The effects of dynamic pressure on the stability of prepared drifts near the working surface areas

Abstract

Due to the effects of dynamic pressure, the stress distribution of rock mass is very complex. The reason for this could be a risk of stability loss for an auxiliary tunnel system constructed within the study area. In this article by using Flac3D software the author simulated two adjacent working faces with the thickness of 5 m natural coal pillar. Three factors: the upper working face excavation process, auxiliary tunnel mining process, and the location of lower working face, affected by deformation, stress distribution, safety of lower floor area and surrounding rock mass of tunnel. The research results show that during the excavation, the mechanical behavior of the rock mass surrounding the auxiliary tunnel showed displacements, volatility, and phase characteristic. The displacement on the auxiliary tunnel boundary in both excavation and working face cases showed that the roof and the left side wall displacement was greater than the right side wall and the bottom. Therefore, the distance between the auxiliary tunnel and the empty mining space needs to be computed to meet technical and economic requirements.