Roof Control at General Caving Coal Face in Hard Coal Seam

Through mining practice in the second mining area,at-310 m level,in south No.11 coal seam in Fuli Coal Mine,the reasons for roof unstability at the general caving coal face were analyzed.Aimming at the adverse geological factors with hard roof,it was concluded that the key of success was caving nature of roof coal at the general caving coal face.The theoretical foundation was provided for caving roof coal.Some measures were adopted,such as infusion presplitting with high pressure water,the deep,medium and shallow holes presplitting blasting,increasing the intensity of support.The pressure distance was efficiently reduced. The pressure intensity was mitigated.The large area caving of difficult caving roof in thick coal seam was prevented.The safe production at face was ensured.