富水冰碛体中水工隧洞水平旋喷桩预支护施工技术

Horizontal Jet Grouting Pile Support in Construction of Hydraulic Tunnel in Water Rich Moraine Deposit

在水电站引水隧洞施工过程中,针对富水冰碛体特殊地层采用了水平旋喷桩预支护技术,即在隧洞拱顶及周边形成封闭的水平旋喷帷幕体,利用水平旋喷桩的阻水效应和土体改良加强效应起到对拱顶围岩超前预加固作用.该项技术在布伦口～公格尔水电站引水隧洞第四系冰碛体地层中的成功应用,拓展了水利水电工程特殊地质条件下地下工程安全施工技术领域,可为类似工程施工提供借鉴.

During construction of headrace tunnel in hydropower station,horizontal jet grouting support is used in water rich moraine deposit. A closed and horizontal jet grouting curtain is formed in tunnel crown and its periphery. By take advantage of water resistance effect of horizontal jet grouting piles and reinforcing effect of soil improvement,advance reinforcement for surrounding rocks in tunnel crown is provided. This technology was successfully applied in construction of headrace tunnel in Quaternary moraine deposit at Bulunkougonggeer hydropower station,which extends field of safe construction technology for underground project under special geological conditions in hydropower projects,providing references for the similar projects.