Discrete Element Simulation of Cavity Expansion in Rock

Abstract

Cavity expansion within soil or rock is an important issue in geomechanics because it often appears in geotechnical related problems. This work describes the initiation of fracture in a laboratory specimen of Berea sandstone with a cylindrical opening, modeled using the discrete element method (DEM). The effect of far-field stress and borehole size on breakdown (peak) pressure was investigated. The results demonstrated that an increase in either the far-field stress or the borehole diameter caused the peak pressure to decrease. This showed that the size effect was governed in part by both the loading conditions and borehole size.