How to Design High-Rise Buildings
- Zeynep Aladağ
The design of high-rise buildings is made in 3 design stages within the rules given in TBDY Chapter 13 . If your building is Hn = 130m, it is defined as a tall building and classified as BYS = 1. You can also see this classification from the TBDY Wizard in ideCAD.
In TBDY Chapter 13 , it is said that 3 stages should be done for high-rise building design.
In the first stage , the KH performance target is to be achieved with the DGS approach to the DD-2 earthquake level. This type of analysis is the analysis based on Chapter 4 and Chapter 7. In the program, it is the normal analysis used for all types of buildings. When the building model is defined appropriately, the results are obtained automatically. You can easily do this step in ideCAD. Here the results will give the same results as other international programmes.
The second stage should be evaluated for a DD-4 or DD-3 Earthquake Uninterrupted Use Under Ground Motion or Limited Damage Performance Target. There is no automatic definition in the program for this stage. For the second stage calculation, linear analysis can be done with modal calculation methods in the normal performance target. However, for this, you have to define all the conditions stated in 13.5.3 yourself. Taking R = D =1, DD-3 earthquake level definition, spectrum curve change given for damping rate…
For the third stage performance target, nonlinear analysis in the time history should be applied. Since the details are long, I do not write them here one by one, but you can review them from TBDY Section 13.6 . In ideCAD, there is no nonlinear analysis option in the Time History field. However, scaling of earthquake records to be used for nonlinear analysis in time history can be done in ideCAD. Nonlinear analysis in ideCAD is done by push analysis, but TBDY does not accept this method for high-rise buildings.
In the light of what I have written, the first stage of high-rise buildings can be easily done in ideCAD. There are some constraints for the second stage here. For the third stage, there is no nonlinear analysis in the time domain.
This 3-stage account is also valid for other programs. For example, if it is to be done with ETABS, 3 different models should be defined and all conditions given in Chapter 13 should be applied.
We had a detailed webinar training on tall building design. You can watch this training in the video below. Detailed explanation of all the issues I tried to mention above and the place of regulation are in this training.