【摘要】 在基于性能抗震设计中,要求实现多级设防,目的是使结构抗震设计不仅要保护生命安全,同时也要控制因结构破坏而带来的经济损失,使结构在整个生命周期内费用达到最小。但由于结构抗震设计中存在着大量的不确定因素,使得实现每个性能水平都是不确定的,因此,每个性能水平的目标可靠度究竟取多高才能达到设计要求,是目前抗震设计的一个基本问题。针对这一问题,将地震作用、自重荷载、材料强度等看作随机变量,分析了结构造价与失效概率之间的近似关系,明确了不同性能水平失效概率之间的合理比例关系,采用"投资-效益"准则,且控制人员伤亡率小于社会可接受水平,来确定结构的目标性能水平。以两个钢筋混凝土框架结构为例,说明了该方法的应用。更多还原

【Abstract】 Implementation of multi-level fortification is a basic requirment of performance-based seismic design.It aims to not only protect people’s life but also control economic losses caused by damaged buildings.Three are many random factors in seismic design procedure,which lead to that the implementation of seismic performance of buildings has uncertainty.So how to determine target performance level is a basic problem for performance-based seismic design.In this paper,a new method is presented for determining the target performance level and the target performance level is determined by "cost-benefit" criteria,based on establishing the relation between the structural cost and failure probability and defining the relations among failure probabilities of different performances levels.更多还原