层间隔震结构随机响应与动力可靠度研究

Random response and dynamic reliability of story isolation structure

针对层间隔震结构体系,考虑结构阻尼矩阵的非比例特性,建立小震下非比例阻尼层间隔震结构动力分析模型,采用零均值的Clough-Penzien双过滤功率谱模型,运用虚拟激励法对层间隔震结构进行随机响应分析,得到了结构各层的层间位移响应峰值统计量,建立极限状态下的功能状态方程,利用当量正态化法,通过串联模式,研究层间隔震结构的动力可靠度.最后以一栋12层的框架剪力墙结构为算例,根据建立的方法比较层间隔震结构与非隔震结构的层间位移响应和总体体系失效概率,分析隔震层刚度、隔震层阻尼以及场地类别在小震作用下对层间隔震结构体系失效概率的影响.结果表明,层间隔震结构的整体失效概率比非隔震结构明显降低,且随着隔震层刚度的增大而上升,随着隔震层阻尼的增加而下降,结构场地土越坚硬,可靠性越高.

Aimed at story isolation system, a non-proportionally damped story isolation structure is established, Clough-Penzien seismic random model is used to analyze random response of story isolation structure by PEM method, the performance equation is established to calculate dynamic reliability of structure by JC method, and the total reliability of structure is derived by regarding the stories to be of series relation. A 12-story frame shear- wal l structure is taken as a example, story drift response and fai lure probabi l ity of story isolation structure is compared to non-isolated structure, the effect of isolation stiffness, isolation damping and soil profi le on the sys-tem reliability is analyzed. Results show that the dynamic reliability of the story isolation structure is greatly im-proved compared with that of the non isolated structure, the fai lure probabi l ity of story isolation structure increa-ses with the increase of isolation layer stiffness and decreases with the increase of isolation layer damping ratio. The harder the soil it in site, the higher the system reliability is obtained.