Bonded particles models of rock plates with circular cavities in uniaxial and biaxial compression

In this paper, a distinct elements code is used to perform a numerical investigation for the size and stress gradient effects on the fracture initiation and propagation around single or pairs of pre-existing cavities in brittle rock. To investigate the rock fracture around cavities and to assess the potential of the numerical model to simulate this behavior, published laboratory physical model on granite is simulated numerically with a Bonded Particles Model (BPM). The numerical model is presented and the calibration of the BPM micro-parameters is described. Then, the calibrated BPMs are used to investigate the effect of the size of the cavity on the primary, secondary and side wall fracturing, as well as on the fracturing modes. Moreover, BPMs with two circular cavities were used to study the interaction of these holes of the same diameter and to investigate the importance of their relative distance. Finally, the simulated material was studied by biaxial tests on BPMs with a pre-existing hole