Damage evaluation of rock blasting based on multi-fractal study

Abstract

This study shows the failure mechanism of rock under blasting loads by CT scanning and utilizing fine sandstone as a test specimen. The results indicated that the 3D reconstruction technique can be employed to construct macroscopic fissures in the rock. The complexity of macroscopic fissures in the rock after blasting is quantitatively evaluated using the 3D box-counting dimension. In addition, a multi-fractal method is proposed for comprehensively evaluating macroscopic fissures and microscopic damage of rock after blasting. Compared to the numerical simulation results, the multi-fractal dimension represents the cracks and damage of rock after blasting more precisely than the simple fractal dimension. The blasting experiments of the jointed sandstone demonstrated that the 3D box dimension is suitable for evaluating the 3D macroscopic fractures of the rock after blasting and that it is a straightforward method of macroscopic evaluation. The multi-fractal dimension can evaluate the macroscopic fissures and microscopic damage of various CT scanning rock layers with greater precision.