RAM | STAAD Forum - STAAD BASE SHEAR ISSUE IN RESPONSE SPECTRUM METHOD (CQC) IS 1893 (Version 22.03.00.28)
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STAAD BASE SHEAR ISSUE IN RESPONSE SPECTRUM METHOD (CQC) IS 1893 (Version 22.03.00.28)

BCL
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Bentley Communities Legacy Member
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Created (Edited ) in RAM | STAAD Forum

I have made a  two  test model for the response spectrum analysis which is attached herewith, i have two questions,

 

1) TEST MODEL 1:  When I have specified the Seismic response spectrum (IS 1893)  as per below where damping is 2% for steel

 image

 

2) When I have given the Seismic response spectrum (IS 1893)  as per below where damping is 5% for & multiply by coefficient by 1.4 ( for 2% steel as per code) 

 image

Question 1: Then Why there is difference between CQC base shear ? & all others base shear matching  

image

I have checked the Time period / participating factors /shear  its same for both model but difference in base shear so its reflects in unity ratio  for steel design .

Question 2 : I have prepared Portal frame applied loads & do the same procedure as per above then Base shear /unity ratio is exactly matching.

Anyone getting same issues ?

Regards,

Amol

 
Topics: STAAD BASE SHEAR ISSUE IN RESPONSE SPECTRUM METHOD (CQC) IS 1893 (Version 22.03.00.28)
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