强震下钢筋混凝土框架结构残余位移研究

Study of residual displacement of reinforced concrete frame structures under strong earthquake

针对钢筋混凝土框架结构,提出了残余位移的近似计算方法,选取了合适的层间残余位移指标,通过非线性时程分析,研究了强震下结构层间残余位移的分布规律和影响因素,建立了层间残余位移的简化计算公式.结果表明:当采用自由振动法计算强震下钢筋混凝土框架结构的残余位移时,地震波持时延长宜大于等于结构基本周期的10倍;随着材料强度等级的增加,结构层间残余位移系数在总体上降低;随着楼层屈服强度系数变大,结构层间残余位移系数减小,且二者之间近似存在指数函数关系.

An approximate method for calculating residual displacement is proposed for reinforced concrete （RC） frame structures. After selecting appropriate storey residual displacement indicator, the distribution characteristics and influence factors of the storey residual displacement of the RC frame structure under strong earthquake are studied by way of nonlinear time history analysis. Finally, a simplified formula for estimating the storey residual displacement of the RC frame structure is established. The results indicate that the duration of seismic wave should be extended no less than ten times the basic period of structure when the free vibration method is adopted to calculate the residual displacement of the RC frame structure under strong earthquake. The storey residual displacement ratio decreases with the increase of material strength grade. In addition, the storey residual displacement ratio drops with the increase of the storey yield strength coefficient and there is exponential function relationship existing approximately between them.