Abstract:
The shaft is a key project, including the mining of shaft engineering minerals and the development and utilization of underground space. As the lower part of the proposed shaft has the advantage of a production system, the use of gravity slag removal is one of the important directions for the development of large-diameter shaft drilling technology. Aiming at the problems such as discontinuous slag discharge, low efficiency, and difficult to cooperate with the rock breaking process, the bucket type slag discharge technology exists. It is necessary to explore how to change the slag discharge mode of the working face during shaft sinking. The gravity slag removal process can improve the efficiency of shaft sinking, that is, through the pre establishment of a small diameter pilot shaft connecting the upper and lower levels of the proposed shaft, or when the upper horizontal construction conditions are not available, the pilot shaft can be directly drilled upward horizontally under the shaft. Under the action of gravity, the crushed rock slag will fall directly to the lower level and then be transported and discharged by loading equipment. Firstly, the applicability and limitation of the slag removal technology with positive and reverse fluid circulation in mechanical rock breaking drilling are discussed. Based on the weight of rock slag, the process of gravity slag removal is proposed. The development status of mechanical rock breaking and gravity slag removal technologies such as large-diameter shaft raise drilling, direct upward raise drilling and pilot shaft boringare analyzed.The problems faced by mechanical rock breaking drilling technology based on gravity slag removal at this stage, such as efficient crushing, stable and reliable drilling tools, controllable drilling deflection, and intelligent drilling, are summarized. The technical processes and equipment of pilot hole drilling, pilot shaft drilling, drilling and blasting expansion, raise shaft drilling expansion, raise shaft drill expansion and shaft boring machine expansion are systematically sorted out. A comprehensive well completion process system with different process combinations has been established. Mechanical rock breaking shaft sinking technology based on gravity slagging will continue to play an important role in the construction of large-diameter shafts in coal mines, metal mines, hydropower, transportation and other fields, and provide reference and reference for the technical development of unmanned, mechanized and intelligent shaft construction.