采用结构等效周期的强地震动记录选取方法

摘要

The common ground motion selection method based on the design response spectrum does not consider the elastic-plastic properties of the structure,which causes the poor adaptability for strong ground motion selection.This paper improved the method by introduce the concept of equivalent period.For structures reaching the elastic-plastic state under major earthquakes,the improved method use capacity spectrum method to work out the equivalent period Teq,and control the deviation of seismic response spectrums to select the ground motions.We build a ground motion database and program to select ground motions using the common method and the improved method respectively.Nonlinear time history analysis for a frame structure was conducted which verified the obvious effects of the improvement.%普通的基于设计反应谱的地震波选取方法并未考虑结构的弹塑性发展,难以适应罕遇地震下结构非线性时程分析的地震动记录选取.引入结构等效周期的概念对目前广泛使用的选波方法做了改进,针对罕遇地震下进入弹塑性状态的结构,通过能力谱法估算其等效周期Teq,再控制Teq附近周期段内反应谱的偏差选取地震波.基于样本丰富的地震波数据库编制程序,分别通过普通选波方法与改进的选波方法进行地震波选取,并对一个框架结构做了非线性时程分析,验证了方法对强地震动记录选取具有良好的适应性.