Caving Technology Under Condition of Igneous Rock Invading in Face

The intrusion of igneous rock leads to the unstable occurrence of 10^# coal seam and the hardening of partial area of the roof. During the extraction of the coal face, the exposure area of the roof was relative large, which posed a significant threat to the safe production of the coal face. In line with the above-mentioned conditions, studying coal face caving technology is launched, research results show that the measure called "roof-cutter strengthen support plus artificial forced caving" must be taken to handle with hard roofs when a fully caving of the roof cannot occur; linear intensity (n_zmc) of intensive props supplemented on the caving line is 5.85 per meter, which can guarantee the safe extraction of the coal face at the stage of initial caving; in order to ensure the cutting-off of the roof, a prop should additionally laid out between the normal props of the caving row, in this case, the column space of the props should decreased from 0.5 m to 0.25 m.