SURROUNDING ROCK STABILITY ANALYSIS OF HIGHWAY TUNNEL CROSSING IRON MINE GOAF

The infrastructure construction in China has been increasing in recent years and the working conditions encountered in the construction of line projects are becoming more and more complex. Mine goaf is a common problem in highway construction. When the highway tunnel project passes through the goaf, it will disturb the rock stratum in the goaf, which may cause the deformation and collapse of the surrounding rock, and hence influence the safety of the tunnel construction and the quality of the project. To address this problem, the Yudushan tunnel of Yan-Chong highway is studied in this paper. The existing condition of the goaf in the mined area was investigated with geophysical prospecting method of High-density Resistivity Method. The influence of the goaf on the construction of Yudushan tunnel of the Yan-Chong highway was studied with numerical simulation software. The results show that mining has a certain degree of disturbance to surrounding rock mass, but the overall stability of surrounding rock can basically be guaranteed. But when the tunnel is excavated to the goaf area, it will cause great disturbance to the surrounding rock, which may cause larger ground settlement. Therefore, it is necessary to adopt early grouting method to reinforce goaf and reduce surrounding rock deformation.