地震动记录选择与调整对RC框架结构地震响应影响研究

Investigation on selection and modification of ground motion records for the influence of seismic responses of RC frames

合理的地震动记录选择与调整是影响结构非线性时程分析结果可靠度的重要因素之一。选择7组地震动记录分别运用谱匹配方法和按结构基本周期对应谱加速度S_a(T_1)调整方法进行调整,并分别对5层和11层钢筋混凝土平面框架输入调整后的地震动记录,进行单一强度水准下的非线性时程分析,提取结构最大层间位移角和最大残余层间位移角为工程需求参数进行了离散性分析和偏差研究。分析结果表明,选择合理的地震动记录进行调整和对目标谱的匹配可以减小结构地震响应分析结果的离散性,且响应分析结果不会出现较大程度的偏差;相同强度S_a(T_1)下,结构地震响应分析结果随条件谱谱形参数ε的增大而减小。

The reasonable selection and modification of ground motion records is an important factor for the reliable nonlinear time history analysis results of structures. 7 groups of ground motion records were selected and modified by spectral matching and spectral acceleration corresponding to the fundamental period of the structure S_a T_1). Then,a 5-story and an 11-story planar reinforced concrete frames were analyzed via nonlinear time history analysis method with a single intensity measure under the spectrum-matched and modified ground motion records respectively. Maximum interstory drift ratios and maximum residual inter-story drift ratios of the structures were taken as engineering demand parameters( EDPs) and the dispersion and bias of EDPs were also discussed. The analysis results show that choosing reasonable ground motion records to be modified and matched with the target spectrum can reduce the dispersion of the structural response results without conspicuous bias. With the same intensity measure S_a(T_1),the analytical response results of the structures will decrease with the increasing of spectral shape parameter ε of the condition spectrum.