复合土工膜防渗土石坝渗流安全监控指标拟定

复合土工膜作为一种质轻、强度高、价廉的防渗材料,应用于大型水库防渗工程时,需监测其防渗效果。以西霞院反调节水库复合土工膜斜墙防渗砂砾石坝为例,根据历史监测资料,考虑库水位、温度、降雨、时效的影响构建渗流统计模型,分别采用置信区间法与典型小概率法拟定膜后渗流安全监控指标。结果表明膜后渗压水位较低,总体上无明显变化趋势,复合土工膜防渗效果明显。采用置信区间法拟定该工程大坝渗流安全监控指标更合理,可实时监测渗流安全状态,提供准确预警,保障大坝安全稳定运行。

Establishment of Seepage Safety Monitoring Index for Composite Geomembrane Impervious Earth Rockfill Dam

Composite Geomembrane is a kind of light,high strength and low-cost anti-seepage material.When it is applied to the anti-seepage project of large reservoir,it is necessary to monitor its seepage control effect.Taking the composite geomembrane inclined wall anti-seepage sand-gravel dam of Xixiayuan anti-regulating reservoir as an example,according to the historical monitoring data,the seepage statistical model was constructed considering the influence of reservoir water level,temperature,rainfall and age effect.The confidence interval method and the typical small probability method were used to formulate the safety monitoring index of the seepage flow behind the membrane.The results show that the seepage water level behind the membrane is low and has no obvious change trend on the whole,and the composite geomembrane has obvious anti-seepage effect.It is more reasonable to use confidence interval method to draw up dam seepage safety monitoring index,which can monitor the seepage safety status in real time and provide accurate warning as well as ensure the safe and stable operation of the dam.