浅埋超大跨四线隧道Ⅴ级围岩开挖关键参数研究  

Study on Key Excavation Parameters of Shallow Super-large-span Four-track Tunnel Under Grade-V Surrounding Rockmass

作　　者：刘夏冰 王雨 王文谦 贺少辉[4] 麻建飞 LIU Xiabing;WANG Yu;WANG Wenqian;HE Shaohui;MA Jianfei(Guangdong Hualu Transport Technology Co.,Ltd.,Guangzhou 510420,China;School of Architecture and Civil Engineering,Liaocheng University,Liaocheng 252059,China;China Railway Engineering Design and Consulting Group Co.,Ltd.,Beijing 100055,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]广东华路交通科技有限公司,广州510420 [2]聊城大学建筑工程学院,山东聊城252059 [3]中铁工程设计咨询集团有限公司,北京100055 [4]北京交通大学土木建筑工程学院,北京100044

出　　处：《铁道标准设计》2024年第7期132-140,共9页Railway Standard Design

基　　金：广东省重点领域研发计划资助项目(2022B0101070001);中铁大桥局集团第四工程有限公司资助项目(CL19048530)。

摘　　要：为适应城市地形及高铁选线需求,部分线路需以四线超大跨度隧道的形式面临浅埋、Ⅴ级围岩等客观条件,目前缺乏对此类隧道的规范指导,应重点关注其开挖安全。以杭台高铁下北山隧道为工程依托,采用现场测试方法研究其围岩变形、初期支护受力特征,通过三维数值模拟方法对多组工法进行开挖模拟,总结得出浅埋四线高铁隧道Ⅴ级围岩的开挖关键参数。结果表明,采用双侧壁导坑法的拱顶沉降主要发生在各导洞上台阶开挖阶段,中部岩柱开挖对拱顶沉降的贡献为62.2%;依托工程喷射混凝土结构和型钢拱架的安全性均满足施工要求,当前初期支护的安全富余较多;双侧壁导坑法对围岩变形控制效果较好,但三台阶法的围岩应力分布均匀,初期支护的安全系数也满足要求;考虑到原设计双侧壁导坑法存在较多临时支护,为提升施工效率,宜在保障围岩稳定的前提下减少开挖分部数量,探索将双侧壁导坑法优化为少临时支护的三台阶法。In order to adapt to the urban terrain and select high-speed railway line,some lines have to be constructed in shallow and grade-Ⅴrockmass,and there is a lack of regulatory guidance for such tunnels in currently specifications.The key excavation parameters of these tunnels should be studied.The mechanical response of shallow super-large-span four-track tunnel is studied by using field test based on the background of Xiabeishan tunnel in Hangzhou-Taizhou High-speed Railway,and the key excavation parameters under grade-Ⅴrockmass are summarized by carrying out numerical simulation.The result shows that the vault settlement induced by double side drift method(DSDM)mainly occurs at the excavation phase of the upper benches,and excavation of central rock pillar has the most contribution of 62.2%to the vault settlement.The load-carrying capability of shotcrete structure and steel arch meets the safety requirements,and initial support has surplus safety capability.DSDM has a better control effect on rockmass deformation,but the stress distribution of surrounding rockmass induced by the three-bench method is more uniform,and the safety factor of the initial support is also reasonable.Considering that DSDM could cause a low construction efficiency due to the temporary supports,it is advisable to explore the optimization of the DSDM into the three-bench method for improving the construction efficiency.

关 键 词：浅埋隧道 超大跨度隧道 Ⅴ级围岩 开挖关键参数 分部开挖 现场测试 数值模拟 

分 类 号：U452[建筑科学—桥梁与隧道工程]