Ⅳ级围岩三车道隧道最优锚杆间距分析及研究  

Study on Optimal Anchor Spacing of Class Ⅳ Surrounding Rock Tunnel with Three Lanes

作　　者：王志伟[1] 宋梦阳 金辉[1] 田志宇 吴正恺[1,3] Wang Zhiwei;Song Mengyang;Jin Hui;Tian Zhiyu;Wu Zhengkai(Key Laboratory of Treinsportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu Sichuan 610031,China;Research Institute of Highway Planning Survey and Design,Sichuan Transportation Department,Chengdu Sichuan 610041,China;Shanghai Urban Construction Design & Research Institute (Group) Co.Ltd.,Shanghai 200125,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]四川省交通运输厅公路规划勘察设计研究院,四川成都610041 [3]上海市城市建设设计研究总院(集团)有限公司,上海200125

出　　处：《铁道建筑技术》2018年第12期86-92,共7页Railway Construction Technology

基　　金：国家自然科学基金资助项目(51578456)

摘　　要：以马峦山隧道工程为依托,采用室内模型试验和数值模拟验证的手段对Ⅳ级围岩三车道大断面隧道锚杆间距的最优性进行研究。模型试验结果表明,从不同锚杆间距的各监测点位移变化规律及极限承载力方面来看,锚杆间距0. 5 m×0. 5 m工况与1 m×1 m工况整体差距较小,隧道稳定性较好,且各监测点位移皆小于安全控制基准值;锚杆间距1.5 m×1.5 m工况隧道拱顶、边墙、拱底三个监测点位移值超过规定阈值,处于不安全状态。数值模拟验证分析表明,锚杆间距大于1.0 m×1.0 m时,洞周围岩和衬砌受力均变化明显,洞周位移也在持续变化;但当锚杆间距小于1 m×0. 75 m时,衬砌和拱架受力基本不变,洞周位移也趋于稳定。从围岩变形控制与柔性支护理念出发,考虑经济性,锚杆间距1.0 m×1.0 m～1.0 m×0.75 m为最优区间。Based on the Maluanshan tunnel project, the optimization of anchor spacing of three-lane large-section tunnel in grade Ⅳ surrounding rock is studied by means of indoor model test and numerical simulation. The experimental results show that, from the angle of displacement variation law and ultimate bearing capacity of monitoring points with different anchor spacing, the overall gap between 0. 5m×0.5m and 1m×1m conditions is small, the tunnel stability is good, and the displacement of each monitoring point is less than the safety control reference value. The displacement values of the three monitoring points in the tunnel under 1.5m×1.5m operating conditions, namely, the arch roof, the side wall and the arch bottom, exceed the prescribed threshold and are in an unsafe state. Numerical simulation results show that when the bolt spacing is larger than 1.0m×1.0m, the stress on the surrounding rock and lining is obvious, and the displacement around the hole is also continuously changing. However, when the anchor spacing is less than 1m×0.75 m, the stress on the lining and arch frame is basically unchanged. The displacement around the hole also tends to be stable. Based on the concept of surrounding rock deformation control and flexible support, considering economy, 1.0m×1.0m^1.0m×0.75m is the optimal interval.

关 键 词：大断面隧道 室内模型试验 数值模拟 锚杆间距 围岩位移 

分 类 号：U451[建筑科学—桥梁与隧道工程]