泥砂岩富水隧道基岩裂隙水治理关键技术研究与应用

Key Technologies for Treatment of Bedrock Fissure Water In Muddy Sandstone Water Rich Tunnel Research and Application

泥砂岩富水隧道在开挖支护过程中频繁出现股状水、大面积散水,为了解决基岩裂隙水对隧道施工及营运安全的影响,文章依托郑万高铁小三峡隧道工程实例,对地下水采取“以排为主、堵排结合”的原则进行综合治理,具体措施如下:(1)在开挖后初期支护前对集中出水点进行埋管引排,减少对初期支护混凝土质量的影响;(2)初期支护后采用径向注浆封堵大面积散水,改善围岩裂隙性质,减少衬砌渗漏水风险;(3)初期支护面个别渗漏水点采用钻孔引排,接盲管引入侧沟,进一步引排地下水,提供良好的防水基面;(4)边墙位置增设泄压孔排水,增大纵向排水管的泄水能力,减小边墙水侧压力;(5)隧底增设纵向排水盲管及逆向导水管,有效排除隧底承压水,降低隧底隆起风险。实际工程应用效果表明,采用该技术在泥砂岩富水段进行综合治理,实现了衬砌零渗水,杜绝了隧底翻浆冒泥及隆起风险,促进了泥砂岩富水隧道的设计和施工水平的进一步提高。

In order to solve the influence of bedrock fissure water on the tunnel construction and operation safety,based on the small Three Gorges tunnel of Zhengzhou-Wanzhou high-speed railway,the principle of“drainage first and combination of blocking and drainage”is adopted for comprehensive treatment of underground water in order to solve the impact of bedrock fissure water on construction and operation safety,and the measures are as follows:(1)before initial support installation after excavation,the drainage pipe at centralized water outlet shall be buried and drained to reduce the influence on the quality of the initial support concrete;(2)radial grouting is used to block the scattered water in large area after construction of the initial support so as to improve the surrounding rock crack property and reduce the risk of lining leakage;(3)at some water leakage points on the initial support surface groundwaters are led into the side ditch through the blind pipe to further drain the groundwater and provide a good waterproof base surface;(4)the pressure relief hole is added at the side wall to increase the discharge capacity of the longitudinal drainage pipe;(5)blind pipes for longitudinal drainage and reverse aqueducts are added at the tunnel bottom to effectively drain the confined water and reduce the risk of uplift.Practical application results show it realizes zero water seepage of lining,eliminates the risk of mud pumping at the bottom of the tunnel,and promotes further improvement of the design and construction level of the tunnel.