Research on Blasting Parameters of Prism Vertical Cutting

Aiming at the problem of determining the parameters of the corner-column cutting hole network, according to the previous research, the calculation model of the radius of the crushing zone R_p and the radius of the fracture zone R_f under the action of rock blasting is summarized and deduced, the effects of blast stress waves and blast gases on rock fragmentation are quantified, and according to the results of R_p and R_f combined with the effect of distending space, the calculation model of the parameters of the cut hole mesh was constructed. Combined with the actual calculation example on site, The radius of the crushing zone caused by the explosion stress wave is R₁ = 50 mm, the radius of the crack zone is R₂ = 550 mm, the radius of the crushing zone caused by the secondary crushing of the explosive gas is l_c = 16 mm, and the radius of the crack zone is l_g = 420 mm. Since the holes should be located in R_p = 66 mm, R_f = 970 mm combination with the space effect of crushing expansion, the distance between the charging hole L and the empty hole and the distance between the charging holes L₁ must satisfy 66 mm＜L＜L₁＜160 mm. Combined with the actual on-site L = 0. 1 m, L₁ = 0. 15 m. A numerical model is established for the cutting scheme to calculate, the simulation results show that the average crack length in the fissure zone is 1069. 4 mm, compared with R_f = 970 mm, the error is 99. 7 mm, the average length of the crushed cavity in the crushing area is 67. 1 mm, and the error is only 1. 1 mm compared with R_p = 66 mm. The cutting scheme has been carried out for many times on-site roadway excavation experiments. The test results show that the utilization rate of the blasthole can be increased from the original 80% to more than 93%, which verifies the validity of the model.