Research on Rational Width of Chain Coal-pillar in Large Mining Height Workface Recovery Roadway of Shallow Coal Seam

For studying the problem of rational width of chain coal-pillar in large mining height working face recovery roadway of shallow coal seam, taking the recovery roadway of 5103 working face in Heshan Mine as research object, through theoretical calculation and numerical simulation, rational width of chain coal-pillar is 25 m. The roof and floor and two-side deformation are both 35 mm through engineering practice, and its feasibility is demonstrated.