向家坝水电站左岸坝基破碎岩体渗透变形特性试验研究

坝基岩体的渗透变形特性关系到大坝能否安全运行。针对向家坝水电工程坝基存在的挤压破碎带问题，通过常规的渗透变形试验方法和改进后的渗透变形试验方法，对左岸坝基破碎岩体渗透变形特性进行了全方位的试验，通过综合分析 3 种不同试验方法得到的试验结果，深入研究了坝基破碎带岩体的渗透变形特性。研究表明左岸坝基破碎岩体受扰动越严重，其临界水力坡降值就越小；在分析引起临界水力坡降差异的本质原因后，提出了坝基破碎带的临界水力坡降合理取值建议。

Experimental study on seepage failure characteristics of broken rock mass in dam foundation at left bank of Xiangjiaba Hydropower Project

The seepage failure characteristics of rock mass in dam foundation relate to the safety of dam operation.There is a very serious seepage failure problem in Xiangjiaba Hydropower Project because of the existence of broken rock mass zone.Through the routine and improved methods for seepage failure,tests on seepage failure characteristics of broken rock mass in dam foundation at the left bank of Xiangjiaba Hydropower Project are conducted.The seepage failure characteristics of broken rock mass are deeply studied based on three different types of test methods.The results indicate that the value of the critical hydraulic gradient of broken rock mass in this project depends on the disturbing degree of rock mass.The larger the disturbing degree,the smaller the value of the critical hydraulic gradient.After the analysis of the reasons for the difference of the critical hydraulic gradient,the rational value of the critical hydraulic gradient for different stress states is proposed.