The relation between the mode of fragmentation and the stress field parameters in a fractured medium

Conclusions

• 1. In fissured media, the stress field is less intense than in monolithic media and there is a high degree of attenuation of the stresses as we go further from the explosive charge.

• 2. More efficient utilization of the energy stored in the stress field due to the explosion is possible if we can create conditions which hinder the opening-up of fissures and if the rock does not move as a rigid whole.

• 3. Studies based on models revealed that the presence of fissures markedly affects the mode of fragmentation of the models and the stress distribution in the medium due to blasting. The decrease in stress on passage through a fissure is due to refraction at the rock-filler interface and to high inelastic losses in the filler material.