Unloading Mechanism and Design Analysis of Surrounding Rock in Deep High Stress Roadway

Abstract

The strong pressure on the roof, excessive concentration of stress, soft and broken surrounding rock, and difficulties in roadway support have always been important factors affecting the safety and stability of deep high stress soft rock roadway. Based on the special space unloading function of the pressure relief groove in the deep soft rock roadway, starting from the unloading pressure theory of deep surrounding rock, this paper has analyzed the effect of the pressure relief groove in relieving the pressure of the deep mine and controlling the deformation of surrounding rock. Three dimensional numerical simulation software FLAC3D was used to compare and analyze the surrounding rock failure and stress distribution characteristics before and after the excavation of the pressure relief groove in the deep high-stress soft rock roadway, and the optimum setting position of the pressure relief groove was also optimized. The results show that the deformation of surrounding rock can be effectively controlled after excavating and unloading pressure trough in deep high-stress soft rock roadway, and the displacement of top and bottom plate and roadway side can be reduced by nearly 30mm; the stress concentration is significantly reduced, the stress peak is transferred to the deep part of surrounding rock, and the pressure relief effect is obvious, which effectively maintains the safety and stability of the roadway, and indicates the direction for the pressure relief adjustment and stress control of the high-stress soft rock roadway at the deep part.