Application of a damage model for rock fragmentation to the millisecond blasting for ditching deep blast-holes

A modified elastic-plastic model yielded good agreement between the calculated fragmented regions and excavated ditch profiles for blasting in limestone. The numerical simulation was conducted using millisecond delays on a ditching program using deep blast-holes. Both rock movement during ditching and the mechanism of millisecond blasting were analyzed. The results show that the numerical simulation based on the chosen damage model can predict the dynamic event of rock fragmentation and should prove to be useful in blasting design.