为研究土工膜缺陷的面膜坝在库水位骤降情况下的渗流特性以及上游坝坡的稳定性,利用Geo-slope软件建立了破损土工膜有限元分析模型,对土工膜不同破损部位以及破损尺寸进行了渗流要素和稳定性分析。结果表明:土工膜破损位置越高,尺寸越大,浸润线抬升越高,渗漏量越大,但后者影响明显小于前者;当库水位高程降落至土工膜破损高程时,存在一个浸润线突然下降的“突变”初始稳定安全系数随着土工膜缺陷位置的变高和尺寸的变大而变小,安全系数总体上呈现先下降,后趋于稳定的规律,但在库水位高程经过土工膜缺陷处,存在一个突然上升的过程。研究成果为面膜坝运行过程中的稳定性评价和治理提供了参考。

In an attempt to study the seepage characteristics of geomembrane dam with geomembrane defects and the stability of upstream dam slope under rapid drawdown of reservoir level,a finite element model of damaged geomembrane was established to analyze the seepage factors and stability of dam with different damage parts and sizes of the geomembrane. Results revealed that the higher the damaged position of geomembrane and the larger the size, the higher the phreatic line and the greater the leakage; the impact of damage size was obviously smaller than that of damage position. The phreatic line declined abruptly when the water level of the reservoir reduced to the height of the geomembrane. The initial stability safety factor decreased with the increase of the height and size of the defect position. In general, the safety factor decreased first and then stabilized, yet with a sudden rise when water level reached the geomembrane defect. The results provide a reference for the stability evaluation and treatment of geomembrane dam.