并联基础隔震结构的地震随机响应分析

Analysis of random responses to earthquake of parallel base isolated structure

运用随机振动理论,分析了地震作用下并联基础隔震结构层间最大位移的概率统计特性,导出了其均值和均方差的计算公式。选用一个采用并联基础隔震的4层钢筋混凝土框架作为数值算例,通过地震随机响应分析,得出了隔震结构各层层间最大位移的均值及均方差响应,通过增大上部结构自振频率与隔震结构自振频率的比值以及增大隔震层的摩擦屈服剪力都可以降低隔震层最大位移的均值响应。

In accordance with the random vibration theory, the statistical probabilistic characteristics about the maximum displacement response between layers of parallel base isolated structure, are analyzed; the calculating formula of displacement mean value and standard variation value are derived. With a 4-story parallel base isolated RC frame chosen as numerical example, the results of the mean and standard variation responses of the maximum inter-story drift are gained. It indicates that the maximum displacement mean value of the isolation layer will reduce if the fundamental frequency ratio of base isolation system to the fixed base system and the yielding force of the isolation layer are increased.