Explosion propagation and characteristics of rock damage in decoupled charge blasting based on computed tomography scanning

Blasting in rocks typically causes the remaining rock mass to be subjected to varying degrees of damage and failure, leading to a decline in the mechanical properties and bearing capacity of the surrounding rock. In this study, a decoupled charge blasting experiment for small-charge small-scale red sandstone specimens was conducted in a laboratory; the damaged specimens (after blasting) were scanned and reconstructed using computed tomography (CT) scanning and three-dimensional reconstruction technology. The relationship between the gray scale change characteristics of the CT images and the decoupling coefficient was analyzed. Additionally, the analysis dimensions and damage degree of the damaged specimens (after blasting) were calculated and the damage degree of the indoor small-scale samples (after blasting) was quantitatively evaluated. Furthermore, the relationship between the decoupling coefficient and the blasting action was examined using the LS-DYNA simulation software. The results indicated that the gray-scale value tended to increase with the decoupled coefficient, and the decoupled coefficient demonstrated a significant influence on the blasting action. Thus, the proposed method serves as a suitable means for the evaluation of the failure mechanism through the reconstruction of the spatial distribution of internal cracks.