四川红层区某水库坝址渗漏影响因素

Study on reservoir dam site leakage in Sichuan red layer area,China

探讨四川红层区某水库坝址岩体渗透特性及其造成的渗漏问题,为水库安全建设提供理论依据。基于现场勘察成果,采用解析法和数值模拟法对水库坝址渗漏情况进行了计算分析。该水库位于红层区丘陵峡谷之中,坝址区覆盖层与基岩均属透水岩体,坝基及坝肩存在渗漏与绕坝渗漏问题。该水库坝址总渗漏量约为5.60×10~4 m^3/a,占所在河流多年平均流量的3%以下。2种方法计算结果基本一致,表明在均质介质中能较好预测水库渗漏量。该水库坝址存在轻微渗漏情况,经计算分析地下水渗流对坝基的影响较小。

The seepage characteristics and seepage problems of a reservoir dam site in the Sichuan Province are discussed in order to provide theoretical basis for reservoir safety construction. Based on the achievement of site investigation, combined with the analytical method and numerical simulation, the seepage of red layer in the reservoir dam site is calculated and analyzed. It shows that the proposedreservoir is located in a hilly canyon in red layer of Sichuan Province, and the bedrock and overlying strata in the dam site belong to the permeable rock mass, which raise the possibility of seepage problem in the dam area. The total seepage amount of dam site is about 5.60×10^4 m^3/a, less than the average annual flow of the river by 3 %, and the calculation by both analytical method and numerical simulation method basically yield same result, indicating that the reservoir leakage can be well predicted in a homogeneous medium. Investigation reveals that the leakage in the dam site is slight and the groundwater seepage only has a minor effect on the dam foundation. However, for the safe operation of the reservoir, long term ground water level observation hole should be systematically built in the reservoir area.