结构动力抗震可靠度理论的研究进展

State-of-the-Art of Dynamic Seismic Reliability Theories of Structures

从状态变量模型、基本变量模型和实用简化模型3个方面,对结构动力抗震可靠度理论的研究进展系统地进行了总结与评述.针对状态变量模型,结合随机振动理论,将随机振动分析方法分为两类:第1类是面向数字特征的方法,主要解决结构的随机反应从基本随机变量空间到状态变量空间的统计矩演化问题;第2类是面向概率密度的方法,主要解决结构的随机反应从基本随机变量空间到状态变量空间的概率密度演化问题.分别评述了两类方法中的代表性方法:等价线性化方法和概率密度演化方法.针对基本变量模型,分别总结了考虑系统参数随机性的结构动力抗震可靠度分析方法,以及将动力可靠度问题转化为静力可靠度问题的理论和方法,对近年来提出的尾部等效线性化方法、子集模拟法、等价极值法等进行了对比分析.针对实用简化模型,总结评述了3种方法:基于随机地震动模拟-确定性时程分析的直接方法、基于一致危险性反应谱和等效非线性体系的简化方法、基于可靠度简化解析表达式与数值模拟的半解析方法.最后,对新近提出的结构整体抗震可靠度理论及其存在的问题进行了归纳分析,并从地震作用的输入模型、主要失效模式的搜索、结构的破坏准则、结构失效模式的多重性、结构的整体极限状态方程等方面给出了研究建议.

The state-of-the-art of theories on dynamic seismic reliability of structures is systematically reviewed from three aspects： state variable models,basic variable models,and pragmatic simplified models. For the state variable models,using the random vibration theory,methodologies for random vibration analysis are classified into two categories： One is the statistical-characteristics oriented methods,which deal with the problems of evolution of statistical moments from the space of basic random variables into the space of the state variable; another is the probability-density oriented methods,which cope with the problems of evolution of probability density from the space of basic random variables into the space of the state variable. Two representative methods of the two categories,namely the statistical linearization approach and the probability density evolution method,are critically discussed. For the basic variable models,the methods for analysis of dynamic seismic reliability of structures that take into consideration the randomness in system parameters,and the theory andmethods of transformation from the dynamic reliability problems into static ones,are summarized;then,a comparison analysis is made for the recently proposed methods,including the tail equivalence linearization method,the subset simulation,and the equivalent extreme events method. For the pragmatic simplified models,three methodologies are reviewed,including the direct approach based on stochastic ground motion simulation and deterministic time-history analysis,the simplified approach based on the uniform-hazard response spectrum and equivalent nonlinear systems,and the semianalytical approach based on simplified analytical formulations of seismic reliability and numerical simulation. Finally,the problems existing in the recent global seismic reliability theories of structures are discussed and summarized. In addition,some suggestions are provided for input models of seismic actions,search of the main failure modes,failure criteria of structures,multiple properties of structural failure modes,and global limit state functions of structures.