小高宽比隔震结构双向输入振动台试验研究及数值分析

本文对高宽比为2.5的普通钢框架隔震结构模型,采用多种不同的地震动进行了水平向和竖向双向地震输入的振动台试验研究,并利用时程分析法完成了模型结构地震反应的数值分析。试验结果表明,高宽比隔震结构在水平向和竖向双向输入情况下隔震层基本上不会进入拉伸应力状态,即使在9度大震E l Centro和Hach inohe波输入时,隔震层支座仍以受压为主。因此小高宽比隔震结构在场地好的情况下,结构不会出现倾覆,仅需考虑软弱土场地的受拉情况。试验发现竖向地震输入对小高宽比隔震结构水平反应的影响相当小;对小高宽比隔震结构进行水平向地震反应分析时,可以忽略竖向地震对结构的影响。

Shaking table test and numerical analysis for an isolated structure with small aspect ratio under earthquake inputs in two directions

The shaking table test under horizontal and vertical earthquake inputs with different wave forms are completed for a steel frame model with aspect ratio 2.5,and the earthquake response numercial analysis for the model structure are also performed by time history analysis method.The experiment results show that the isolated structure with small aspect ratio will not enter the tension stress state under the earthquake action in two directions.The isolation layer is still in compression state even under the action of strong earthquake of El Centro and Taft waves with PGA 0.6g.Therefore,the isolated structures with small aspect ratio will not be ovverturned when the soil is hard.However,it should be considered when the isolated strucutres are built on the soft soil.The test results show that the vertical earthquake input has little influence on the response of isolated structure in horizontal direction.It is proposed that the influence on structural response to vertical earthquake input may be ignored when we analyze the earthquake response in horizontal direction for the isolated structure with small aspect ratio.