额尔齐斯多金属公司别洛乌索夫卡矿,在构筑水力蓄气峒室时发现,有必要扩大充水室与蓄气室之间的放水孔直径。因为水力试验证明,连接孔的放水时间已超过计算值,因此,应将放水孔直经至少要扩大两倍。对大直径深孔凿岩方法的分析表明,在该矿的矿山地质条件下,采用牙轮钻头最适于有效她钻凿裂隙发育,f=15～19的岩体。在现有的地下牙轮钻机中,东方机械制造厂 The Erzurovska Mine of the Irtysh Multimetal Company found that it was necessary to expand the diameter of the drain hole between the water-filled room and the gas-storing room when constructing the water-storing room. Because the hydraulic test proves that the connection hole has been discharged for more than the calculated value, the drain hole should be doubled at least straight. The analysis of large diameter deep hole drilling method shows that the roller cone bit is the most suitable for rock mass with f = 15 ~ 19, which is suitable for drilling the fissure in the mine geological conditions. In the existing underground cone drilling rig, the Oriental Machinery factory