明洞暗作隧道施工过程数值模拟研究

Numerical simulation study on construction process of open tunnel subsurface excavation

针对隧道明洞暗作施工过程中支护结构的受力性状,以某在建隧道为工程依托,用ABAQUS有限元分析软件模拟了隧道台阶法开挖的施工过程,由计算结果可知:软岩隧道台阶法施工时围岩位移变化量随施工步序呈现较大差异性,下台阶施工时的围岩位移量显著高于上台阶;围岩在拱脚和边墙处受力较大,出现局部应力集中,其中最大位移为0.950 mm。因此,软岩隧道开挖时应采取合理的围岩预加固措施,及时施作临时支撑及初期支护,确保洞室围岩开挖的稳定性。

ABAQUS finite element analysis software is used to simulate the construction process of the excavation step of the tunnel. The results show that the tunnel is weakly broken. The displacement and release rate of the deformation of the rock are relatively slow. The displacement release rate of the lower step excavation is obviously faster than that on the step excavation. The surrounding rock has a large force at the arch and the side wall,and the local stress concentrated,with a maximum displacement of 0. 950 mm. Therefore,in the construction process should take the pre-reinforcement measures and the timely implementation of the initial support to ensure that the stability of the excavation of the caverns.