Study on reasonable offset of mining roadway under close distance coal seams goaf of rock burst mine

Aiming at the situation that the top coal of the close distance coal seams is goaf and the remaining 30 m coal pillar, taking the 2-1 coal seam and 2-2 coal seam of Hulusu Coal Mine as the research background, the mechanical model of the upper coal goaf and the remaining coal pillar under force is established, the stress distribution state of the strata under the coal pillar in the upper coal section is analyzed, and the reasonable spacing of the stoping roadway under the close distance coal seams goaf is studied. The research shows that the optimal offset distance should be 80 m after the protective layer is fully discharged; from the influence range of the overlying coal pillar, the optimal offset distance is 40-80 m; considering the degree of influence on the upper coal roadway, the optimal offset distance should be greater than 80 m; when the offset distance is 160 m, the lower working face mining has the lowest influence on 21101 return air alley. By combining 4 different angles and calculating the intersection of the influence range, the optimal offset distance of the first working face of 22103 was finally determined to be 80 m.