梯形掏槽护拱技术在浅埋冲沟淤泥地层隧道洞口进洞施工中的应用

Application of Trapezoidal Cutting and Arch Protection Technology in the Construction of Tunnel Entrance in Shallow Buried Silt Stratum with Gully

隧道进洞施工通常采用超前大管棚等超前加固支护措施及复杂开挖工法,施工难度大。尤其在浅埋、软弱围岩、冲沟发育的复杂地形地质条件下,隧道开挖进洞难度更大,工期、安全和质量都难以得到保证。依托重庆渝武高速公路东阳隧道,应用梯形掏槽加护拱开挖工法,取消了原设计长管棚及双侧壁导坑开挖方法,成功解决了浅埋软质围岩等复杂地质条件下隧道洞口安全进洞技术难题,大大提高了工效,保证了隧道施工安全和质量。

Advanced reinforcement and support measures such as advanced pipe-roof and complex excavation method are usually adopted in tunnel construction,which is difficult to construct.Especially in the complex topographical and geological conditions with shallow depth,weak surrounding rocks and gully development,it is more difficult to excavate the tunnel portal section,and the construction period,safety and quality are difficult to be guaranteed.Based on Dongyang tunnel on Chongqing-Wuhan Expressway,the trapezoidal cutting and arch protection method is used to eliminate the original design scheme of long pipe-roof and double-side drift method,successfully solving the technical difficulties of tunnel portal construction in the shallow-buried and soft surrounding rock conditions,greatly improving the work efficiency,guaranteeing the tunnel construction safety and quality.