Study on the Surrounding Rock Deformation Laws of Facing-Mining Roadway and the Reasonable Space–Time Relationship of Hydraulic Fracturing

Abstract

The mining confrontation caused by a super-long working face is an important factor that leads to difficulties in the control of surrounding rock in facing-mining roadways. To address this issue, this study takes the 18106 working face of Xiegou Coal Mine as the engineering background. First, deformation characteristics of the surrounding rock in two stages of roadway mining are explored, and the principle of determining the time for fracturing construction is presented. Additionally, the influence of fracturing space position on the control effect of the roadway’s surrounding rock is examined. Results show that the roadway which is influenced by adjacent working face mining has obvious asymmetric deformation, and the order of deformation is as follows: pillar side > roof > coal side > floor. The roof activity in goaf is the key factor of roadway deformation, and the proportion of deformation is 60%, followed by the influence of advance stress, accounting for 38%. After fracturing, with the increase in fracturing height, the deformation of the surrounding rock decreases, and the decrease in deformation of the roof and two sides also reduces, while the decrease in deformation of the floor remains relatively stable. The reasonable fracturing height is 10 m, and the reasonable fracturing construction time is 17 days before the confrontation between the working face and the roadway. Field practice suggests that there are effective cracks in the roof after fracturing, and the deformation of the surrounding rock in facing-mining roadways is reduced by more than 60% compared to that without fracturing. Hydraulic fracturing is significant for controlling the deformation of the surrounding rock in facing-mining roadways.