残余位移是基于性能抗震设计方法中一个重要的性能参数,其研究逐步得到重视,但是目前还没有简单有效的工程计算方法。该文通过计算不同参数的双折线单自由度(SDOF)体系在120条地震动作用下的残余位移响应,提出残余位移角的概念,分析屈服后刚度比、强度折减系数、周期、场地条件等参数对残余位移角的影响。分析结果表明,屈服后刚度比、周期、场地条件是影响结构震后残余位移率的主要参数,其中以屈服后刚度比的影响最为明显,而强度折减系数对残余位移率的影响不明显。文中还分析了地震动峰值参数(PGA、PGV、PGD)与残余位移率之间的相关性,结果显示地震动峰值参数与残余位移率的相关性随周期的不同而不同,其中以PGV参数与残余位移之间的相关性最好。基于这些研究,给出等强度残余位移谱,并且提出形式简单的拟合公式。
Residual deformation is a vital parameter for Performance-Based Seismic Design (PBSD), which attracts research attentions all around the world. However, there is no efficient way to calculate the residual deformation of structure after it experiences a major earthquake. This study calculated the residual deformation of SDOF ( singledegree of freedom) system with various parameters under 120 different earthquake inputs. The concept of residual deformation ratio was proposed. The influences of post-yield stiffness ratio, strength reduction ratio, structure period and site condition on the residual deformation ratio were evaluated. The analysis results show that the post-yield stiffness ratio, structure period and site condition are three major parameters, among which the post-yield stiffness ratio is the most important parameter that controls the residual deformation. The influence of strength reduction ratio can be neglected. This work also analyzed the correlation between residual deformation and three ground motion intensity indices, namely, Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV) and Peak Ground Displacement (PGD). The results show that the Spearman correlation coefficient between PGA/PGV/PGD and residual deformation ratio differs with, the structure period, and PGV has the best linear correlation among these three indices. Based on these studies, a constant- relative-strength residual deformation ratio spectrum was proposed and a fitting formula in simple form was presented for seismic design.