Blasting used for rock excavations induces damage in two stages. First, they generate compression and tension waves, which cause the medium to break. Next, a large volume of gases expands, amplifying the fragmentation of the material and displacing the rock. To estimate the fracturing and the fragmented zone, an analysis based on the discrete element method (DEM) is presented. The rocky medium is represented by a set of circular particles joined together by a bonded contact model. The blasting is simulated with a particle expansion algorithm.
Through simulations, it is concluded that the results of the DEM are comparable with those of analytical criteria of rock damage and the models can reproduce the different behavior of the detonation when the pressure-time curve of the explosive changes. In addition, it is observed that the efficiency of the explosive is affected by the rock confinement, the distance between blastholes, and the detonation sequence in a drilling pattern.
