Deep Hole Grouting Reinforcement Technology in Working Face of Soft Coal Seam with Large Mining Height

According to loose and broken coal, development of joint fractures, easy rib spalling and roof fall in coal wall in the large mining height work face in Changping Coal Mine. Using field test method, we study the reasonable grouting time, reasonable grouting pressure, sealing hole and plugging method of working face in Changping Mine experimentally, and carry out statistical analysis of rib spalling in working face. The experiment results show that the reasonable grouting reinforcement area of the working face is at the rear of the elastic strengthening stage of advanced supporting pressure. The reasonable grouting area of the large working face is 30 m to 40 m in front of the working face, and the reasonable grouting pressure is 10 MPa to 12 MPa. The rib spalling of the high working face is effectively controlled by the deep hole grouting and the safe production of the working face is ensured.