浅埋偏压软弱围岩隧道口治理

以某隧道为例,采用砂浆锚杆配合小导管注浆加固边仰坡、偏压处反压回填、地表注浆配合管棚成型、台阶法预留核心土开挖、洞内拱部超前小导管注浆、径向小导管注浆及临时仰拱支护等多项综合进洞施工技术,且在施工中加强监测,保证施工安全、加快工程进度、提高劳动效率并确保该隧道运营阶段的安全。及早施作初期支护和二次衬砌控制围岩变形,保护和发挥围岩自承载能力,确保洞口坡体稳定。

Research on Construction Technology of a Tunnels Entrance Shallow Buried and Unsymmetrical Loaded through Strata of Fractured Zone

By means of strengthening the monitoring and measurement, technical problems of this tunnel, such as mortar bolt with a small catheter grouting slope around, the backfill pressure in unsymmetrical loaded zone, surface pre-groution coordinated with pipeshed, reserved the core soil excavation, pre-grou- ting and temporary supporting of invert, were successfully solved on excavation construction technology. Reinforcing effect and observational method had been showed by analyzing monitoring data such as the ground settlements, the vault subsidence, and the horizontal convergence. The results show that those measures taken ensure the safety of construction and accelerating the progress of the projects, improved la- bor efficiency and the operational phase of tunnel safety, and it is the sooner the better for application of primary support and the secondary lining, which are to control deformation, to protect and develop the carrying capacity by itself, to ensure entrance slope stability.