结构-地基耦合振动下地震反应谱特性

随着结构震害统计资料的不断增加,许多结构在地震作用下的宏观破坏现象用现有的反应谱理论不能获得合理的解释。在地震中,结构-地基耦合振动十分明显。就此问题出发,利用集总参数法建立了结构-地基耦合振动模型,分析推导了该模型下的地震反应谱公式。通过实例计算得出了耦合体系在不同频率地震波作用下的反应谱曲线,得出了一些有意义的结论。研究结果表明,对于具有浅埋刚性基础的结构体系在考虑耦合后的地震响应值与现有反应谱理论计算值有明显差异,地震作用在较大结构周期跨度上得到折减,同时,耦合体系对特定频率的地震波有吸收作用,现有反应谱理论没有体现这一点有利作用。

THE CHARACTERISTIC OF THE RESPONDS SPECTRUM OF THE EARTHQUAKE ON THE STRUCTURE-GROUNDSILL COUPLED OSCILLATION

With the unceasing increase of the statistical data in structure disaster of earthquake,many macro-phenomenon of structure damages in earthquake cannot be explained reasonably by the existing response spectrum theory.In earthquakes,it is very obvious for the structure-groundsill coupled oscillation.On this question,we established the structure-groundsill coupled oscillation model using the lumped parameter method.And we analyzed and inferred the formula of earthquake respond spectrum using this model.By calculating the case,we obtained the curve of response spectrum of coupling system in the action of the different frequency seismic wave,and obtained some significance conclusion.The result of research showed that it is obviously different between the earthquake respond value and the calculational value of the existing respond spectrum theory for the shallow buried rigid foundation structure system considering coupling.The earthquake function has some discount in the bigger structure cycle span.At the same time,the coupling system has the absorption action to the certain frequency seismic wave.The existing response spectrum theory doesn't show the advantageous function.