脉冲型地震下地震动强度指标与基础隔震结构位移响应相关性研究

以隔震结构等效SDOF体系为研究对象。采用Bouc-Wen模型描述体系非线性力-变形行为,以近断层脉冲型地震记录为输入,运用MATLAB进行编程并求解得到体系的非线性地震响应;采用Spearman秩相关系数法对地震动强度指标与SDOF体系位移响应之间的相关性进行统计研究;分别以5层和8层基础隔震结构为例对分析结果进行算例验证。研究结果表明,与其它地震动强度指标相比,速度型指标在各周期段均与等效SDOF体系地震位移响应呈现较高相关性;各地震动强度指标对应相关系数曲线的分类化特征明显,其中对应第1类曲线的地震动强度指标更适于多层基础隔震结构,建议将VSI或HI作为优选指标用于多层基础隔震结构地震位移响应预测等相关方面研究。

Correlation between ground motion intensity indexes and displacement responses of a base-isolated structure under pulse-type ground motions

Here,a single-DOF(SDOF)system equivalent to a based-isolated structure system was taken as the study object,Bouc-Wen model was used to describe the system nonlinear force-deformation behavior,near fault pulse-type ground motion records were taken as input,and nonlinear seismic responses of the system were computed using the software MATLAB.Spearman rank correlation coefficient method was used to statistically study the relevance between ground motion intensity indexes and seismic displacement responses of the SDOF system.A 5-floor base-isolated structure and a 8-floor one were taken as examples to verify the analysis results,respectively.The study results showed that compared with other types of ground motion intensity indexes,velocity-type ones have a higher relevance to the equivalent SDOF system’s seismic displacement responses within each period;correlation coefficient curves corresponding to various ground motion intensity indexes have obvious classification features,and the ground motion intensity index corresponding to the 1st type curve is more suitable for multi-story base-isolated structures,VSI or HI is recommended as an optimal index to be used inpredicting seismic displacement responses of multi-story base-isolated structures.