沙牌碾压混凝土拱坝诱导缝开裂研究

根据碾压混凝土拱坝诱导缝构造特点，分别将矩形诱导缝简化为穿透形裂缝和深埋椭圆形裂缝，假定为I型开裂；考虑相邻裂缝的影响．采用虚拟裂缝模型和线弹性断裂力学相结合的方法，建立了诱导缝失稳扩展时的亚临界扩展量和等效应力强度因子的解析表达式．结合碾压混凝土的试验断裂参数，计算了沙牌碾压混凝土拱坝诱导缝的等效强度，并将此结果应用到三维非线性应力场仿真分析中，对沙牌拱坝进行了开裂计算分析．计算结果表明，等效强度可以作为诱导缝的开裂准则．

Study of cracking for induced joints of Shapai RCC arch dam

Based on the characteristics of the induced joints of RCC arch dam, the immerged rectangular cracks are simplified into immerged elliptic cracks and penetrated cracks respectively. And according to the assumption of model I fracture and the effect of adjacent cracks, the formulas for the sub-critical extended length and equivalent stress intensity factor of induced joints are given by the method of FCM and LEFM when induced joints expand unstably. The equivalent strength of induced joints of Shapai RCC arch dam is obtained by the proposed model and the fracture parameters of RCC material from experiments, and the results are applied to the finite element emulation program on the 3-D nonlinear stress field, by which the nonlinear cracking analysis of Shapai RCC arc dam is performed. The comparison between the results from calculation and the results from site survey indicates that the equivalent strength can be used as the fracture criterion for induced joints.