I need clarification about this,
If a building model includes wind load
1.During load combination,i must use repeat load combination,why repeat load combination?
2.During Analysis i must use P Delta Analysis,why P delta analysis and not normal analysis?
3.During beam and column design in RCDC,if i put load combination from regular structure,how does RCDC design beam considering different load combination which exist
a) dead load + imposed load
b) dead load + wind load
c) dead load + imposed load + wind load
Will it design for each load combination which exist separately and provide detailing for the worst case,or it will design for each case and combine the design detail.
Because each case will give different moment and shear in beams and columns
Hello,
I am not sure why you are thinking that if wind load is considered you need to use repeat load and p delta analysis. To clarify your thoughts I would recommend to refer below links and take the decision.
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/29299/difference-between-a-load-combination-and-a-repeat-load
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/22312/p-delta-analysis-with-verification
During design in RCDC, the program will find out the most critical case and will provide output on basis of that.
After watching this elaboration, i have attached the link
learn.bentley.com/.../ViewLearningPathDetails
then i thought when we have a vertical load acting on a building together with horizontal load which in my case is wind,i should do repeat load combination,and my analysis has to be p delta analysis
?
Abhisek M please when you get time,i would need your help to demonstrate for me, now iam confused because on OnDemand Video they had to perfom P delta analysis when vertical load together with vertical load exist in a model
Hi Joseph,
I guess you have gone through the wikis I pasted above. The essence of p-delta is now clear to you. Yes, the example you are pointing is a scenario where you can use P-delta analysis. But it depends on the design codes or guidelines if yu really want to include that second order analysis in your model. For example, there are few codes (like IS800 2007) which provides some relaxation in the form of a multiplication factor upto certain criteria and after that P-delta is required.
Ideally you can use P-delta in every structure but that may incur a lot of time with a very little change in output. So, in practical cases you may ignore p-delta for smaller structure but if you are delaing with tall structure it is mandatory.
Thank you,one more question what is the minimum size(height) of a building that has to be considered as a tall building in Staad Pro so as i can perfom P Delta Analysis