Application of Micromechanical Modeling to Prediction of In-Situ Rock Behavior

With advances in numerical modeling techniques, Voronoi Tessellations are being increasingly used to generate simulated grain structures for investigation of small-scale damage processes in rocks. In a Voronoi model, a material is represented as an aggregate of polygonal blocks that interact through contacting interfaces. Typically, a set of input micro-parameters is calibrated to numerically replicate the macroscopic mechanical behavior of the rock under study. The calibration is mostly restricted to attributes estimated from laboratory testing, such as damage threshold levels, uniaxial compressive strength and tensile strength. While the potential of Voronoi Tessellations in modeling small-scale damage processes has been extensively tested, its utility in capturing field-scale behavior is largely unexplored. This study attempts to bridge the gap through development of a calibrated laboratory scale model of Creighton granite followed by upscaling it to an 8 m wide pillar. An assessment of the Voronoi model's abilities and shortcomings were investigated through a qualitative and quantitative comparison of the model's macroscopic behavior against empirically validated continuum model results recently published by the authors and documented pillar behaviors as seen in the field.