A New Blasting Permeability Enhancement Scheme For Deep-Buried Soft Coal Mining Face Based on Borehole Deformation Characteristics

When blasting to enhance permeability in deep-buried soft coal mining face with a hard roof whose gas drainage requirement is higher, the charging hole and control (which doubles as hole) are easy be deformed damaged, seriously affecting implementation effect. Combining stratum characteristics of seam surrounding rock, idea arranging boreholes near rock reduce deformation, inspired by end effect, put forward. Then, experimental research on deformation at different distances from carried out, results show that closer borehole (floor), smaller under same stress conditions within certain distance. Based this, new scheme holes floor proposed designed. The field test 60 m deep successfully realized remarkable enhancement effect achieved, verifying feasibility effectiveness improved scheme. This study explores practical value reference significance for roof.