中天山隧道超高水压富水破碎带施工方法研究

Tunneling through Water-rich Fractured Zone with Super-high Water Pressure: Case Study on Zhongtianshan Tunnel

为解决南疆吐库二线中天山隧道出口钻爆法反坡施工中突遇的超高压涌水施工难题,采取超前地质预报和隧道涌水量、水压及连通性测试,预测前方地质情况以及涌水变化规律。针对掌子面前方超高水压富水破碎围岩,结合现场施工情况,对超前注浆堵水、涌水掌子面直接排水、隧道进口施工降压泄水洞等方案进行比选,最终确定了超前注浆堵水施工方案,成功突破了中天山隧道6.3 MPa超高压富水破碎段施工,确保了隧道的施工安全。

Water gushing with super-high pressure occurs in the down-slope construction of the exit section of Zhongtianshan tunnel on the second Turpan-Korla railway in Xinjiang,China. Advance geology prediction and tests on the water inflow rate,water pressure and water conductivity are made to forecast the geological conditions ahead of the tunnel face and the variation pattern of the water inflow. Three options,i. e.,advance grouting option,direct water releasing option and option of installing water releasing tunnel from the entrance section of Zhongtianshan tunnel,are proposed to cope with the super-high pressure water-rich fracture zone. In the end,the advance grouting option is adopted and the water-rich fractured zone with 6. 3 MPa water pressure has been successfully tunneled through.