混凝土防渗墙开裂对坝基渗透稳定性的影响

Effects of cracking of anti-seepage concrete wall on seepage stability of dam foundation

采用渗流有限元方法分析混凝土防渗墙开裂对坝基土体渗透稳定性的影响。以冶勒水电站工程为例,分析在坝基地层地质条件复杂、各岩层的渗透特性差别较大的情况下,在坝基混凝土防渗墙开裂时,坝基覆盖层各土层渗透破坏区的范围,同时还对坝基渗透破坏区域进行了渗透扩展过程分析。计算结果表明:若防渗墙不开裂,设计防渗工况能满足工程安全要求,若防渗墙开裂,则坝基土体可能会发生渗透破坏,而且防渗墙裂缝宽度和条数对坝基渗透稳定性和渗透破坏区范围的大小有重要影响。

A case study on the Yele Hydropower Station was performed by use of the finite element method. In consideration of the complicated geological condition of the dam foundation and great differences in seepage property of different rock strata, the ranges of seepage failure zones in different soil layers of ovedying strata of the dam foundation were analyzed when the cracking of the antiseepage wall occurred, and the seepage extension in these zones was also discussed. The result shows that the anti-seepage property of the concrete wall can meet the safety requirement of the project when the cracking of the anti-seepage wall does not occur, however, the cracking of the anti-seepage wall might result in seepage failure in soll layers of the dam foundation. It is also indicated that the number and width of cracks are of great influences on the seepage stability and ranges of seepage failure zones of the dam foundation.