Evolution of blast-induced rock damage and fragmentation prediction

A detailed understanding of blasting induced rock damage and fragmentation process is important to blasting design and parameter optimization. Due to the complexity of rock property and damage evolution, it is useful to deal with such problems through statistical methods. In this study, according to the critical fracture characteristic and the relationship between crack density and damage variable, a damage evolution equation under statistical damage mechanics network is suggested by considering the effect of loading rate and initial damage in rock. Based on percolation theory and renormalization group method, critical property of rock damage is analyzed. In order to give a quantitative description for the distribution of fragments, a fractal analysis of damage accumulation is made, and a fractal prediction method of fragmentation resulting from rock blasting is presented.