第三系富水粉细砂VI级围岩隧道浅埋下穿水库施工技术

Construction Techniques for a Shallow-Depth Tunnel of Type-VI Watery Fine-Sand Surrounding Rock Passing Under a Reservoir

兰渝铁路胡麻岭隧道5#斜井正洞段落遇到第三系富水粉细砂地层浅埋下穿水库施工,因而隧道塌方、变形、突水涌泥风险高。施工中采用地表旋喷桩固结隧道洞身围岩,辅以综合降水、双液浆局部加固、CRD交叉中隔壁法开挖等措施,并配以严密的内外监测技术,安全顺利通过此段落。

The construction of the section of the right cavity of the fifth shaft of the Humaling Tunnel of the LanzhouChongqing Railway involves the shallow-depth tunnel passing under a reserve through the Tertiary watery fine-sand stratum,in which case there is a high risk of collapse,deformation,water inflow and mud gush.In the course of the construction of such a section,the rotary-jetting pile is used to solidify the surrounding rock of the tunnel,with the techniques of the comprehensive precipitation,double-liquid local consolidation,and the CRD intercrossing-and-inter-blocking-wall excavation adopted for the construction and the internal and external monitoring techniques applied to helping the construction.