Reused roadway failure mechanism and control strategies: a case study of the Shuangliu Coal Mine, China

To solve the problems of surrounding rock large deformation and support difficulties caused by two strong dynamic pressure disturbances of working face mining in reused roadway, this study took the 33(4)18 reused roadway of the Shuangliu Coal Mine (China) as a case study. Physical similarity model experiments, numerical simulation, and theoretical analysis were used to comprehensively analyze the evolution law of field of surrounding rock stress and displacement. The distribution law of abutment pressure during upper working face mining was established, and the formula of advance abutment pressure during following working face mining was derived. The deformation and failure mechanism of reused roadways was revealed from the perspective of the influence of principal stress difference on the development form of the plastic zone, combined with the Mohr-Coulomb strength theory, and a surrounding rock control scheme with ACC as the main supporting component was proposed. The results show that repeated cyclic loading and unloading fail to form a closed stress path, resulting in irreversible structural damage, including tensile damage of shallow surrounding rock and shear damage of deep surrounding rock. Uncontrollable residual deformation of surrounding rock at post-peak strength occurs in the subsequent loading process. The proposed support scheme effectively controls the mutual slip of fractured rock mass in shallow surrounding rock and greatly improves the roadway stability. The results provide theoretical and practical support for the research and engineering application of roadway support in similar working conditions.