地表多层框架结构地震反应分析

Seismic Response Characteristics Analysis of Above-ground Multi-layer Frame Structure

考虑土体-结构动力相互作用,通过有限元软件建立了一个含有三层地下室的框架结构,对其进行地震作用下的三维动力反应分析。对比研究了地震动频谱,地震动峰值加速度,结构动力特性和土体动力特性对其地震响应的影响。结果表明:结构地震反应虽然在不同工况下不尽相同,但整体符合一定规律,地下室顶底板处中柱的受力较大,呈现出剪切变形的模式;场地土体的动力特性和地震动峰值对结构地下部分地震反应影响显著;结构频率和地震动频谱特性对结构中柱地下部分地震反应影响较小,采用Fourier谱强度平均频率匹配度可较好的反映地震动频谱特性和结构自振频率的共振效应引起的地震反应放大。

A three-story basement frame structure is established by finite element software.Considering the dynamic interaction of soil structure,a three-dimensional dynamic response analysis is performed under earthquake action.The effects of ground motion spectrum,peak acceleration of ground motion,structural dynamic characteristics and soil dynamic characteristics on its seismic response were analyzed quantitatively.The results show that although the seismic responses of the upper and lower parts of the structure are different under different working conditions,they conform to a certain law as a whole.The middle column at the top and bottom of the basement has a large force and presents a shear deformation pattern.The dynamic characteristics of the soil on the site and the peak value of ground motion have a significant effects on the seismic response of the underground part of the structure;the structural frequency and the frequency spectrum characteristics of the ground motion have a small effects on the seismic response of the underground part of the column in the structure.The seismic response amplified by the resonance effect of the frequency spectrum characteristics of the ground motion and the structure’s natural frequency.