This paper on "Modelling of Rock Breaking by Explosives" was presented at the NAFEMS World Congress on Design, Simulation & Optimisation: Reliability & Applicability of Computational Methods - 9-11 April 1997, Stuttgart, Germany.

Summary

Most of the world's mining and quarrying is performed by blasting rock with explosives. Experimental evidence indicates that a large percentage of the crack development and subsequent fragmentation and heave in the blasting process is due to the effects of the high pressure gas generated by the explosive in the blasthole. An explicit discrete element code (ELFEN) has been utilised to dynamically model stress field development, crack generation and growth as well as the motion and stacking of the rock fragments. Rock fracturing is due to both the initial stress wave arising from the blasthole loading and the subsequent gas flow which is treated by coupling the discrete element porosity field to a finite volume gas flow model to form the mechanistic blast model, MBM²D. Several examples are discussed which show striking qualitative differences between blasting with stemming to contain the gases in the blastholes, and without stemming.