I've got a set of R/C spandrel girders running parallel to a cast-in-place
concrete joist floor. The code tells you the effective flange width, and my
young engineer "assumed" that this is also the width of live load carried by
the girder. Obviously that's not the case.
But it brings up the question of just how to determine how much live load to
distribute to the girder itself. This is a question of no small consequence,
especially since live load actually HELPS this girder against stress
reversals at the column joints when lateral loading is considered.
I'd like some opinions: How much of the live load on a joist floor can I
distribute to the parallel spandrel girder?