Experiment on blasting damage and dynamic caustics of jointed medium

Laboratory experiments were performed using a digital laser dynamic caustics experimental system to study the blasting damage effect of joints on medium. The distance between the joint and the borehole was the only variable in this experiment. Research showed that: It is found that the ability of cracks to propagate through a joint is significantly affected by the angle of the crack. When the angle between the crack and the joint increases to 25.1°, the crack cannot pass through the joint. The increase in the distance between the joint and the borehole can reduce the damage caused to the medium. When the distance between the joint and the borehole is 60 mm, the joint does not show significant effect on the dynamic crack propagation. The joint promotes the damage of the medium between the borehole and the joint and inhibits the damage of the medium beyond the joint. With an increase in the distance between the joint and the borehole, the reflected stress wave gradually weakens, and the influence of reflected stress wave on v and K_I^d gradually decreases.