ponding

[broncosfan]

Hi

AISC has two design procedures for ponding. One is for a case where there are flexible primary and secondary members. The other is for when there are flexible secondary members bearing on a wall (infinitely stiff primary member: Cp=0)

What happens if you have roof joists bearing on a flexible joist girder at one end and a concrete wall panel at the other end? Let's say the water is going to pond at the concrete wall. Do I follow the procedure that assumes the primary member is infinitely stiff? Or do I maybe assume the primary member stiffness (Cp) is an average of the joist girder stiffness (Cp=x) and the wall (Cp=0)...i.e. Cp=x/2.

Thanks.

 

[JAE]

I'd do your latter suggestion - run both analyses and know that you fall between them somewhere, probably half-way.