向家坝地下电站引水洞渗压异常分析及处理

摘要

After the operation of Xiangjiaba underground power station , it was discovered that the seepage pressure in the sur-rounding rock of the diversion tunnel was too high , and the seepage and damp exist in the partial side walls at upstream of the main power house .Through the analysis on the design and construction situation of the diversion tunnel , it is concluded that the un-cover grouting adopted for overlap of curtain leads to the insufficient anti -seepage of the orifice .The comprehensive mainte-nance measure of blockage in the front and draining at the back is used and the construction process of blockage and draining is introduced.The operation after the maintenance shows that the problems such as the abnormal seepage pressure of the diversion tunnel and the seepage in the main power house can be solved by the above measure .%向家坝地下电站投运后发现引水洞围岩渗压偏高，主厂房部分上游边墙存在渗水或潮湿现象。通过分析引水洞设计及施工情况认为，洞内搭接帷幕采用无盖重灌浆，导致孔口段防渗效果欠佳。经研究，决定采用“前堵后排”的综合检修措施，并介绍了堵水及排水措施的具体施工过程。检修后引水洞的运行情况表明，该措施能够较好解决引水洞渗压异常和主厂房的渗水问题。