Near-field vibration from blasting and rock damage prediction with a full-field solution

A semi-analytical full-field solution for the radiation of seismic waves has been developed and applied to calculate the near-field vibration from blasting. The shape of the source function applied to the blasthole wall has been obtained from numerical modelling of detonation, with a peak value determined as the shock matching pressure of the detonation products and rock. Particle velocity and acceleration signals from four blasts have been recorded and used for the purpose of determining the quality factors (Q) of the rock mass, expressed as functions of the radial distance to the blasthole. The model consistency has been validated by verifying that the resulting peak particle velocity at the blasthole wall coincides with the particle velocity obtained from the explosive-to-rock shock matching calculation. Fracture zones are identified using a failure criterion based on principal stresses of the resulting Cauchy's stress tensor and uniaxial compressive and tensile strengths. Two variants of the industry-standard Holmberg-Persson approach have been compared with the full-field solution.