软岩隧道辅助坑道挑顶进正洞力学转换机制及施工技术

Stress transformation mechanism and roof-ripping constructionof service gallery into main tunnel in soft rock tunnel

长大山岭隧道普遍采用辅助坑道实现长隧短打。软岩隧道辅助坑道挑顶进正洞施工风险高、难度大,是安全生产的重点管控环节。针对软岩隧道辅助坑道挑顶进正洞施工的经验教训,从施工工序和力学机制两个方面进行研究,讨论了软岩隧道辅助坑道进正洞的重难点、关键技术控制点及力学转换机制,提出了“地层预加固、开挖短进尺、支护大刚度、变形勤量测”的辅助坑道进正洞挑顶施工原则。

The service gallery is commonly used in the construction of long tunnels in mountainous areas to achieve the goal of constructing a long tunnel in a short period of time.However,the roof-ripping construction of service gallery into main tunnel in soft rock tunnel is risky and difficult,and it is a key control point for safety production.Based on the lessons learned from the roof-ripping construction of service gallery into main tunnel in soft rock tunnel,this study focuses on the construction process and mechanical mechanism,and discusses the key difficulties,key technical control points,and mechanical transformation mechanism of the service gallery into main tunnel in soft rock tunnel.The study proposes the construction principles of"pre-reinforcement of the stratum,short excavation distance,strong support,and frequent deformation measurement"for the construction of the roof-ripping construction of service gallery into main tunnel in soft rock tunnel.