Effective Seismic Weight 1

[VAStrEngr]

When determining the effective seismic weight, ASCE 12.7, do you include portions of the building isolated from the seismic force resisting system? For instance, in a one story building with a floor slab that is isolated from the outside walls (shear wall system) is it necessary to include the weight of the slab + equipment into the calculation of W? Although the definition given says to include weight of permanent equipment, this seems unnecessary if that weight isn't being transferred into the lateral force system.

 

[MiketheEngineer]

I agree

 

[Qshake]

If you are talking about the floor slab on the ground that is independent of the walls - then yes. If there is another floor slab slight above the ground which adds weight to the walls vertically but is not connected for lateral reasons - I don't think I'd neglect it entirely.

Regards,
Qshake

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[weab]

Vas,

You've got it right.

 

[Modes]

Make it simple.Include the weight of all those components which will experience inertial force because of the movement of slab above base.In one storey building any compoment isolated from roof and columns will not experience any inertial force.