大高宽比隔震结构模型水平向振动台试验

Experimental Study on Horizontal Vibration Table of Isolated Structure Model with Large Height-width Ratio

目的为隔震设计理论和规范的编制提供试验依据.方法对1∶4(缩尺)比例的大高宽比铅芯橡胶垫隔震结构模型进行高烈度区不同场地波下水平向振动台试验研究,观测隔震结构的动力响应.结果高烈度区的某些地震波激励下,大高宽隔震结构中的支座出现了拉力或者非线性变形.结论当输入地震波中长周期分量较多时,隔震结构隔震后的效果不是很好,隔震支座滞回曲线是均匀饱满的;当输入高烈度地震波时,对于像试验所选择的大高宽比结构,上部结构弯曲变形已开始占了较大部分;在高烈度地区应用橡胶隔震结构,橡胶垫要承受一定的拉应力,但是结构整体是安全的,而在某些不利地震动下,橡胶垫可能要受拉屈曲,因而此时结构是处于倾覆的临界状态.

Isolation technology was applied to High-Rise buildings. It has markedly reduced structure cost and improved earthquake-resistant performance. But rubber bearing has characteristic of weak tension, so bearing of isolation structure with large height-width ratio is likely to have tension or no-linear deformation under some earthquakes wave put in high intensity size, and turnover risk exists in structure. There are few researches on the damage now. The paper presents the result of an experimental study on horizontal shaking table of large ratio of height to width isolated structure model with lead-plug rubber bearing on a scale down of 1-4 under high intensity earthquake wave input. And dynamic responses of the isolation structure were observed. Test data show that rubber bearing should bear certain draw stress in high earthquake intensity area, but the whole structure is safe; while in some unfavorable earthquake waves, rubber bearing might be drawn into bucking, and therefore the structure is in the critical overturn state at this moment. Analyses of correlative data can provide experimental basis for design theory and standard program of the isolation structure.