Research on Hard Rock Excavation Fracturing Technology Based on Static Blasting

Static blasting technology can be used for weakening and fracturing of underground coal and rock mass. Compared with explosive blasting, it has the advantages of safety, no vibration and no pollution. In order to explore the cracking effect of hard rock weakening and practical engineering application technology of static blasting, through laboratory tests, numerical simulation and field tests, the expansion mechanical parameters of static crushing agent, the crack evolution law and failure range of static crushing agent on specimens under different aperture and hole spacing, and the selection of field hole layout parameters were studied. The results show that the maximum expansion pressure of the static crushing agent can reach 75 MPa, and the reaction process is divided into three stages, initial stage, rapid reaction stage and subsequent slow reaction stage. The crack development direction of the specimen is along the direction of the minimum resistance line, and the crack expansion shape is mostly ‘Y’ shaped. In acoustic emission detection, the cumulative energy increases step by step, and its peak value decreases with the increase of broken hole diameter. The effect of rock breaking and fracturing is better when the pore size of the crushing hole is controlled at 40~50 mm and the row spacing is controlled at 300~500 mm. The research results confirm the feasibility of static blasting scheme for weakening and fracturing of rock strata, which has certain reference value for practical application.