双洞八车道公路隧道机械化双侧壁导坑法施工步距研究  

Research on the Construction Step Distance of Mechanized Double-Side Wall Heading Method for Twin-tube Eight-lane Highway Tunnels

作　　者：崔树坚 刘敏 CUI Shujian;LIU Min(Guangdong Provincial Expressway Development Co.,Ltd.,Guangzhou Guangdong 510623,China)

机构地区：[1]广东省高速公路有限公司,广东广州510623

出　　处：《广东公路交通》2024年第6期41-48,共8页Guangdong Highway Communications

基　　金：广东省科技厅计划项目“高速公路改扩建工程快速安全建设关键技术研究”(2021B1111610002)。

摘　　要：本文针对现行相关规范关于施工步距的要求,分析了大型机械化施工需求与施工步距的矛盾,基于装备作业要求,改造了传统的双侧壁导坑法,提出了适用于V级围岩的双洞八车道公路隧道机械化双侧壁导坑法,以及相应的施工步距要求;开展施工过程的三维数值模拟,从洞周变形、结构受力的角度论证了机械化双侧壁导坑法新施工步距的可行性;最后依托深汕西高速改扩建项目6座隧道,开展现场变形和应力监测,验证了机械化双侧壁导坑法新施工步距的安全性、科学性和可行性。本研究基于大型机械装备作业空间和便利需求,优化传统双侧壁导坑法,形成了机械化双侧壁导坑法,确定其施工步距至少为初支封闭成环、仰拱衬砌、二次衬砌分别距掌子面距离为60m、96m和126m;机械化双侧壁导坑法的三维数值模拟和现场实测表明,在新施工步距下,隧道围岩整体稳定,支护结构安全,满足《公路隧道施工技术规范》(JTG/T 3660-2020)要求。Focusing on the requirements of current relevant specifications on construction step distance,the conflict between the demand for large-scale mechanized construction and the construction step distance was analyzed.Based on the equipment operation requirements,the traditional double-side wall heading method was modified,and a mechanized double-side wall heading method suitable for V-grade surrounding rock was proposed for twin-tube eight-lane highway tunnel,as well as corresponding construction step distance requirements.Three-dimensional numerical simulations of the construction process were conducted to demonstrates the feasibility of the new construction step of the mechanized double-sided wall heading method from the perspectives of the surrounding rock deformation and structural stress.Ultimately,relying on the six tunnels of the Shenzhen-Shantou West Expressway reconstrction and expansion project,on-site deformation and stress monitoring were carried out to verify the safety,scientific validity,and feasibility of the new construction step of the mechanized double wall heading method.Research has shown that based on the working space and convenience needs of large mechanical equipment,the mechanized double-sided heading method formed by the traditional double-sided heading method was optimized,with a construction step distance of at least 60m,96m,and 126m from the primary support ring closure,primary support,secondary lining to the palm face,respectively.The three-dimensional numerical simulation and on-site measurement of the mechanized double-sided wall heading method indicated that with the new construction step,the overall stability of the tunnel surrounding rock and the safety of the support structure meet the requirements of the“Technical Specification for Highway Tunnel Construction”.

关 键 词：机械化双侧壁导坑法 施工步距 数值模拟 现场监测 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]