Current situation and prospect of coal mine rock roadway excavation technology

The roadway is the “blood vessel” of the mine, and its excavation efficiency, technological maturity, and safety directly affect the mining efficiency of the mine. At present, the commonly used excavation methods for coal mine rock roadways in China include blasting excavation, mechanized excavation, and blasting mechanical combined excavation. Blasting excavation is divided into manual drilling and blasting method and hydraulic drill rig drilling and blasting method. Mechanized excavation includes comprehensive excavator excavation and TBM excavation. The blasting and mechanical conbined excavation is mainly aimed at hard rock, weakening the overall strength of the rock mass through ultra-deep hole blasting, and finally using mechanization for excavation. This paper summarizes and analyzes the application examples of coal mine rock roadway excavation. Firstly, it introduces the commonly used drilling equipment for the above three methods, compares and analyzes the advantages and disadvantages of each excavation technology, and then elaborates on the technical difficulties that exist in these types of excavation methods. The manual drilling and blasting method has advantages such as low cost and convenient use, but its disadvantages are very obvious due to its high labor intensity, low rock drilling efficiency, and poor working face environment. Most mines use hydraulic drill rigs for blasting and excavation. Case analysis found that the average circular footage of manual drilling and blasting method and hydraulic drill rig drilling and blasting method is 1.7 m and 2.1 m, respectively. As the cross-sectional area of the roadway increases, the number of blasting holes per unit cross-sectional area of the roadway and the unit consumption of explosives tend to decrease. Mechanical excavation can effectively improve excavation efficiency and save labor, but for rocks with high strength, it can lead to rapid loss of cutting teeth and a high dust rate. In addition, the large turning radius, volume, and cost of TBM limit its use in small and medium-sized mines. The blasting and mechanical combined excavation has great flexibility, but the theoretical research on the spatial morphology and blockage length of blasting cracks under geostress conditions is not deep enough. Finally, this paper elucidates some theoretical and technical issues that need to be addressed in current coal mine rock roadway excavation, as well as the future development trends of rock roadway excavation.