近场地震作用下隔震结构分析方法探讨

Analysis methods discussion of isolated structures on near-filed ground motions

近场地震具有不同于远场地震的动力特性。我国规范中引入了近场系数的概念来考虑近场地震对隔震结构的影响,但未对设计过程中的具体操作做出明确规定。提出了三种考虑近场影响的设计方法,并选取了一栋5层钢筋混凝土框架结构计算实例加以说明。对比结果表明,考虑近场影响对隔震支座变形提出了更高的要求,虽有所降低但仍具有很好的减震效果。本文提出的方法操作简单,有利于设计人员在工程中的应用。

There are different dynamic characteristics between near-filed and far-field ground motions.The concept of near-filed coefficient was introduced in the code for seismic design of buildings.But its concrete operation was not given.Three kinds of design methods with near-field influence were presented.Taking a 5-story reinforced concrete frame structure as an example,the analysis results were illustrated.The result shows that near-filed coefficient puts forward higher requirements for bearing deformation,and the shock absorption effect is still all right.The method proposed is simple and easy to operate,which is conducive to designer in the application.