盖挖法在重罗山隧道浅埋偏压段的应用

Application of Cover-excavation Method in Shallow-buried and Biased Section of Chongluoshan Tunnel

针对重罗山隧道左线出口段与V形冲沟斜交下穿和最小埋深2.47 m的工程特点,采用盖挖法施工。运用数值模拟方法,分析隧道受力、变形的变化规律,总结了浅埋偏压段盖挖法施工要点。结果表明:在隧道浅埋偏压段用盖挖法施工,可避免大面积明挖对生态环境的破坏,又规避了隧道冒顶坍塌的危险,同时对缩短工期、保证质量等都有积极的作用,是浅埋偏压隧道最佳的施工方案。

Aiming at the project characteristics of left line exit section of Chongluoshan tunnel and V-shaped gully oblique crossing underneath and the minimum buried depth of 2. 47 m,the cover-excavation method was adopted. The numerical simulation method was adopted to analyze the changing mechanism of force and deformation of tunnel. Meanwhile,key construction points for shallow-buried and biased section coverexcavation method were summarized. The results show that the cover-excavation method can avoid the damage of large area open excavation to the ecological environment and evade the danger of tunnel roof falling,which could maximize the protection of ecological environment,at the same time,have positive effects on shortening the construction period and ensuring quality,which is the best construction program in shallow buried and biased section of the tunnel.