近场地震动作用下复合自复位结构考虑残余位移的性能评估

摘要

As a structural solution to achieve earthquake resilience,an innovative self-centering dual system is proposed,and performance assessment is conducted based on joint probabilistic density function.This dual system is divided into two subsystems:an occupancy subsystem and a damage controlling subsystem.The occupancy subsystem provides normal occupancy function and sustains major seismic response;the damage controlling subsystem provides self-centering and energy dissipation mechanisms,bears the rest of seismic response,and controls the degree of drift concentration along the height of the structure.In order to exemplify the proposed system,a sample structure is designed according to a stiffness demand method and assessed with a probabilistic framework.This framework is based on joint probabilistic density function and takes maximum interstory drift and residual interstory drift as two random variables.Fragility curves,joint fragility matrix,as well as joint drift demand surfaces are derived.It is found that the system can effectively reduce fragility probability and the degree of drift concentration.Moreover,it is concluded that the damage controlling subsystem could reduce the maximum interstory drift and residual interstory drift of the occupancy subsystem,and keep the occupancy subsystem from weak-story failure mode.%作为实现震后可恢复的一种结构解决方案,提出了一种复合自复位结构,并基于联合概率密度函数对其进行性能评估.复合自复位结构将结构在体系层次上分为基本功能分区和损伤控制分区.基本功能分区实现结构的正常使用功能,承担大部分的地震作用和全部的重力荷载;损伤分区实现结构自复位和耗能,分担剩余的地震作用和控制结构的层间位移集中程度.基于刚度需求的设计该结构,并对其基于联合概率密度函数进行评估,将最大层间位移角和残余层间位移角作为变量,计算得到易损性曲线、联合易损性概率矩阵和联合需求位移角曲面.结果表明,该体系不仅可以有效降低结构的损伤概率,而且可以有效地控制结构的层间位移集中程度.耗能分区可以通过耗能和自复位降低基本功能分区的最大层间位移角和残余层间位移角,并且可以降低结构出现局部薄弱层的整体损伤模式.