浅埋连拱隧道施工过程的力学分析  

Mechanical analysis on construction procedure of shallow multi-arch highway tunnel

作　　者：刘彤[1] 刘新东[1] 

机构地区：[1]西安建筑科技大学理学院,陕西西安710055

出　　处：《四川建筑科学研究》2009年第1期251-255,共5页Sichuan Building Science

摘　　要：针对软弱围岩双连拱隧道三导洞施工方案的特点,采用有限元方法对其施工过程各阶段围岩与支护体系的力学性状进行了分析,并与实测结果进行对比分析。拱顶沉降和周边收敛明显分为上弧形开挖、核心土开挖两个增长阶段,后施工洞室沉降大于先施工洞室。中墙顶部三角区围岩及中墙底部围岩塑性变形较大,施工中应加强监测。两侧导洞临时支护受力很大,应加强横支撑以确保施工安全。中墙受力始终处于偏压状态,中墙底部承受很大的水平向拉应力,应加强横向配筋或采用扩大基础型式。Based on a practical engineering, considering the characteristics such as shallow, weak surrounding rock,large span, doublearch of the tunnel, the stress and strain of surrounding rocks, support structure and mid-wall were analyzed by FEM for different excavating procedure. The simulation results were compared with in-situ monitoring results. The crown settlement and convergence displacement are divided two obvious increasing stages. Surrounding rock upper and under the mid-wall generate bigger plastic strain and should be strengthened. Temporary support of the pilot bears bigger load and should be reinforced. Bearing bigger horizontal direction tensile stress and uneven load, the bottom of mid - wall must have enough reinforcing steel bar or employ augment foundation. The analysis results provide a scientific basis and technical guidance for the construction optimization of the tunnel constructed by three- pilot excavation method.

关 键 词：浅埋连拱隧道 施工过程 有限元法 

分 类 号：U455[建筑科学—桥梁与隧道工程]