大断面公路隧道开挖工法适应性研究

Research on the feasibility of excavation method of highway tunnel with large section

文章结合成都天府国际机场高速公路龙泉山隧道工程,研究多线并行大断面隧道群的工法适应性。采用数值分析的手段,分别针对2车道隧道与3车道隧道两种工况,考察全断面法、台阶法、双侧壁导坑法等6种开挖工法的应用情况,通过围岩塑性区、围岩变形情况与初期支护结构受力特征等指标计算结果的横向对比,分析不同工法的应用特点,提出不同工况下开挖工法的选择建议。

In this paper,the feasibility of excavation method of multi-line parallel tunnels with large sections is studied for Longquanshan Tunnel Project of the Chengdu Tianfu International Airport Expressway.By means of numerical analysis,the application of six kinds of excavation methods,such as full face excavation method,bench cut method,two side-wall pilot tunnel method,is investigated respectively for two lane tunnel and three lane tunnel.According to the comparison of the calculation results of the plastic zone of surrounding rock,the deformation of surrounding rock and the stress characteristics of initial support structure,the application characteristics of different excavation methods are analyzed,and the selection suggestion of excavation methods under different construction conditions is put forward.