Space-time effect of blasting stress wave and blasting gas on rock fracture based on a cavity charge structure

There are still varying opinions on the relative spatio-temporal contributions of blasting stress wave and blasting gas in the theoretical study of rock blasting due to the transient nature of the blasting process and the complexity of the blasting effect. Based on this, the study proposes a cavity charge structure entailing quantitative and differentiated research on the effects of blasting stress wave and blasting gas over time and space. The time and space action characteristics of blasting gas are regulated by changing the charge structure of the borehole and placing a cavity between the charge and borehole wall, and the “double-peak” evolution law of blasting strain is obtained. The first peak is generated by blasting stress wave, and the second peak is generated by blasting gas, with a delay between the first and second peaks. Further analysis shows that the cavity has different effects on blasting stress wave and blasting gas. Finally, the space-time effect of blasting stress wave and blasting gas can be fully utilized to achieve controllable rock fragmentation by adjusting the charge position and the cavity volume in the cavity charge structure.