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Floor Spectra of Base Isolated Structure

Thread starter bladeyus
Start date Jul 13, 2016

Status: Not open for further replies.

Jul 13, 2016

bladeyus

Civil/Environmental

I am continuing structural/nonstructural design of a base isolated structure. Time history analysis (3D) gives reasonable results, however when i try to obtain the floor spectra there are sharp peaks (around 1 g whereas average acceleration is about 0.2 g for other periods other than resonance frequency of the structure/isolators) at periods around 0.04 sec and 0.125 sec. Note that those peaks do not happen for the records with only horizontal excitation. I am investigating the results for the floor just above the isolators. Does anyone have any ideas/recommendations/explanations?

Thanks in advance,