Etabs 2013 - ASCE-10 Base Shear Different from Hand Check

[lostit40]

I am using ETABS 2013 to run an analysis on a 5 storey precast bldg. I wanted to use ASCE 10 equivalent method to develop the base shear on the structure. The problem is I calculated the base shear around 720 kips and ETABS is registering 220 kips. I looked at the parameters and I have in all the factors (R, omega & Cd) correctly. I really do not know what I'm doing wrong.

 

[frameingineering2014]

Please check the mass source.

 

[sponton]

yes, what is the weight of your building, is etabs taking Dead loads only, self-weight of members? what are you including in the weight of the building?

 

[Backcheckrage]

Go to View Tables -> Auto Seismic Loading Per XXX -> check your mass, building period, and seismic coefficient used in the automatic calculation. Also, ensure you have specified properly your "Mass Source" to include whatever you want the seismic calculation to see.

 

[lostit40]

thank you newzealandengineer that worked!