Modelling of induced anisotropic damage in granites

This paper deals with numerical modelling of induced damage in three granites. A continuous anisotropic damage model is proposed in the framework of thermodynamics and fracture mechanics. A second rank tensor is used to describe damage state which is directly related to orientation and density of microcracks. Both time independent and time dependent (or sub-critical) growth of microcracks are taken into account. A simple procedure for the determination of model parameters from standard laboratory tests is proposed. Comparisons between model simulation and experimental data are presented for some basic loading paths. Finally the application of the model to stability analysis of the Mine-by test tunnel of the URL in Manitoba (Canada) is presented. A comparison between numerical predictions and in situ observations makes it possible to evaluate the performance of the proposed model.

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