积石峡面板堆石坝复杂渗流场有限元精细模拟

运用自主研发的三维渗流有限元可视化分析软件GWSS，对积石峡面板堆石坝的坝体（包括面板、过渡层、排水层、堆石料等）、坝基、防渗帷幕以及泄洪洞和底孔排沙洞等结构进行了精细建模。在此基础上采用求解有自由面的改进截止负压法、隧洞子结构法和求解大型稀疏矩阵的预处理共轭梯度算法对积石峡面板堆石坝复杂渗流场进行了数值模拟。重点研究了面板和防渗帷幕联合作用下渗流场分布特征和防渗效果，以及泄洪洞和底孔排沙洞对大坝渗流场的影响等。计算结果表明，在正常运行条件下，面板结合防渗帷幕能够起到很好的防渗作用，坝体内自由面较低，左岸底孔排沙洞和泄洪洞也起到了很好的排水作用，大大降低了左岸山体的地下水位，有利于大坝和岸坡的稳定。

Finite element fine simulation of complicated seepage field of concrete face rockfill dam of Jishixia

Using the visualization finite element analysis software "Ground Water Simulation System"(GWSS),we conduct precise modeling of Jishixia concrete face rockfill dam.It covers the modeling of dam body(concrete face,transition layer,drainage layer,rockfill materials),dam foundation,anti-seepage curtain,spillway tunnel and bottom desilting tunnel.Numerical simulation of the complicated seepage field is performed by improved cut off negative pressure method with free surface evolution,tunnel substructure and Preconditioned Conjugate Gradient algorithm for solving large sparse matrix.Seepage distribution characteristics and seepage control effect for the combination of concrete face and anti-seepage curtain as well as the influence of spillway tunnel and bottom desilting tunnel on the seepage flow in the dam are studied.Numerical simulation results show that,the combination of concrete face and anti-seepage curtain does well in seepage control under normal operation condition.Meanwhile,the bottom desilting tunnel and spillway tunnel on the left bank play a positive role.They reduce the groundwater level of left bank significantly and are favorable to the stability of the dam and bank slope.