Influence of seismic fragility analysis of RC frame structures under ground motion records selected and spectral matching via equivalent period of structures
It is the fundamental issue to choose the appropriate intensity measures(IMs)and ground motion records for seismic fragility analysis of structures.First,2 suites of 20 ground motion records were respectively selected based on spectral acceleration corresponding to the fundamental period of the structure Sa(T1)and spectral acceleration corresponding to the equivalent period Sa(Teq).And these ground motion records were spectrally matched to the targeted design spectrum.Then,incremental dynamic analysis(IDA)was respectively conducted on a 5-storeyz&11-storey reinforced concrete(RC)frame structure model under the aforementioned 4 suites of ground motion records.Influence of spectral matching method and different IMs were analyzed on maximum inter-story drift ratios(θmax)and seismic fragility analyses,maximum residual inter-story drift ratios(RIDRmax)and collapse margin ratio(CMR).The analytical results indicate that under the 2 suites of spectrum-matched ground motion records,the dispersion of seismic fragility of structure was significantly reduced.And the dispersion of Sa(T1,5%)and Sa(Teq,5%)corresponding to the 50%exceedance probability for each damage state were no obvious biases.With the increase of structure damage states,Sa(Teq)as an IM can more effectively reduce the dispersion of seismic fragility analysis results.With CMR as reference indexes,selection of ground motion records with Sa(T1,5%)as an IM may overestimate the structure collapse resistance,consideration should be given to Sa(Teq,5%)for better IM.
万方数据
维普
