橡胶垫隔震支座结构高宽比限值研究

Study on limit of height to width ratio for base isolated buildings with rubber bearings under earthquake

本文对叠层橡胶垫隔震结构的高宽比限值进行了研究,导出了实用的简化计算公式,分析了地震动峰值、场地条件、隔震层刚度、上部结构刚度(反映了上部结构类型)、橡胶垫的布置等因素对隔震结构高宽比限值的影响及其变化规律。给出了不同条件下具有统计意义的隔震结构高宽比限值的定量范围,并提供了提高隔震结构高宽比的有效方法,得出了一些具有实际意义的结论,为工程计算与设计提供了方法和依据。本文结果可供编制有关规范和规程参考。

The limit of height to width ratio for base isolated building with the elastomeric rubber bearings is of considerable concern to structural design engineers. Nevertheless, until now, no systematical and quantitative study has been done on this problem for the base isolated buildings. For this reason, the main objective of this paper is to focus on investigations on the limit of the for isolated building with the rubber bearings under different conditions subjected to earthquake excitations. The simplified formulation has been derived and some influenced factors, such as the site soil conditions, seismic peak acceleration, period of the isolated system, period of the superstructure and layout of isolators, have been studied and discussed. According to the numerical results, it has been found that the effects of site soil conditions on the limit values are significant, in which the softer the site, the smaller is the limit value under different seismic intensities, the predominant period of isolated building also plays an important role in the limit value, namely, the isolated building with a longer period may have a relatively large value, while the stiffness of superstructure has little effect on the limit value. Furthermore, an effective method to improve the limit value has been proposed in the paper.