近断层地震动对基础隔震结构地震反应的影响

摘要

采用OpenSees对基础隔震结构进行了不同类型地震动作用下的地震反应分析,研究了近断层脉冲型地震动及其特性对结构地震反应的影响,表明近断层脉冲型地震动对基础隔震结构的地震反应有较大影响,甚至可能造成支座由于水平变形较大而导致其破坏,使基础隔震结构的隔震效果有所降低;在罕遇地震作用下,结构的地震响应随近断层地震动的PGV/PGA和PGD/PGA的增大而明显增大,其中PGV/PGA和PGD/PGA对支座位移的影响最大.因而,在近断层区域进行基础隔震结构设计时,应重点考虑地震动的脉冲效应对结构地震反应的影响.%The analysis on the the seismic responses of the base-isolated structure under different ground motions is carried out by using OpenSees.The infulence of the near-fault pulse-like ground motions and the characteristics on the seismic responses of the structure is studied.The results show that the near-fault pulse-like ground motions have significant effects on the seismic responses of the baseisolated structure.The bearings may be destoried because of very large displacements induced by the near-fault pulse-like ground motions,so the isolation effect of the base isolated structure will be reduced.Under the rare earthquake intensity,the seismic responses of the structure increase with the increasing of PGV/PGA and PGD/PGA of the near-fault pulse-like ground motions,in which PGV/PGA and PGD/PGA have the greatest influence on the bearings displacements.Therefore,the influence of the pulse effect of the near-fault ground motions on the seismic responses of the structure should be considered in the design of base-isolated structure in the near-fault area.