Seismic Question - WSP Diaphragm Nailing Spacing

[singrasj]

Hi,

I am going over old practice exams for seismic and I can't seem to understand how the N-S distributed load is used to determine the distributed shear load for the W-E direction. Also, I dont understand when the question asked to find the nailing requirement for along the diaphragm boundaries, but uses the E-W distributed shear load. Any Ideas?

Thanks!

 

[Schmitty]

This problem is not asking about E-W loads. The N-S distributed load is being turned into a point load that is split between the two ends of the 80' side (this is done for flexible diaphragms). The resulting 24000 lbs is converted to a unit shear (SD) along each boundary in the N-S direction, then an allowable stress design (ASD) factor is applied. The force occurs at the E-W ends of the diaphragm, but it is the N-S distributed load that is being used for the calculation of unit shear in the N-S direction.