help you to distribute the load into the adjacent piles like what we've seen on the left-hand side. And when you don't take that into account, you actually end up with the walls doing all of the work, distributing all of the load than to the piles. And thereafter not being designed for the correct forces. I hope that answers this question and you've learned something from it. Thanks and see you in the next video.