Seismic Fragility Analysis of High-Strength Concrete Filled Steel Tube Column-Aluminum Alloy Buckling Restrained Braces Structure System
In order to study the failure probability of the high-strength CFST-aluminum alloy core assembled buckling-restrained braces(HSC-SB-ALAB)under different intensity of ground motion,based on the incremental dynamic analysis(IDA)method,the near-field pulse ground motion,far-field ground motion,near-field ground motion and integrated ground motion were selected.The seismic fragility of a 10 story HSC-SB-ALAB is analyzed by using four groups of 45 strong motion records.The fragility curves of the structure under four earthquake types are obtained;the probability of reaching each limit state of the structure under frequent earthquake,fortified earthquake and rare earthquake is given;and the collapse margin ratio of the structure is calculated and evaluated.The results show that the probability of reaching each limit state is the largest under the action of near-field impulse ground motion,and the exceeding probability is the smallest under the action of far-field earthquake.Under the action of various types of ground motions,the collapse probability of the structure is only about 1%,which meets the seismic fortification goal of"no damage in small earthquake,repairable in medium earthquake and no collapse in large earthquake".The collapse reserve coefficient is greater than the minimum value of 2.47 required in FEMA P695,which is 1.34-1.43 times that of other types of concrete-filled steel tubular structures.
high strength materialsconcrete filled steel tubeBRBIDAfragility analysis
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万方数据
