Micromechanical modelling of the mechanical properties of a granite under dynamic uniaxial compressive loads

A micromechanics-based model is used to study the mechanical properties of a granite under dynamic uniaxial compressive loads. The model is based on interacting sliding cracks uniformly distributed ill the rock material. A dynamic crack growth criterion, which is related to clack growth velocity and dynamic fracture toughness of the rock material? is employed in the analysis. Under dynamic loads at strain rates from 10(-4) to 10(0) s(-1) the crack growth velocity is small compared to the critical crack growth velocity and the effect can be ignored. The strengths of the granite obtained by micromechanical modelling agree with the experimental results. A constitutive relation of the granite is derived from the energy equilibrium equation and correlated with the experimental results. (C) 2000 Elsevier Science Ltd. All rights reserved.