ABSTRACT

Seismic performance of postmainshock buildings considering seismic mainshock-aftershock sequences are studied. The case studies correspond to three SAC steel MRF buildings of three, nine and twenty stories. The 2-D models are able to capture important properties of deterioration of strength and stiffness. Endurance time method is used to predict the response of structures in different hazard levels. Results are compared with those from of nonlinear incremental dynamic analysis. Maximum dynamic seismic responses of structures are captured during synthetic mainshock-aftershock seismic sequences which are produced by endurance time method. Interactional-conceptual curves for different seismic performance levels and residual collapse capacity of post-mainshock damaged buildings are presented. The collapse fragility curves of case studies are extracted. The results show that the residual seismic response of building caused by the mainshock and the direction of applied aftershocks are highly significant factors in evaluation of postmainshock buildings. It is found that in a seismic sequence which has two earthquakes with different intensities, occurrence of the stronger shake before the less intensive one, imposes higher seismic risk to the building.

摘要

研究了考虑地震主震-余震序列的后主震建筑物的抗震性能。案例研究对应于三层、九层和二十层的三座 SAC 钢 MRF 建筑物。二维模型能够捕捉强度和刚度恶化的重要特性。耐久性时间法用于预测结构在不同危险等级下的响应。结果与非线性增量动态分析的结果进行了比较。结构的最大动态地震响应是在通过耐力时间法产生的合成主震-余震地震序列中捕获的。给出了不同抗震性能水平和主震后受损建筑物的剩余倒塌能力的相互作用-概念曲线。提取案例研究的坍塌脆性曲线。结果表明，主震引起的建筑物残余地震响应和余震作用方向是评价主震后建筑物的重要因素。研究发现，在具有两次不同强度地震的地震序列中，在强度较小的地震之前发生较强的震动，给建筑物带来更高的地震风险。