高拱坝上游坝踵裂缝稳定性及其扩展

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

Stability and propagation of cracks at the heel of high arch dams

A 3 D Boundary Element Method and Minimum Strain Energy Density Factor Theory (S theory) were used to study the stability and propagation of cracks at the heel of high arch dams using a double curved arch dam as a case study. The results demonstrate that the crack stability depends on the locations of the initial cracks and the uplift pressure on the crack surfaces plays a key role in crack propagation. The rock foundation stiffness also affects crack stability. Crack propagation will greatly weaken the effective cross section of the arch dam when the crack is very deep. The results show that the crack at the heel of the arch dam is stable for normal loads. The analytical method was then used to predict the trajectory of the crack propagation for extremely adverse conditions using a multi step extension.