Abstract: Fault F2 went through the dam foundation with angle 70°with the axis of right abutment of auxiliary dam and 90 m wide. The fault was mainly composed of mudstone and sandstone with low compressive strength and high content of soluble salt. As erosion of groundwater to portland cement, the effect of original foundation impervious curtain was declined. To prevent seepage water spread along fault F2 to downstream and affect the stability of south slope, plastic concrete cut-off wall was adopted. The paper introduced the design, construction, pre-drilling and quality control of the cut-off wall, for reference.

摘要： 克孜尔水库F2 断层与副坝右坝肩轴线呈70°夹角穿越坝基，影响宽度约90 m。由于该断层带基岩主要以泥岩、沙岩为主，遇水易软化，饱和抗压强度低，且基岩易溶盐含量较高，水库蓄水后地下渗水形成的环境水对普通硅酸盐水泥有强侵蚀作用，导致原基础帷幕防渗体防渗效果下降。为防止渗水沿F2 断层带继续向下游扩散，影响方山南岸坡稳定，经方案比选后确定进行塑性混凝土防渗墙加固。本文从防渗墙设计、试验段及其他槽段施工、混凝土底板预钻措施、施工质量控制等方面进行了总结，可为类似工程提供借鉴和参考。