隔震结构等效线性模型的反应谱法研究

Study on response spectrum method based on equivalent linear model of isolated structures

减震系数法作为传统的隔震结构计算方法,是将隔震结构等效为降度后的抗震结构进行反应谱分析,该方法无法真实地反映隔震结构的变形及受力状态。采用反应谱法对基于隔震层＂等效刚度＂和＂等效阻尼＂的＂一体化＂模型进行分析,通过三种常用结构体系的模型算例,对比反应谱法与时程分析法的计算结果,以研究用反应谱法分析带隔震层的＂一体化＂模型的适用性。研究表明,在隔震层弹塑性行为较为明显时,反应谱法可能低估隔震结构上部楼层的剪力,导致结构设计的不安全。

As a traditional method for calculating the isolated structure,the damping coefficient method is to analyze the response spectrum of the seismic structure after reducing seismic fortification intensity with the equivalent of the isolated structure.This method can not truly reflect the deformation and stress state of the isolated structure.The ＂ integrated＂ model based on the ＂ equivalent stiffness＂ and ＂ equivalent damping＂ of the isolation layer was analyzed by the response spectrum method.The model examples of three common structural systems were used to compare the response spectrum method with the time history analysis method.The calculation results were used to study the applicability of the ＂integrated＂ model with isolation layer by reaction spectrum method.Studies have shown that when the elastoplastic behavior of the isolation layer is more obvious,the response spectrum method may underestimate the shear force of the upper floor of the isolated structure,which results the unsafe of structural design.