主震余震序列作用下混凝土坝地震易损性研究

This project aims to the limitation that current assessment of the aseismic performance of concrete dams without considering the impact of aftershocks. Shaking table model test and nonlinear time history analysis are combined to study the fragility of damaged concrete dams under aftershocks by using analytical methods based on seismic vulnerability assessment. Based on the parameters’ statistical characteristic of the mainshocks and aftershocks , the model to synthesis the mainshock-aftershock acceleration sequences will be established; accordding to the damage evolution model of concrete dams under strong earthquake, the qualitative damage measure indicators of concrete dams will be established, and the damage grading criterions for concrete dams will be investigated; Comparing the damage fragility curves of concrete dam under the mainshocks and mainshock-aftershocks, the effects of aftershocks on seismic vulnerability of the damaged concrete dams will be explored, the seismic safety of damaged concrete dams will be evaluated. The outcomes of this research are expected to reveal the mechanism of catastrophic damage of damaged concrete dam under the aftershocks, state the impact of aftershocks onr seismic safety of concrete dams, provide a reference for seismic design and aseismic provision revision of concrete dams.

本项目针对目前混凝土坝抗震性能评估不考虑余震影响的局限性，拟采用动力模型试验和非线性时程数值模拟相结合的手段，基于抗震评估的易损性分析方法，对主震余震序列作用下混凝土坝的灾变机理开展以下系统的研究：基于主震余震地震特征参数的统计规律，建立主震余震加速度序列合成模型；根据混凝土坝在强震作用下的损伤演化模式，建立混凝土坝损伤破坏描述的定性指标，探讨混凝土坝在地震作用下的损伤分级标准；对比主震作用下混凝土坝的易损性曲线和余震作用下受损混凝土坝的易损性曲线，探索余震对受损混凝土坝地震易损性的影响规律，评价受损混凝土坝在余震作用下的地震安全性。项目研究成果有望揭示主震余震序列作用下混凝土坝的灾变机理，阐明余震对于混凝土坝抗震安全性的影响，为混凝土坝的抗震设计及规范修订提供参考。