Holley, Elizabeth A.Walton, GabrielContreras Inga, Carlos Efrain2020-04-062022-02-032020-04-062022-02-032020https://hdl.handle.net/11124/174060Includes bibliographical references.2020 Spring.During the last few decades, many studies have been focused on the understanding of brittle failure mechanisms in hard rocks where the intact rock strength controls the rock mass strength. Discrete element methods have been used to study fracture development processes in intact rocks through laboratory-scale simulations. The simulations represent the grain structure of a rock as an assembly of Voronoi blocks, where each block represents a mineral grain, and a set of parameters that represents the micro-properties of the grains and the contacts between them is calibrated to numerically replicate the macro-mechanical behavior of the rock. Although Voronoi grain assemblies provide reasonable approximations of actual grain structures, the random nature of such assemblies increases the uncertainty of the calibrated contact micro-properties, potentially leading to incorrect estimations of the rock strength. This study investigated whether a more realistic depiction of the grain structure can be used in combination with previously calibrated sets of micro-properties to predict brittle rock mechanical behavior with a reasonable degree of accuracy and minimal micro-property calibration. A series of 3D Voronoi and 2D deterministic models were developed to assess the effects of grain size, shape, and arrangement on the simulated rock strength. The modeling results show that it is possible to predict the strength of a rock with a high degree of accuracy using reasonably simplified representations of the grain structure in Voronoi models. In addition, the results of the comparative analysis can be used as guidelines to simplify the process of representation of grain structures.born digitalmasters thesesengCopyright of the original work is retained by the author.Effect of the representation of grain structure on the prediction of brittle rock mechanical behavior using bonded block modelsText