Optimization Study of Pre-Splitting Hole Spacing for Continuous Charging Based on RHT Constitutive Model

In order to solve the problem of poor overall blasting effect when using pre-splitting blasting technology in Beiya gold mine, based on RHT damage constitutive model, numerical simulation research on pre-splitting blasting under different hole spacings was carried out by using ANSYS/LS-DYNA numerical simulation software. The results show that when the hole spacing of pre-splitting hole is set to 120 cm, the crack between holes has obvious bifurcation and the crack propagation range is large. When the hole spacing is set to 130 cm, the crack propagation range decreases within the surrounding area, and the rock damage around the blast hole is obviously reduced. When the hole spacing is further increased to 140 cm, it is found that the cracks on the connecting line of adjacent pre-splitting holes are only locally connected and cannot penetrate through holes. It shows that the 130 cm hole spacing has reached an ideal balance between reducing the disturbance of the pre-splitting blasting itself to the rock mass and achieving effective blasting. Based on the results of numerical simulation, the site test has achieved good blasting effect. The research results can provide reference for the design and construction of pre-splitting blasting in similar mines.