基于三维渗流模拟的坝基渗漏和渗透稳定分析--以哇沿水库为例

Three Dimensional Numerical Simulation Researches for Foundation Seepage and Analysis of Seepage Stability: A Case Study of Wayan Reservoir

水库坝基渗漏不但损失水库蓄水量,更重要的会引起大坝渗透变形失去稳定。应用三维地下水流数值模拟计算坝基渗漏量和分析渗透稳定,较好地解决了周边与底面边界的不规则问题和垂向上地层的非均质问题,提高了计算精度。以青海省哇沿水库为例,在充分分析水库坝基水文地质条件的基础上,建立了坝基渗漏三维地下水流数值模型,模拟了设置不同深度防渗墙时的渗漏量和坝后出溢段水力坡度。评价了大坝的渗透稳定性,为防止哇沿水库发生渗透变形,设置防渗墙深度应大于50m。当防渗墙深度为50m时,水库渗漏量为12 012m^3/d。

Dam foundation seepage of reservoir induces the loss of reservoir storage, but more important, it causes dam seepage stability and deformation. This paper used numerical simulation of 3-D groundwater flow to calculate seepage quantity and analyze seepage stability, which has solved the problem of surrounding, bottom boundary of irregular and heterogeneity on vertical sequence well. Meanwhile, the calculation accuracy was enhanced. This study was applied to the Wayan Reservoir in Qinghai Provence. According to the hydrogeological characteristics of dam foundation,a model for the three-dimensional numerical simulation of flow was established to solve the seepage problem of this reservoir. To evaluate the seepage stability of dam, this paper analyzed the leakage quantity and hydraulic gradient of egress section in conditions of different depth of impermeable wall. The results show that the dam foundation of Wayan Reservoir is in the steady seepage state, when the depth of anti-seepage wall is more than 50m. The seepage quantity reach 12 012m^3/d with the depth ofanti-seepage wall is 50m.