主余震序列型地震动对RC框架结构地震反应定量影响研究

Quantitative influence of mainshock-aftershock sequence ground motion on seismic response of RC frame structure

为探讨主余震作用下结构地震反应特征,量化主余震序列型地震动对结构地震反应参数的影响,采用OpenSEES有限元软件建立了一个3层典型RC框架结构模型,并选取594条实际台站记录到的真实主余震地震动记录作为结构反应分析的输入激励,开展了结构地震反应计算,分析了余震与主震相对强度、场地条件和地震动输入强度对结构地震反应的定量影响.结果表明:余震地震动对结构地震反应影响显著,最大可达90%,余震地震动对结构响应影响程度与其对主震的相对强度相关性较大,与场地条件相关性较小,规律不明显,余震强度对结构地震损伤影响明显.本文结果可供考虑主余震作用的结构抗震设计参考.

In order to evaluate the structural seismic response under the action of mainshock-aftershock and quantify the influence of aftershock on structural seismic response parameters,a typical 3-story RC frame structure was numerically modeled by using OpenSEES software,and the seismic response under the excitation of 594 actual mainshock-aftershock strong motions was performed and analyzed.The influences of relative strength,site conditions and ground motion input intensity on the calculation results are discussed according to analysis results.It is found that the aftershock earthquake has a significant influence on structural seismic response,especially on the seismic damage state.The influence of aftershock earthquake on structural response is mainly related to the strong motion relative strength,but has low correlation with site condition.The results can be used as a reference for seismic design of structures considering mainshock-aftershock effects.