Modeling non-ideal velocity of detonation in rock blasting

Abstract

The performance of commercial explosives is an important subject in rock blasting modeling and simulation. As a result of its non-ideal behavior, these explosives usually react below their ideal detonation velocity. In these cases, the multi-dimensional effects, heterogeneities and confinement conditions become important for properly quantifying the detonation state. In this sense, an engineering approach to model twodimensional steady non-ideal detonations for cylindrical stick explosives is used to quantify the expected detonation velocity for given reaction rate parameters and confinement conditions. Founded on an ellipsoidal shock shape approach (ESSA), the proposed model combines the quasi-one-dimensional theory for the axial solution with the unconfined sonic post-flow conditions at the edge of the explosive. A mechanistic confinement approach is coupled with the ESSA model to estimate the effect of the inert confiner on the detonation flow. Finally, the proposed model is used to estimate the expected detonation velocity of two typical commercial explosives in a number of different confinement conditions.