210 life cycle of mine production, while panel roadways, ore passes and other works are only limited to the ore mining stage of the panel. In recent years, shaft engineering and construction technologies, which have evolved from the field of mineral mining, have now been extended to the construction of vertical or inclined shaft projects in fields such as urban underground space development, hydropower, transportation, large-scale scientific experiments and national defense. In accordance with past conventions, shaft sinking by drilling rigs, shaft sinking by artificial ground freezing, and shaft sinking by surface pre-grouting are defined as special shaft sinking methods. However, due to the limitations of rock-breaking tools and equipment capabilities, shaft sinking by drilling was previously only applicable to water-rich soft alluvial strata. Shaft sinking by freezing reduces the temperature of the stratum around the shaft, converting liquid water into solid ice, temporarily improving the overall strength of the stratum and preventing groundwater from flowing into the shaft during excavation, which can be redefined as a physical stratum modification method. Shaft sinking by grouting mainly refers to the surface pre-grouting process, that is, before shaft excavation, cementitious materials are injected into the unfavorable strata traversed by the shaft through boreholes to fill the defective geological structures such as faults, cavities, fractures and voids in the stratum, so as to improve the structural strength of the strata traversed by the shaft and reduce the permeability of the stratum. This method can be redefined as a structural stratum modification method. Thus, the two methods can be collectively referred to as stratum modification methods. Conventional shaft sinking by drill-and-blast adopts a short-bench combined excavation and lining operation process, which involves drilling with umbrella drills, manual charging, rock loading with grab loaders, hoisting with skips, and concrete shaft lining pouring with integral formwork. This method requires a large number of personnel to work in the complex environment inside the shaft, facing safety risks such as collapse, water inrush, gas leakage and equipment accidents, which are prone to cause serious occupational injuries to personnel. Therefore, exploring non-blasting rock-breaking shaft sinking methods has become the development direction of shaft sinking technology. To address the challenges of shaft construction in deep water-rich alluvial strata in central and eastern China, specialized large-diameter shaft drilling rigs have been developed by drawing on the technologies of oil well drilling, and a relatively mature shaft sinking method by drilling has been established, which enables unmanned operation underground. Aiming at the problems of low shaft sinking efficiency, long construction period and high cost caused by high risks of blasting rock breaking, complex processes of rock slag collection and hoisting at the shaft bottom, and mismatched rock breaking-slag removal processes during the shaft sinking of large-diameter shafts by the drill-and-blast method, research on technical equipment and processes of mechanical rock breaking drilling for large-diameter shafts based on gravity-driven slag discharge was carried out. Therefore, the authors analyzed the advantages and challenges of the mechanical rock breaking and gravity-driven slag discharge shaft sinking method, systematically sorted out the existing technical equipment system of mechanical rock breaking and gravity-driven slag discharge drilling, and constructed an integrated shaft construction process combining multiple processes. This research is of great significance for the transformation and innovation of shaft construction towards safety, green development, economy and intelligence.
RkJQdWJsaXNoZXIy MTM0Mzk2