mrengineer
Structural
I am doing design of 2-story post-tensioned garage, using ADAPT-PT for the beams. I am using RISA-2D for frame analysis to obtain lateral load moments for ADAPT and for column loads. I am coming up with huge column moments in the RISA runs, and it is apparent that I need to take advantage of the secondary effects of post-tensioning to reduce the column moments. My question is how do I do that exactly? Do I take the end moments from section 9.7 of the ADAPT output (what they refer to as "balanced moments") and then input those into the RISA frames as beam end moments? Any advice on how to approach the column design and reduce the moments would be greatly appreciated. I am currently using 24"x24" columns, and hate to have to go back to the architect at this point and tell them I need bigger columns.