基于能力谱法的SSI体系抗震pushover分析方法

本文首先经过2次等效将土与结构相互作用的多自由度体系等效为单自由度体系,并给出了修正反应谱和等价能力谱的确定方法,进而提出了基于能力谱法考虑土与结构动力相互作用(SSI)效应的结构体系pushover分析方法(SSIPA);然后对3种不同高度考虑SSI效应的结构体系在5条地震动作用下采用本文提出的方法进行了算例分析,将结果与非线性时程分析的结果进行了比较,研究了本方法的适用性和准确性;最后,与建筑抗震设计规范的设计反应谱相结合,对9层考虑SSI效应的钢结构用本文提出的方法进行了弹塑性地震反应分析,根据我国抗震设计规范的规定进行抗震性能的评估验证了本方法的可行性。

Pushover analysis procedure for system considering SSI effects based on capacity spectrum method

In this paper,through twice equivalence,an SSI system can be transformed into an equivalent SDOF system.Then the pushover analysis procedure based on the capacity spectrum method for system considering SSI effects(SSIPA) is put forward on the basis of an equivalent SDOF system,and modified response spectrum and equivalent capacity spectrum are given.Furthermore,three different-height steel buildings including SSI effects used as examples are analyzed under two far-field and two near-field historical records and an artificial seismic time history.The results obtained by nonlinear response time history analysis(NL-RHA) are treated as exact' solutions and are compared with those obtained by SSIPA procedure.In addition,the accuracy and applicability of the proposed procedure are discussed.Finally,the nonlinear seismic response of a 9-storey building with SSI effects is analyzed using SSIPA procedure combined with seismic design response spectrum,and the seismic performance of the building is evaluated depending on the code for seismic design of building.The feasibility of the proposed procedure is verified.