基础隔震结构的长周期抗震性能分析

摘要

In order to study the long period seismic performance of base isolated structure,a total of 18 near field and far field ground motions are selected as the external incentive according to the current method for defining the long period ground motion,the nonlinear dynamic time history analysis of the base isolated structure is carried out,and the seismic behavior of the structure is studied.According to the constitutive relation of concrete and steel material,the performance criterion of the components is defined,the elasticity-plasticity analysis model of the isolated structure is established,and the damage characteristics of the base isolated structure in the long period ground motion are discussed,them the measures to improve the long period seismic performance of the isolated structure with steel support are put forward.The results show that under the same ground motion intensity,compared with the common ground motion,the damage of the structure under the long period ground motion is the most serious,which is a relatively weak part of the structure,and the long period seismic performance of the isolated structure can be effectively improved by setting the steel support in the bottom of the structure.%为研究长周期地震动下基础隔震结构的抗震性能,根据目前长周期地震动的界定方法,共选取18条近场和远场长周期地震动记录作为外部输入,对基础隔震结构进行非线性动力时程分析.根据混凝土和钢筋材料的本构关系,定义了构件的性能准则,建立了隔震结构的弹塑性分析模型,探讨了基础隔震结构在长周期地震动作用各构件破坏的变化特点,并提出利用钢支撑改善隔震结构长周期抗震性能的加固措施.研究结果表明,在相同地震动强度下,相对于普通地震动,结构在长周期地震动作用下底层的破坏最为严重,是结构的相对薄弱部位,通过在结构底层外侧柱间设置钢支撑,能够有效提高隔震结构的长周期抗震性能.