Seismic Irregularites

[ToadJones]

Is anyone familiar with a procedure for determining the "story lateral strength" as covered in ASCE 7-05 and more particularly in Table 12.3-2 in ASCE 7-05.
This definition seems very vague to me.

 

[WillisV]

It depends on the structural system - for dual systems or shearwall systems the concept of story strength is very difficult to define. For a moment frame type system, you can calculate the strength required to form a story plastic hinge mechanism (for example for steel see the commentary of section C of the seismic specification for a method that would be acceptable for this kind of check - the same basic premise would work for a concrete moment frame as well).

 

[ToadJones]

Willis-
Are you referring to the SDM?

 

[WillisV]

Seismic Design Manual - in particular commentary to AISC 341

 

[ToadJones]

Yes, I was looking at 341-05, can you point me to a page?