白鹤滩水电站蓄水过程左岸厂区渗控效果评价

白鹤滩水电站左岸地质条件复杂，发育层间错动带、层内错动带和柱状节理玄武岩等软弱地质结构。左岸厂区布置大规模的防渗排水系统，合理有效地评价其渗控效果对水电站的安全运行有着重要的指导意义。结合2021年4月—2022年3月蓄水过程的监测成果分析白鹤滩水电站左岸厂区渗流规律，评价渗控效果。结果表明：左岸厂区最大渗流量为1249.14 L/min，总渗流量明显受上游水位变化影响，第3、7层排灌廊道渗流量占总渗流量的69.5%。防渗帷幕部位的压力水头随高程的降低而增加，C₂位置压力水头明显增大。结构面C₃、C_3-1、C₂和LS₃₁₅₂是渗透薄弱部位，其渗流量较大，渗压水位随上游水位变化明显，容易成为渗漏通道。从整体上看，厂区的排水孔幕能有效消减压力水头，总渗流量维持在合理范围内，总体渗控效果良好。

Evaluation of seepage control on left bank of Baihetan hydropower station during impoundment

Geological conditions on the left bank of the Baihetan hydropower station are complicated due to its interlayer dislocation zones, intra-layer dislocation zones, columnar jointed basalt, and other weak geological structures. A large-scale seepage-control and drainage system was arranged in the left bank plant area. Reasonable and effective evaluation of its seepage control effect is of great significance to guiding the safe operation of the station. This paper presents an analysis of the monitoring data from the system and its control effect during the impoundment from April 2021 to March 2022. The results show that the total seepage flow, with a peak of 1249.1 L/min, is significantly affected by the change in the upstream water level, and 69.5% of it is contributed by the seepage through the drainage and irrigation corridors on the third and seventh floors. Pressure head at the anti-seepage curtain rises with the decrease in elevation, with a significant rise at C2. The structural layers C3, C3-1, C2 and LS3152 are more permeable and subjected to larger seepage flows, so that they respond more sharply to the changes in the upstream water level and are prone to seepage channel formation. On the whole, the drainage curtain can effectively reduce the pressure head and maintain the total seepage flow within a reasonable range, achieving a good effect of overall seepage control.