【摘要】 选择合适的地震动记录是采用弹塑性时程分析预测建筑结构地震响应的基础。列举了现有针对不同分析目的的三种地震动记录选取方法,比较了按不同方法建立的地震动记录选择集的地面运动峰值和反应谱特性,并通过分析两个不同初始周期框架结构的弹塑性地震响应,对不同地震动记录选取方法的分析结果进行了比较。研究结果表明,基于设计反应谱和基于最不利地震动的选取方法均与结构的初始周期相关,当结构在地震作用下刚度退化比较明显时,这些方法有可能难以达到预期的目标;而当地震动强度指标恰当、且选取的地震动记录数量较多时,基于台站和地震信息的选取方法不会造成过大的结构弹塑性地震响应的离散性,同时这种方法不依赖于结构的动力特性,操作简便,适用性强,适于在研究不同结构类型和不同动力特性建筑结构的抗震性能时应用。更多还原

【Abstract】 Careful selection of earthquake ground motions forms the basis for performing nonlinear time history analyses of building structures.Different methods of selecting earthquake ground motions should be used in accordance with the purpose of the time history analyses.The applicability and applicable conditions of typical selection methods are discussed.Features of the earthquake ground motion sets established by different methods are compared in terms of the ground motion peak values,frequency contents and nonlinear seismic responses of building structures.The results show that the method based on design spectra and the method based on most-unfavorable earthquake may sometimes be unable to fulfill the aim of the selection due to their dependency on the initial vibration period of the structures,especially when the structure suffers significant stiffness degradation during the earthquake.On the other hand,the earthquake ground motions selected by the method based on the station/earthquake information would not induce unacceptable scattering in the nonlinear seismic responses of the structure given that appropriate earthquake intensity index is adopted.This method is simple and widely applicable for its independency on the dynamic characteristics of the building structures,which makes it favorable in studying the seismic performance of building structures of various types and dynamic characteristics.更多还原