Etabs Modeling

[Arman79]

I am using ETABS for modeling an irregular multi-story structure. Seismic load lateral system for the structure is a dual system consisting of special moment resisting frame and special concrete shear walls.
I am using automatically generated seismic loads as per UBC 94 for static loads and I am also conducting response spectrum analysis for the structure. I have faced a problem.
Actually, the weight that is used by the software to calculate base shear for the structure is not consistent with the mass of the system that is reported. The mass is much less than what it should be compared to the weight of the structure. I have noticed that the problem arises from shear walls. Indeed, mass of the walls are not correctly incorporated in the calculation of mass of each diaphragm.
I would be grateful if any comment can solve my problem.

 

[prsconsultant]

Post your ETABS model

 

[jenofstructures]

go to the DEFINE then to the "mass source"
on the mass definition pick "from loads" then pick the dead load

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