以一个双曲拱坝为实例 ,用三维断裂分析边界元法和最小应变能密度因子理论研究了高拱坝上游坝踵裂缝稳定性及扩展的情况。结果表明 :缝的稳定性与初始裂缝的出现高程有关 ;水力劈裂是造成初始裂缝扩展的主要原因 ;地基刚度将影响对裂缝稳定性的判断 ;当裂缝达到一定深度后 ,裂缝将显著削弱拱坝的受力截面。验证了在基本荷载组合下 ,拱坝坝踵裂缝的稳定性 ,并计算了在极端不利条件下 ,拱坝坝踵裂缝可能扩展的轨迹 Taking a hyperbolic arch dam as an example, the fracture stability and propagation of the upper dam heel of the high arch dam are studied by the three-dimensional fracture analysis (BEM) method and the minimum strain energy density factor theory. The results show that the stability of the seam is related to the elevation of the initial crack. Hydraulic fracturing is the main reason for the initial crack propagation. The stiffness of the foundation will affect the judgment of the fracture stability. When the fracture reaches a certain depth, the crack will significantly weaken the arch Dam section of the force. The stability of the crack at the heel of the arch dam is verified under the combination of the basic load and the trajectory of the crevice of the heel of the arch dam under extreme adverse conditions is calculated