Key Parameters of Surrounding Rock Roof Cutting and Pressure Relief Control in Soft Rock Roof Roadway of Deep Mine Stope and Its Engineering Application

AbstractIn this study, the movement and failure law of working face overburden and the distribution characteristics of mining stress are analyzed using laboratory test and numerical calculation methods to address the problems of large deformation, failure instability, and difficult maintenance of the soft rock roof roadways of deep stope influenced by strong disturbance, the roof gas comprehensive treatment roadway of 17191 (1) working face of Pansan mine of China Huainan Mining Group was considered as the engineering background. The deformation and failure mechanisms of the surrounding rock in soft rock roof roadway are revealed, the surrounding rock control technology of presplitting and roof cutting pressure relief is proposed, and the key parameters of presplitting and roof cutting are systematically studied. According to the results, after mining, the overburden presents the distribution of “upper three zones,” in which the heights of the caving and fracture zones are 7 m and 38 m, respectively, the influence range of lateral mining abutment pressure is 80 m, and the influence height exceeds 42 m. The roadway is located in the same layer as the fracture zone and within the influence range of mining. Under the influence of overburden migration of the working face, the stress field around the roadway, and the mining stress field, the surrounding rock of the roof roadway is significantly damaged, and the floor heave is violent. Based on the stress distribution characteristics of the stope and the deformation mechanism of the roadway, the pressure relief control technology of surrounding rock presplitting roof cutting is proposed. The optimal values of key parameters are determined as the roof cutting height of 49.9 m, the roof cutting angle of 10°, and the blast hole spacing of 10 m. The results of this study have been successfully applied in 17191 (1) working face.