Fractal study of media damage under blasting loading

YANG Renshu; XU Peng

doi:10.13225/j.cnki.jccs.2017.0107

Abstract：Based on the calculation theory of box-counting dimension,a calculation method to calculate the fractal dimension of blast-induced cracks is proposed,and the relationship between fractal dimension and damage degree by blasting is established.A box-counting dimension algorithm based on digital image is compiled using Matlab software.The fractal character of blast-induced cracks under both ordinary charge blasting and slit charge blasting is analyzed using the boxing-counting dimension algorithm,and the damage degree of different regions around borehole is determined.The results show that,in ordinary charge blasting,the damage degree induced by blasting reduced with crack propagation,but almost the same in same regions away from the borehole.In slit charge blasting,the damage degree of blast media presents a significant regional and orientated character,in region Ⅰ,compared to the ordinary charge blasting,the damage degree induced by blasting along the slit direction slightly decreased,which reduced significantly in non-slit direction.In region Ⅱ,the damage degree induced by blasting along the slit direction increased compared to the same region in ordinary charge blasting,while the damage degree decreased in non-slit direction.In region Ⅲ,the damage degree along the slit direction increased significantly,while it decreased in non-slit direction.The calculation of damage degree induced by blasting based on fractal dimension can be used to quantitatively evaluate the spatial distribution characteristics of blast-induced cracks,so as to explore a new way to study the evaluation law of damage degree induced by rock blasting.