Influence of the interval between holes on crack propagation in slit charge blasting

Abstract

The influence of different intervals between holes of explosive load on the crack propagation was investigated through the dynamic caustics test and numerical simulation. With the increasing of the intervals between holes, the explosive cracks show no direct penetration any more, rather the deflection of cracks occurs in a "hand in hand" shape. With the increasing of the intervals between holes, the cracks propagation oscillates in the process of expansion and the oscillation is more notable in the area that cracks meet. The peak values of the propagation velocity of main cracks, the stress intensity factor and the stress at the area of cracks meeting all depend on the interval between holes. If the interval between holes is smaller, the peak values is larger, which is beneficial to the directional fracturing.