Dynamic analysis and Inter storey drift limits 2

[ramsha]

I have completed the response spectrum analysis and have done the scale up as per UBC 1997 1631.5 and found that the base moments and deflections are less than the static elastic analysis. my interpretation is that As per UBC 1997 I am allowed to use the results from dynamic analysis.

Is this correct?

 

[Taro]

Base overturning moments and deflections are usually lower for dynamic analysis than equivalent static analysis. This is because the static procedure uses a conservative first mode applied load to envelope the effects of higher mode response. Dynamic analysis explicitly considers the higher mode effects so the conservatism of the static procedure is eliminated. So, yes it is appropriate to use the lower moments and deflections from the dynamic analysis as long as the analysis is performed properly and scaled as required by code.

 

[ramsha]

Thanks Taro.
ramsha