Development history and new technology research progress of rock roadway blasting excavation in coal mines in China

Roadways are the arteries of coal production. Based on the construction of rock roadway drilling and blasting method, from the aspects of key blasting technology, tunneling equipment, blasting equipment, etc., the development process of rock roadway blasting in China's coal mines has gone through three stages: blasting quality control, driving speed increase, and roadway safety service guarantee. On the basis of summarizing and analyzing the development characteristics and history of the three stages, the research progress and engineering application of the new technology of rock roadway blasting in coal mines are mainly introduced: ① Peripheral directional fracture control blasting technology controls the distribution of blast energy in the medium, and verifies the effect of shaped charges on improving the quality of roadway profile formation, reducing surrounding rock damage and reducing the number of blast holes. ② In terms of parameter optimization technology for ultra-deep blasting of cutting holes, the ultra-depth is related to the cycle footage and the area of the roadway profile surface, and the ultra-depth value directly affects the utilization rate and unit consumption of the blast hole. For the typical case of Gubei Mine in Huainan, the blasting effect is the best when the over-depth is 400 mm. ③ In terms of segmental charge blasting technology in the hole, the optimal proportion of the upper explosive is 0.382, combined with the digital electronic detonator for segmental detonation, creating a precedent for the use of digital electronic detonator blasting in coal mine roadways. ④ In terms of similar-cut blasting technology, the difference between traditional notch blasting and similar-cut blasting is analyzed theoretically, and the importance of equalized resistance line is proposed and confirmed. The comprehensive application of the above blasting technologies reduces the number of blastholes in full-face blasting from an average level of (5−6) S to (3−4) S (S is the cross-sectional area of the roadway). The effects of increasing single-cycle footage, improving blast hole utilization, controlling roadway profile forming quality, and reducing surrounding rock damage have been achieved. From the perspective of the entire life cycle of the coal mine underground space project, the continuously optimized blasting technology reduces the cyclic dynamic disturbance to the surrounding rock and structure, and ensures the long-term service safety of the coal mine rock roadway project.