Influence of air-decoupling charge on rock blasting

In order to investigate the influence of decoupling charge structure on rock blasting, explosion experiments were carried out in the laboratory with cement mortar models and air-decoupling charge with different diameters. The sizes of blasting fragments were screened and the explosive strain was statistically analyzed. Different charge structures were used to numerically simulate the forming process of the cracks and crushing circles during the propagation of explosive stress wave. Experimental results indicate that, compared with coupling charge, air-decoupling charge structure could improve the distribution of fragment size and increase the utilization ratio of explosive energy. Numerical simulation also illustrates that the gap between charge and the wall of borehole could change the stress wave loading rate on the wall, prolong the action time of stress wave and gas, decrease obviously the thickness of crush zone, and lead to the improvement of blasting effect.