在考虑混凝土材料细观非均匀性影响的基础上，探讨了在材料参数和地震动等不确定性因素影响下混凝土重力坝的破坏过程和破坏形态。通过对金安桥混凝土重力坝的180个样本的非线性数值模拟统计分析，得到了不同水平地震作用下的大坝损伤破坏情况，并提炼出4种典型的破坏形态。计算结果表明随着地震动的增大，大坝损伤总体上趋于严重，但也存在高地震动水平下轻微损伤的情况。典型的破坏形态除了坝头折断、坝踵开裂以外，还发现了下游面起裂、贯穿至上游的情况，且随着地震峰值加速度的增大而越发明显。这对于全面了解重力坝地震损伤的薄弱环节，优化抗震措施提高大坝抗震能力是十分有意义的。%The damage process and failure modes of concrete gravity dams affected by uncertain material properties and ground motion input are studied by numerical simulation. Based on 180 samples of nonlinear time-history analysis of the Jin＇anqiao RCC Gravity Dam with the influences of concrete heterogeneity taken into account, the damage states of the dam subjected to different levels of ground motion are obtained, from which four typical failure modes are generalized. The simulation results show that stronger ground mo- tion leads to more severe damage. But uncertainty exists, which means that the dam may stand in a strong earthquake but fail in a moderate one. Due to the uncertainty of material properties. Concerning the failure modes, besides the damage at the dam neck and heel, as conventionally regarded as vulnerable to earthquakes, the upstream and downstream surfaces may also suffer from severe damage, resulting in cracks cutting through the dam. More occurrence of this failure mode is observed when the input acceleration amplitude intensifies. This research is expected to provide more insights into the weak links of the dam when subjected to earthquake shocks and thus leads to more efficient aseismic measurements.
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