Experimental study on morphological characteristics of blasting-induced cracks under action of different media

In order to study the influence of different medium on the morphological characteristics of blasting-induced cracks, the blasting tests of plexiglass under the action of air, water, air-suspendedparticles and water-suspended particles were carried out respectively. The length, width and spatial deflection angle of blasting-induced cracks were analyzed. The morphological characteristics of blasting-induced cracks and the distribution of suspended particles in the cracks under the action of different medium were obtained. The experimental results show that when water is used as the medium, the length and width of the main crack are significantly larger than that when air is used as medium, which is increased by 16.9% and 33.3% respectively. When pure air and water are used as the medium, the addition of suspended particles increases the length of the main crack by 45.2% and 45.0% respectively and the main crack width increases by 133.3%and 100% respectively. Under the expansion of the explosive gas, the suspended sand particles are brought into the blasting-induced cracks by the airflow, supporting the crack well and increasing the width of the crack. Moreover, the existence of suspended sand particles weakens the deflection of crack propagation, reducing the distribution range of crack deflection angle by 81.3% and 30% respectively.The experiment conclusion has a certain theoretical guiding significance for enhancing gas extraction technology by blasting.