为了了解重力拱坝在水下爆炸冲击荷载下的破坏模式,通过建立混凝土重力拱坝水下爆炸全耦合模型,考虑混凝土高应变率效应,对水下爆炸冲击下重力拱坝动态破坏过程进行了全性能数值仿真,针对重力拱坝的结构特性及受力特点,探讨了大坝在水下爆炸冲击荷载作用下的可能破坏模式及破坏机理。结果表明,重力拱坝抗爆薄弱部位主要位于坝体中上部,坝身下部抗爆性能较强;当炸药在拱冠梁处起爆时,表孔中墩及边墩发生冲切和震塌滑移破坏;当炸药在距右岸1/4拱圈处爆炸时,坝肩发生震塌破坏,影响坝肩抗滑稳定及坝体整体安全性。 In order to understand the failure mode of gravity arch dam under underwater explosion impact load, the dynamic failure process of gravity arch dam under underwater explosion was studied by establishing a full coupling model of underwater explosion of concrete gravity arch dam and considering the effect of high strain rate of concrete. According to the structural characteristics and stress characteristics of the gravity arch dam, the possible failure mode and failure mechanism of the dam under the underwater explosion impact load are discussed. The results show that the weak part of the gravity arch dam is mainly located in the upper part of the dam body, and the antiknock performance of the lower part of the dam body is strong. When the explosive is detonated at the crown beam of the arch, the pier and edge piers are punched and collapsed When the explosives explode at 1/4 arch ring from the right bank, the abutment collapsed and damaged, which affected the stability of the abutment against sliding and the overall safety of the dam.