Stiffness Reduction - Sustained Load

[Lazzaroni]

Can someone clarify the Beta-d factor for reducing the member stiffness due to a sustained lateral load per ACI-05 10.11.1 for a non-sway frame?

It states that Beta-d is the ratio of maximum factored axial sustained load to maximum factored axial load associated with same load combo.

Is the sustained loading simply dead + sustained lateral load?

Thanks

 

[Lion06]

I would probably add in something along the lines of 20% LL (maybe a little higher if partitions are included in LL).

 

[NewImhotep]

usually it is (DL+0.25LL) / (DL+LL)