Optimization of Pressure-relieving and Danger-breaking Parameters for Stope Large Diameter Borehole

Based on the issues of high degree roadway stress concentration of a colliery in the first mining area and the signs of coal rock outburst danger, taking stress concentration of 1303 working face haulage roadway as research object, we simulate the hole diameters of 50, 75, 108, 120 mm, the pressure relief impact of different drilling depth of 10, 20, 30, 40 m, different borehole spacing of 3, 5, 8 m. The simulation showed that the larger the hole diameter was, the smaller the pressure relief hole spacing was; the more moderate the hole depth was, the better the effect would be. Through comparative analysis and combining the field conditions, the hole of 108 mm diameter, 5 m spacing, 20 m depth was finally recommended as advanced pressure relief drilling parameters. The good results of 1303 working face incolliery were achieved.