Disturbance Effect of Blasting Stress Wave on Crack of Rock Mass in Water-Coupled Blasting: Fid-Bau Portal

Disturbance Effect of Blasting Stress Wave on Crack of Rock Mass in Water-Coupled Blasting

Li, Tong / Chen, Ming / Wei, Dong / Lu, Wenbo / Yan, Peng

The disturbance of a blasting stress wave on rock crack propagation directly affects blasting efficiency. This study aimed to explore the disturbance effect of water-coupled blasting using experimental and theoretical analyses. First, a model of crack instability under a blasting stress wave was analyzed. Next, experiments were conducted to study the characteristics of the blasting stress wave disturbance loads. Finally, blasting disturbances in different coupling media were compared. Following a blasting stress wave, explosive-source-penetrating (ESP) and explosive-source-nonpenetrating (ESNP) cracks underwent tensile failure and compression-shear or tension-shear cracking, respectively. In ESP cracks, the blasting stress wave disturbance load included direct and indirect explosive loads; in ESNP cracks, only the disturbance load was transmitted through rock mass. The differences in the disturbances of blasting with different coupling media were primarily due to the peak explosion pressure of hole wall and the wave-attenuation law in coupling medium. In water-coupled blasting, the disturbance effects transmitted indirectly and directly to the ESP crack tip exceeded those in air-coupled blasting by 1.19 and 3.80 times, respectively. In ESNP cracks, the disturbance effect in water-coupled blasting was equal to or greater than 1.32 times that in air-coupled blasting. The results of this study provide a theoretical basis for improving the design of water-coupled blasting.