川东北红层水平软岩地区浅埋隧道开挖方式研究  

Study on Excavation Methods of Shallow Buried Tunnels in the Horizontal Soft Rock Area of Red Layer in Northeast Sichuan

作　　者：李立辉[1] LI Lihui(China Railway 18th Bureau Group Corporation Limited,Tianjin 300222,China)

机构地区：[1]中铁十八局集团有限公司,天津300222

出　　处：《铁道建筑技术》2024年第6期149-152,共4页Railway Construction Technology

基　　金：中铁十八局集团有限公司科技研究开发计划项目(G20-53)。

摘　　要：川东北地区的红层软岩是一种特殊性岩土,浅埋段隧道施工围岩易出现较大变形甚至塌方。为保障类似工程施工顺利进行,依托汉巴南铁路南充至巴中段HBNZQSG-4标段玉龙山隧道工程,对该地区典型红层水平软弱围岩隧道开挖方式和变形破坏模式进行研究,并结合数值模拟结果,提出围岩变形有效控制措施。研究结果:红层软岩隧洞拱顶位移先增大后略微减小最后趋于稳定;采用全断面法开挖无法保证施工安全;采用台阶法施工对围岩扰动相对较大,但台阶法开挖有卸荷作用,利于缓解过大的应力集中现象,在限制围岩变形的同时亦可降低锚杆应力。The red soft rock in northeast Sichuan is a special type of rock and soil,and the shallow buried tunnel is prone to large deformation or even collapse of the surrounding rock during construction.In order to ensure the smooth progress of the construction of similar projects,relying on the Yulongshan Tunnel Project of HBNZQSG-4 Lot of the Nanchong to Bazhong section of the Hanzhong-Bazhong-Nanchong High-speed Railway,the excavation method and deformation failure mode of the typical red layer horizontal weak surrounding rock tunnel in the area were studied,and combined with the numerical simulation results,effective measures to control the deformation of the surrounding rock were proposed.Research results are as follows:the displacement of the red layer soft rock tunnel vault increases first,then decreases slightly,and finally stabilizes;the construction safety cannot be guaranteed by the full-section method excavation;the disturbance of the surrounding rock during the construction of the tunnel using the step method is relatively large,but the step method excavation has the effect of unloading,which is conducive to alleviating the excessive stress concentration and simultaneously limiting the deformation of the surrounding rock and reducing the stress of the anchor rod.

关 键 词：铁路隧道 红层水平软岩 变形特征 台阶法 全断面法开挖法 控制措施 

分 类 号：U455.49[建筑科学—桥梁与隧道工程]