提出了双向近场和远场地震作用下,隔震结构概率工程需求分析的基本步骤和具体计算方法,以某实际隔震结构为例,给出了工程需求参数的选择、结构性能水准及抗震设防目标的具体确定。以地震波的PGA为IM,利用基于增量动力分析方法的条带调整法,计算了该隔震结构IO、LS、CP各性能极限状态的易损性曲线,绘制了近场和远场地震作用下50年设计基准期内上部结构最大层间位移角和隔震支座最大位移的超越概率曲线。根据此曲线,对隔震结构的抗震性能进行了概率评估。
The step and method are presented to analyze probabilistic seismic demand of bas e isolation structures.Rearding an eight-story RC frame isolation building as example,the procedures to choose the engineering demand parameter,structural p erformance level and seismic performance objectives are discussed.Using the PGA of the earthquake records as the IM,the seismic fragility curves of IO,LS,CP limited performance level for the isolation buildings are calculated based on t he strip IDA analysis method,and the exceedance probability curves in 50 years of peak story drift ration of the superstructure and peak displacement of the is olator are plotted.According to these curves,the probabilistic seismic perform ance of this isolation building can be assessed.