近场地震作用下不规则层间隔震结构的动力响应分析

Dynamic Response Analysis of Irregular Story Isolation Structures under Near-field Earthquake Conditions

层间隔震结构作为一种新型的隔震形式,不仅可以降低上部结构的动力响应,还可以弥补基础隔震结构的不足。现有研究多集中在远场地震作用下的规则层间隔震结构。本文利用通用结构分析与设计软件SAP2000分别模拟了一幢8层带裙房钢筋混凝土框架层间隔震结构、基础隔震结构和抗震结构,分析并对比了三种结构在近场地震作用下动力响应特征。结果表明在近场条件下三种结构顶层均出现不同程度的鞭梢效应;相比抗震结构两种隔震结构具有很好的减震效果,而且基础隔震结构的减震效果好于层间隔震结构;由于结构刚度突变的部位剪力较大,所以应对其裙楼顶部予以加强。

As a new form of isolation,the story isolation structure not only can reduce the dynamic response of upper structures but also can make up for the deficiency of foundation isolation structures.The existing literature mostly analyzes the regulated story isolation structures in far-field earthquakes.In this paper,an eight-story house with a podium-reinforced concrete frame story isolation structure,a foundation isolation structure,and a seismic structure are simulated by using SAP2000.The dynamic responses of the three structures in near-field earthquake conditions are compared.The results show that the whiplash effect is different in the top stories of the three structures in the near-field conditions.However,compared with the seismic structure,the other two kinds of isolated structures show very good damping behavior.In addition,the damping properties of the foundation isolation structure are better than the story isolation structure.Therefore,structures with a podium should be strengthened at the top of the podium.