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 i nteracting sliding cracks uniformly distributed ill the rock material. A dy namic crack growth criterion, which is related to clack growth velocity and dynamic fracture toughness of the rock material? is employed in the analys is. Under dynamic loads at strain rates from 10(-4) to 10(0) s(-1) the crac k growth velocity is small compared to the critical crack growth velocity a nd the effect can be ignored. The strengths of the granite obtained by micr omechanical modelling agree with the experimental results. A constitutive r elation of the granite is derived from the energy equilibrium equation and correlated with the experimental results. (C) 2000 Elsevier Science Ltd. Al l rights reserved.