郭旗隧道明挖改暗挖施工技术

Construction Technology of Changing from Open Excavation to Underground Excavation in Guoqi Tunnel

文章介绍了蒙华铁路郭旗隧道明挖改暗挖施工技术。穿越浅埋冲沟地段,原设计埋深4.5~6m,现场实测地形隧道埋深已达到13.04m,经方案筛选,采用先清理该地段表层土,随后对该段采用高压旋喷桩进行地表加固,最后在隧道顶部土体形成有一定自稳能力的覆盖层后进行隧道暗挖支护成型。施工实践表明该施工方法合理、安全有效,对明挖改暗挖或浅埋隧道施工提供有益借鉴。

The article introduces the construction technology of the open excavation to the undercut excavation of the Guoqi Tunnel on the Menghua Railway.The original design buried depth crossing the shallow gully section is 4.5~6m,and the measured terrain tunnel buried depth has reached 13.04m.After the plan is screened,the surface soil of the section is cleaned first,and then high-pressure jet grouting piles are used for surface reinforcement,and finally,after forming a self-stabilizing cover layer on the top of the tunnel,the tunnel is undercut and supported.The construction practice shows that the construction method is reasonable,safe and effective,and it can provide a useful reference for the construction of open excavation to underground excavation or shallow buried tunnel construction.