I am performing Pushover Analysis for steel structure using STAAD Pro 2007.
The structure comprises of Special Moment Frame in X direction and braced frame in Z direction as seismic force resisting system.
I have some basic queries regarding input parameters in Pushover Definition.
(1) Define Gravity Load: Usually, we define gravity load in -Y direction in STAAD. However, I have applied gravity load in +X direction (as my seismic load is in X direction) as mass in X direction. Is this correct or I have to apply load in -Y direction?
(2) Define Load Pattern: I am selecting AUTO load pattern from the tab. This asks me to enter value of base shear (V1) to be distributed (it also says that if I don't define the value, STAAD will assume 10% of gravity load). I understand that the base shear value, V1, should be the value calculated from Equivalent Lateral Force Procedure. Is this correct? In Define Solution Control, it asks to input the value of base shear (V2) up to which the structure should be pushed. Say for example, I enter V1= 3000 kN (calculated base shear); if I enter V2=V1, then the programme will be terminated stating that calculated base shear exceed specified base shear. Please advise on the values of V1 and V2 to be entered.