在重力坝设计中,由于应力集中的影响以及温度、收缩和渗透压力作用,难于保证坝面不存在拉应力的要求,这就出现了受拉区是否开裂以及开裂后是否稳定问题.当前已开始探讨用脆性断裂力学研究这些问题. 本文主要是用光弹性涂层法通过模型试验来研究混凝土重力坝坝踵开裂后(不同的裂纹角和缝长)缝端的复合型应力强度因子和破坏方向角. In the design of gravity dam, due to the influence of stress concentration and temperature, shrinkage and osmotic pressure, it is difficult to ensure that there is no tensile stress in the dam surface, which leads to the problem of whether the tension zone is cracked and stable after cracking. In this paper, we use brittle fracture mechanics to study these problems.In this paper, we use the model of photoelastic coating to study the composite stress intensity factor and failure direction angle (different crack angle and slot length) at the crack tip of concrete gravity dam .