According to the specific location conditions of Chinese mines, mineral resources need to enter the mine through the DTH Bit. When the tunnel enters the ore body, the vertical and inclined shafts are constructed from the surface to the required depth. When the excavation reaches the designed mining level, it can drive some Horizontal roads used for transportation, ventilation and pedestrian access to the ore body. According to the distribution characteristics of the ore body, various vertical shafts should be constructed, such as blind shafts or inclined shafts connected with different levels of ore bodies, ore storage ore, ore passing through the mine Substance slips to the collection layer. There is no outlet on the ground of these underground wells. Due to the size of the shaft, the drilling equipment restricts or prohibits supporting facilities in a narrow space. The reverse sinking method using the lifting drilling method is suitable for the lifting drilling method. In underground mining operations, vertical or inclined shafts are produced from bottom to top.
First, drill the small diameter hole of the pilot hole, and the chips fall to the lower layer through the hole. Heightening is a kind of excavation that can be constructed by lifting drilling method. It is also suitable for other underground projects, such as water pipes, air shafts, elevator shafts and cables. During the construction of the project, these excavations are important and difficult parts of the shafts of hydroelectric power stations and pumped storage power stations, highways, railway and subway long tunnels, ventilation shafts and exit channels, as well as underground nuclear waste storage and military facilities.
In the construction process, except for the post-reaming process introduced in the method, the method of pilot hole by boring machine is the same as that of traditional drilling machine. When the pilot hole breaks through to the lower layer, the Drill pipe is removed with a large diameter The reaming head is replaced, and the reamer is rotated and pulled back toward the drilling unit. In this way, a large-diameter shaft is formed. A complete set of boring machine includes a drill, a drill string and an auxiliary system. Unlike traditional drilling machines, during the drilling process, the cuttings will drop to a lower level due to gravity, which is a common feature of all types of drill bits.