超浅埋富水全风化花岗岩大断面隧道施工技术

新建沪昆客专湖南段磨把公隧道出口段近800 m为连续浅埋全风化花岗岩,施工采用常规的短台阶工法,超浅埋和强富水地段采用袖阀管注浆和井点降水预加固,加强开挖支护参数等措施,有效控制了变形沉降和坍塌事故发生。在此基础上,研究总结了全风化花岗岩变形规律,提出了预防与控制措施,可为同类工程施工提供参考。

Construction Technology of Ultra Shallow Water Rich Fully Weathered Granite and Large Section Tunnel

There is about 800m of continuous shallow buried fully weathered granite at the exit of The Mobagong Tunnel in Hunan section of Shanghai-Kunming Passenger Dedicated Line, for which short benching tunneling method of construction is adopted. In the super shallow buried and water rich section, sleeve valve pipe grouting, well-points dewatering are used to strengthen the excavation support parameters. These methods enable the effective control of the deformation and collapse accident. On this basis, this paper makes study on deformation law of the fully weathered granite, and put forward preven-tion and control measures, which can provide a reference for similar engineering construction.