Regarding the analysis based on wind and earth quake..

Question

Sir very good mrg....I just wanted to know why I am getting vertical load that is Pu=501kn If I do the analysis by just the load condition Deadload and Live load and I am getting vertical load as Pu=-3.14kn if I am doing analysis by Dl +LL including wind and seismic.

Abhisek M · Answer

Dear User, 
 If you want to compare the results of 2 files you need to use identical inputs for both the files. The dead & live loadings in the files are completely different. Please make sure you use the same load for both the files. On the other hand, reactions due to only gravity load (DL & LL generally) will not be the same for load combinations with lateral loads like seismic or wind as there will be tension, compression situation in the columns.

Abhisek M · Answer

No, that is not the correct idea. Due to lateral loadings there will be tension and compression in structure. Depending upon your combinations and loading pattern the columns subjected to compression will give higher reaction and columns subjected to tension will give lower reactions.

Abhisek M · Answer

https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/42755/warning-in-staad-pro-output-file-length-to-depth-ratio-is-less-than-2-5 
 https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/144011/warning-length-to-depth-ratio-for-members-is-less-than-2-5-and-ensh-1-parameter-doesnot-able-to-remove-the-warnings

Abhisek M · Answer

You can find example files in the following path of your system. 
 C:\Users\Public\Documents\STAAD.Pro CONNECT Edition\Sample Models