Research on Strata Behavior Laws of “Hilt-shape” Fully Mechanized Working Face with 7 m Large Mining Height

In order to ensure roof safety during the connecting period of short and long faces at “hilt-shape” working face with 7 meters mining height, through the actual measurement of strata behavior laws at 52304 “hilt-shape” fully mechanized working face in initial stage, influenced by the shorter face of 52304-1 mining area, the lower key layer of overlying rock, the larger fracture length, the larger coefficient of direct roof, it presents the mine pressure laws of longer initial pressure step, lower pressure strength at “hilt-shape” working face with 7 meters mining height in initial mining stage, which is in favor of roof control in the connecting area of changing the "hilt" face form from short to long.