针对基础隔震的高层建筑,基于首次超越理论,计算了各个隔震支座在非平稳随机激励下发生基础提离破坏的易损性曲线。隔震结构采用三维有限元建模,隔震支座采用Bouc—Wen模型,经过等效线性化后,应用虚拟激励法求得结构的随机响应。讨论了隔震支座的阻尼比、屈服力以及地震动输入方向对隔震支座易损性曲线的影响。研究发现:增加隔震支座的阻尼比或是增加隔震支座的屈服力都会使得隔震支座发生基础提离的破坏概率增加,地震动的输入方向对隔震支座基础提离易损性曲线影响十分显著。
Uplift fragility curves of all the isolators for a base-isolated high-rise building subjected to nonstationary random excitations are obtained based on the first excursion failure. The isolated structure is modeled by the finite element method,and the isolators are described by the Bout-Wen model. The stochastic responses are obtained by the pseudo excitation method after the linearization of the isolators. The influences of the damping ratio,yield force of the isolators and the direction of the ground motion on the uplift fragility curves are investigated,respectively. The results show that the probability of failure by uplift increases with the increase of either damping ratio or yield force of the isolators; the direction of the input excitations affects the uplift fragility curves significantly.