爆破中双线型聚能药包最佳成缝角度

To explore the influences of the opening angle of bilinear shaped charge on the effective utilization rate and energy gathering effect, the boundary equation of effective shaped charge was deduced through the theory of instantaneous detonation hypothesis. The effective utilization ratio of the shaped charge structure blasting with 60°, 65°, 70°, 75°, and 80° shaped charge angles was analyzed using the visual implicit functions of SymPy package based on Python language. Through the physical model tests of single-hole Plexiglas and double-hole cement mortar, the crack formation law of pre-cracked holes with different energy-gathering opening angles was studied. Using the LS-DYNA numerical simulation software, five numerical models with energy-gathered opening angles of 60°, 65°, 70°, 75°, and 80° were established to reveal the penetration process of the bilinear energy-gathered structure charge jet and the stress evolution law of the rock unit on the blast-hole wall with different energy-gathered opening angles. The research results show that the effective utilization ratio of the shaped explosives is the highest when the energy-gathered opening angle is 75°. The pre-split hole formation effect when the opening angle of the energy-concentrating groove of the shaped charge is 75° is better than that when the opening angle is 60°, and the stress concentration effect and penetration depth along the direction of the energy-concentrating groove are the best, and the rock unit on the blast-hole wall reaches the peak stress first. The pre-split blasting field tests of two lithologies of Slate and Dolomite were carried out for the double-line shaped energy-concentrated structure charge with the energy-gathering opening angle of 75°. In two different lithologies of Slate and Dolomite, under the condition that hole spacing was increased by 20%, the double-linear pre-split blasting effect of the shaped energy is better than that of the conventional pre-split blasting.