Treatment Measure Study On Water Burst Of Diversion Tunnelin Jinping Stage2Hydropower Station

Water burst is one of the most common phenomenon in tunnel construction. And it not only bring difficulties during work progress, but also leads damages to engineering project. In seriously situation, it may cause suspension of work. Prevention methods on water burst are drainage and sealing. This paper takes water burst phenomenon in tunnel constructions of Dayao Mountain, Laoqingshan and Nanling tunnel as study cases, and discusses the activity characteristics and construction disciplines of groundwater in water tunnel of Jinping Hydropower Station. The analysis results show that:the treatment of F9fault of Dayao Mountain is pre-reinforcement that combined with pre sudden grouts and short pipe roof. The treatments of water burst in broken zone of F7fault of Laoqingshan tunnel is consisted of mud plugging grouting and reinforce layer. The solution of Nanling tunnel is mainly depending on splitting mud grouting with high pressure and long pipe supporting. Meanwhile, this thesis summarized the technology of comprehensive improvement of karst, that is including mud plugging grouting, treatment of crater surface, river diversion, monitoring measurement, information feedback and geological forecasting. The groundwater characteristics in diversion tunnel of Jinping Stage2Hydropower Station are high pressure and regime flow. Based on spy-prevent-drain-control-block, the treatment of water burst is using a combination of cited-row-block. And that can ensure the safety of tunnel construction. The instance analysis sum up the experience and technology of water burst, and provide references for similar tunnel constructions.