Abstract: Seepage bringing out sand from structural joints of the gallery on dam block No.10~11 of Tongjiezi dam was a major problem threatened the safety operation. To ensure operation safety, during the second periodical inspection, cause reasons for seepage were analyzed and treatment scheme as well as construction technology were optimized. Water pressure test was replaced by closed water test to find leakage position. Followed, low pressure inclined-borehole grouting technology combined with rated weight grouting was adopted to stop the slurry and seal the structural joint. Then, LW/HW soluble polyurethane grouting was carried out. The construction technology solved difficulties such as difficult control of the water pressure test, large vertical deviation of structure joint, the small construction site in gallery, slurry leaking in grouting and the bad treatment effect at earlier stage. The fact that the seepage amount dropped from 180 L/min to 0 L/min proved the good effect of the treatment.

摘要： 铜街子水电站大坝廊道10~11号坝段结构缝自工程运行以来一直存在漏水（挟沙）问题，为工程主要安全隐患，长期困扰运行管理单位。为确保大坝安全运行，大坝二轮定检时，工程处理单位与管理单位对漏水原因进行了多方面分析，优化处理方案与施工工艺，改压水试验为闭水试验查找漏水部位，采取坝后斜钻孔低压灌浆与定量灌浆技术对结构缝进行止浆封闭处理，最后在廊道内对漏水部位进行LW/HW型水溶性聚氨酯灌浆施工，解决了压水试验难以控制、结构缝铅直度偏差大、廊道施工场地狭小、灌浆时多处漏浆及前期结构缝漏水处理效果差等难点。结构缝处理