Research on the evolution of the deviatoric stress and control of a gas extraction roadway under mining influence

Aiming at the considerable deformation of the surrounding rock and the difficulty of supporting a roadway affected by the mining of close-distance coal seams, this paper takes the 10607 gas extraction roadway of the Malan Coal Mine as the subject of the study, an analysis of the stress distribution of roadway surrounding rock is conducted using a circular hole problem involving plane strains. Using a mechanical model of the roadway, the formula for the second invariant J 2 of the deviatoric stress is theoretically derived. The deviatoric stress J 2 distribution characteristics of the coal pillar floor and the longwall panel floor are analyzed using the simulation calculation software, and the deviatoric stress J 2 evolution of the surrounding rock of the lower gas extraction roadway during the mining of the upper coal seam longwall panel in the close-distance coal seams is studied. According to the evolution of the deviatoric stress J 2 of the surrounding rock of the gas extraction roadway during the mining, a CFST composite support reinforcement scheme is proposed and applied to the 10607 gas extraction roadway of the Malan Coal Mine.