非金属矿掘进巷道直眼掏槽爆破参数优化研究OA

In view of the problem of poor blasting effect and low excavation efficiency caused by the high strength of siliceous rock in the 860 middle section measure roadway of Leji Barite Ore,based on the theory of cylinder cut blasting,a HJC constitutive rock blasting model and SPH algorithm finite element model are constructed to explore the influence law of hole distribution spacing on groove digging cavity formation,optimize the original blasting scheme,and carry out on-site tests.The results indicate that increasing the radius of the empty hole and decreasing the spacing between the empty hole and the charging hole can strengthen the concentration of tensile stress at the centerline between the charging hole and the empty hole,promoting the formation of cavities;When the spacing of the hole distribution is increased from 100 mm to 250 mm,the diameter of the formed cavity is decreased from 29.7 cm to 20.8 cm,and there is a significant negative correlation between the two.After optimization,the blasting cycle footage is increased to 3.0-3.1 m,the maximum blast hole utilization rate is 93.9%and the throwing distance of the blasting pile is shortened by 10-20 m.This research verifies the theoretical mechanism of the empty hole effect and provides parameter optimization templates for the roadway excavation in high hardness rock strata,which has significant engineering values for improving mining efficiency.