地震作用下混凝土高趾墙损伤分析

采用混凝土塑性损伤模型和堆石料广义塑性模型,对带有高趾墙的混凝土面板堆石坝静动力反应特性进行了二维有限元分析,研究了高趾墙的损伤发生及发展过程。结果表明,高趾墙在施工和蓄水过程中上、下游两侧受到拉、压应力交替作用,竣工期最大拉应力发生在高趾墙下游面底部,满蓄期最大拉应力发生在高趾墙上游面底部,由于拉应力超过了混凝土抗拉强度,高趾墙出现了轻微损伤;在地震荷载作用下,高趾墙底部损伤程度增大,损伤因子最大超过0.8,同时高趾墙顶部也有轻微损伤,损伤因子小于0.6。通过损伤变量可以清晰地看出高趾墙在地震作用下的破坏过程及薄弱环节,可为混凝土面板堆石坝抗震设计提供理论指导。

Damage Analysis of High Toe Wall Subjected to Earthquake

The plastic-damage model of concrete and the elastic-plastic model of rock are applied to analyze the static and dynamic force characteristics of CFRD with high toe wall. And then the damage occurrence and development process of high toe wall is studied. The results show that the upstream and downstream of high toe wall withstand tensile stress and compressive stress during the construction and storage process; the maximum tensile stress occurs in the bottom of the high toe wall; the damage appears because the tensile stress exceeds the strength of concrete; the damage of high toe wall at the bottom increases owing to earthquake, and the maximum of index is greater than 0.8; at the top of high toe wall, the maximum of index is lesser than 0.6. The damage index could be used for the analysis of the high toe wall damage development process, which can provide theoretical support for aseismic design of the CFRD.