摘要
结构失效模式决定了结构在强震下的抗震性能。该文采用基于可靠度理论的割集方法,对掉层框架结构地震作用下的典型失效模型的失效概率进行评估,并与规则框架结构进行对比,分析了掉层框架结构失效模式的特点。结果表明:掉层框架结构的柱极限剪切失效模式年平均发生概率高于规则结构,且掉层框架结构存在剪切破坏先于弯曲破坏的风险,应采取适当加强措施以满足"强剪弱弯"的设计原则;对掉层结构进行基于年平均概率的柱剪力增大系数分析,建议对掉层结构上接地柱进行抗剪承载力设计时,采用抗震等级提高一级所对应的剪力增大系数,且上接地柱全柱段箍筋应加密布置。
Structural failure modes play an important role in the seismic performance of RC buildings under strong earthquakes. Typical failure mode-based failure probability of the RC frame supported by foundations with different elevations is evaluated by cut-set method based on system reliability theory, and compared with that of regular frame counterparts. The results show that the annual average failure probability of ultimate shear mode of the frame supported by stepped foundation is higher than that of regular frames, and the risk of shear failure before bending failure exists. Appropriate strengthening measures should be conducted to satisfy the design principle of strong shear-weak bending. By comparing the designs with different shear-amplification coefficients, it is suggested that the seismic level which determines the shear-amplification coefficient be one level higher for the design of shear bearing capacity of the upper embedding column, and dense hoop reinforcement be arranged over the whole length of the upper embedding column.
作者
刘流
李英民
姬淑艳
LIU Liu;LI Ying-min;JI Shu-yan(School of civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China;School of Construction Management and Real Estate,Chongqing University,Chongqing 400045,China)
出处
《工程力学》
EI
CSCD
北大核心
2020年第5期74-81,共8页
Engineering Mechanics
基金
国家自然科学基金重点项目(51638002)
国家自然科学基金项目(51878101)。
关键词
RC掉层框架结构
失效模式
割集方法
易损性分析
强剪弱弯
RC frame supported by foundations with different elevations
failure mode
cut-set method
fragility analysis
strong shear-weak bending
