考虑耦合效应的混凝土重力坝水压致裂分析

摘要

考虑裂缝在水力劈裂过程中涉及到库水和混凝土之间的渗流—应力耦合效应,导出了水压致裂的渗流—应力耦合控制方程的强、弱形式,采用ABAQUS中的“虚拟节点”实现水压致裂的数值模拟,研究了影响混凝土重力坝水压致裂的主要因素.结果表明,在水压致裂过程中,裂缝张开位移和裂缝口的水压力出现先增加到峰值然后下降并趋于稳定的特性,注水流率越大峰值越大,渗透系数越大峰值越小,液体动力黏度的不同对裂缝的扩展也有影响.最后,对沿着建基面的孔隙水压力与竖向位移的变化进行了分析.%Both strong and weak form governing equations of hydraulic fracturing are derived considering seepage-stress coupling,a model of concrete gravity dam with initial crack is studied by combining XFEM and "Phantom node" method using ABAQUS,the main factors affecting the water pressure fracturing of concrete gravity dam were also studied in the paper.Result shows that,during the hydraulic processing the crack opening displacement and crack mouth pressure increasing nonlinear at different water injection rate with time step while decreasing nonlinear at different permeability,and showing a tendency that after reached the peak value the solution becomes convergence.The difference of liquid dynamic viscosity also affects the crack propagation.In the end,the variation of pore water pressure and vertical displacement along the base surface were also analyzed.