地质缺陷的面板堆石坝渗流特性分析及处理措施研究

Study on Seepage Characteristics and Anti-seepage Measures for CFRD with Geological Defects

新疆某水电工程地质条件复杂,层面及构造发育,左岸坝基存在断层构造,水平宽度达0.5 m且上下游贯通,左岸坝肩存在宽5 m的白云岩溶蚀带,溶穴较为发育。根据坝址区地质地形特性,建立了工程坝址区三维有限元渗流性态分析模型,模拟了溶蚀带和大断层等重要地质构造,采用改进折算渗透系数法以精确模拟溶蚀带的渗透性,分析了左岸白云岩溶蚀带和F4断层地质缺陷对坝址区渗流性态的影响,研究了采用不同深度混凝土洞塞处理溶蚀带的防渗效果,开展了断层渗透参数敏感性分析,提出了白云岩溶蚀带采用混凝土洞塞截渗及断层采用混凝土帷幕灌浆的防渗处理方式。

A hydropower project in Xinjiang has complex geological conditions. A fault structure （F4） passes through the upstream and downstream with 0.5 m width in the left bank of dam foundation, and a developed dolomite karst zone with 5 m width also passes through the left abutment of dam. According to geological and topographical characteristics of dam foundation, a three-dimensional finite element model is established for analyzing the seepage characteristics of dam. In this model, the fault structure and developed dolomite karst zone are simulated, and the improved converting permeability coefficient method is applied to simulate the permeability of dolomite karst zone. The influences of these geological defects on dam seepage characteristics are analyzed. The anti-seepage effects of concrete plug with different depths in dolomite karst zone are studied. The sensitivity of penetration parameter of fault is also analyzed. The anti-seepage methods by using concrete plug in dolomite karst zone and concrete curtain grouting for fault are finally proposed.