Analysis On Numerical Simulation Of Parallel Tunnel In Different Rocks

The Parallel tunnel is extensively adopted according to its own characteristics. This paper is based on parallel tunnels on Huang-Qu-Nan highway projects. Based on locale investigation, indoor experimentations and numerical simulations, research the factors of clear distance of two holes, depth of burial, off center pressure and middle rock pillar safety. The main accomplishments as follows:1. Set up the 2D finite element models in III,IV level of rocks, analyzing on stress, displacement, plastic zone and plastic energy, considered that when the clear distance is increased from 4m to 6m, the force of rock is improved most remarkable. But it's less effect When the clear distance is increased from 6m to 8m. Researching on the space effect of excavation face, the range of its affection is only belong to the approaching area, when research on the sections which far away from the excavation face, the affection could be ignored.2. Set up the 2D finite element models for typical cases of four Parallel Tunnels on Huang-Qu-Nan highway projects, considered that off center pressure and depth of burial effect compositely and rangability. When the depth of burial beyond 20m, the off center pressure affection could be ignored, When the depth of burial is less than 20m, the off center pressure affection would be more obviously.3. Set up 3D finite element model which based on indoor experiment in V level of rocks to research the safety of Middle Rock Pillar. In this research, the middle rock pillar is partitioned into three parts to reinforcement. The reinforcement of centre part is considered as the most effective method to improve the middle rock pillar safety.