百店隧道第三系富水砂层快速施工关键技术研究

以山西中南部铁路通道百店隧道第三系富水砂层快速施工技术为例,根据砂层的物性参数及成因,采取理论和现场试验总结,合理优化注浆工艺,针对超前注浆加固方式、钻孔泄水降压,局部补充注浆及快速开挖封闭技术进行重点研究,提出"超前周边注浆+掌子面加筋注浆+加固体外超前泄水降压+开挖过程中补充注浆+快挖快封"的快速施工关键技术,不但能有效控制开挖过程涌水、流沙、工作面坍塌失稳现象,还可在一定程度上提高综合施工效率,节约施工成本。通过实践证明,具有较好的经济和社会效益,值得类似工程借鉴。

Key Technologies for Rapid Construction of Baidian Tunnel in Tertiary Water-rich Sand Strata

Case study is made on the construction of Baidian tunnel in Tertiary water rich sand strata. First, the grouting technology is optimized on basis of the physical parameters of the sand strata and by theoretical and field tests; Then, study is made on the pattern of consolidation by means of advance grouting, water pressure reducing by water releasing through boreholes, supplementary grouting at local positions, and rapid excavation and rapid closing; Finally, key rapid construction technology, including advance periphery grouting, reinforced grouting at tunnel face, water pressure reducing by water releasing, supplementary grouting during excavation, and rapid excavation and rapid closing, is proposed. The technology proposed has been used in the construction of Baidian tunnel. Not only the water outburst, sand outburst and the tunnel face stability have been brought under effectively control, but also the comprehensive construction efficiency has been improved and the construction cost has been reduced. 