Fine characterization and grouting simulation of borehole fracture development in burnt rock

Burnt rock, as a special rock characterized by highly developed internal fractures, provides excellent spatial conditions for the storage of groundwater resources. However, due to the mining disturbance in the working face of the coal seam, the internal fractures of the burnt rock layer will further develop to generate a large number of macroscopic fractures. If these fractures expand to the working face of the coal seam, it will bring safety problems to coal seam mining. Therefore, this study first conducted a detailed identification of borehole fractures in burnt rock, constructed a fracture distribution model, and analyzed the development of fractures in the burnt rock layer. Second, grouting simulations of the burnt rock mass with fractures were performed to examine the stress field distribution of the burnt rock mass under different grouting pressures. It is concluded that for regions with uniformly distributed fractures, a grouting pressure of 2.0 MPa is more effective, while the areas with non-uniformly distributed fractures require a grouting pressure of 2.5 MPa.