高层基础隔震建筑非平稳随机响应改进算法

利用虚拟激励法和等效线性化技术，计算了基础隔震高层建筑的非平稳随机响应。研究了高阶振型对高层隔震建筑响应的影响，提出了针对基础隔震结构随机响应分析的改进算法。计算中假定隔震建筑上部结构在大震作用下依然保持弹性状态，塑性变形集中在隔震层处，隔震层的恢复力-位移本构关系采用Bouc-Wen模型来描述。上部结构只需要提取前若干阶振型参与动力计算，剩余的高阶振型对结构响应的贡献按照静力校正技术求得。研究表明，改进的计算方法在没有显著增加计算量的同时，通过近似考虑高阶振型的影响，有效地提高了计算的精度。

An improved method for non-stationary stochastic seismic response analysis of base-isolated high-rise buildings

The seismic analysis of base-isolated high-rise buildings subjected to non-stationary excitation is performed by the pseudo excitation method and the equivalent linearization technique. The influence of the high order modes of the superstructure on the responses of the base-isolated high-rise building is investigated, and an improved method for stochastic seismic analysis of such buildings is presented. The superstructure of the isolated system is assumed to remain elastic under major earthquakes, and the plastic deformation concentrates in the isolation layer. The relationship between restoring force and displacement of isolators is described by the Bouc-wen model. The lower modes are taken into account in the dynamic response analysis, while the contribution of the remaining higher modes to the structural responses is approximated by using the static correction procedure. It is shown that the new method improves the accuracy of the responses by taking into account the contribution of higher modes, while only increases the computational effort slightly.