Development of two- and three-dimensional continuum-based heterogeneous models for hard brittle rocks

The failure process of brittle rocks under compression involves the initiation and propagation of fractures at the grain scale before their complete failure. This process is influenced by the presence of grain-scale heterogeneities, such as mineral grains of various shapes and properties. To achieve a realistic simulation of this failure process, it is necessary to explicitly simulate grain-scale heterogeneities (e.g., grains and grain boundaries) in numerical models. A common approach involves dividing the numerical model into randomly generated polygonal blocks representing mineral grains. The numerical software programs based on discontinuum methods are more common for such simulations than conventional continuum methods, as they offer a more accurate representation of the brittle rock failure process, including fracture initiation and opening. However, their higher computational costs (long runtime) often constrain their practical applicability. Therefore, research is needed to develop an alternative and more practical approach to simulate the brittle rock failure process using continuum methods. The proposed research aims to develop a continuum-based heterogeneous rock model to replicate the brittle rock failure process. For this purpose, the two-dimensional (2D) and three-dimensional (3D) finite element programs RS2 and RS3 developed by Rocscience will be employed. The objectives of this research are to: a) develop a 2D continuum-based heterogeneous rock model comprising multiple mineral grain types of various properties; b) establish a methodology to simulate core drilling and associated damage using the 2D heterogeneous model; c) develop the first 3D continuum-based heterogeneous rock model; d) investigate the influence of borehole orientation and drilling depth on core damage using the 3D heterogeneous model. It is anticipated that the simulation tools and methodologies developed as part of this partnership will be implemented into future versions of Rocscience's software programs, thereby becoming available to end users worldwide. Furthermore, the outcomes of this partnership are expected to have a significant impact on the next generation of civil and mining engineers in Canada.