剪切型结构的抗震强度折减系数研究  

Analysis of seismic strength reduction factors for shear-type structures

作　　者：周靖[1] 蔡健[2] 方小丹[2] 

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105 [2]华南理工大学建筑学院,广东广州510640

出　　处：《地震工程与工程振动》2008年第2期64-71,共8页Earthquake Engineering and Engineering Dynamics

基　　金：湖南省科技计划项目(2007CK3066)

摘　　要：为了研究剪切型结构抗震强度需求的变化规律,本文基于单自由度体系的非线性时程分析,研究了不同场地条件下延性折减系数与位移延性系数和结构自振周期的关系;采用修正等效单自由度体系位移延性折减系数的方法,研究了剪切型多自由度体系的延性折减系数;以基于中国建筑抗震规范设计的代表不同抗震能力要求的RC框架结构为分析对象,通过静力弹塑性分析,研究了RC框架结构的体系超强能力。分析结果表明场地类别、位移延性水准和结构振动周期对单自由度体系的延性折减系数有显著的影响;多自由度体系的抗震延性折减系数明显比其相应的等效单自由度体系的抗震延性折减系数小;RC框架结构的超强系数一般随结构楼层数的增加而减小,随抗震设防烈度的增大而减小,内框架的超强系数比边框架的超强系数大。In order to analyze the characteristic of the seismic strength demand for shear-type structures, this paper analyzes the relationship between ductility reduction factors and displacement ductility factors with structure natural vibration period by the nonlinear time-history analysis of single-degree-of-freedom systems subjected to earthquake ground motions in different site conditions. Ductility reduction factors of multi-degree-of-freedom shear-type systems are investigated through modifying the ductility reduction factors of equivalent single-degree-of-freedom systems. Based on the reinforced concrete frames structures with various seismic capacities, the seismic overstrength capacity of these frames designed according to China code for seismic design of buildings, by means of inelastic static pushover analysis, is assessed. Analysis results indicate that the site conditions, displacement ductility and natural vibration period have an important influence on the ductility reduction factors of single-degree-of-freedom. The ductility reduction factors of multi-degree-of-freedom systems are clearly smaller than that of equivalent single-degree-of- freedom systems. The structural overstrength factors decrease with increaing number of storey and seismic fortification intensity. The structural overstrength factors of the inner frame are greater than that of exterior frame.

关 键 词：剪切型结构 抗震 强度折减系数 延性折减系数 超强系数 

分 类 号：P315.951[天文地球—地震学]