Verification of a laboratory-based dilation model for in situ conditions using continuum models

With respect to constitutive models for continuum modeling applications, the post-yield domain remains the area of greatest uncertainty. Recent studies based on laboratory testing have led to the development of a number of models for brittle rock dilation, which account for both the plastic shear strain and confining stress dependencies of this phenomenon. Although these models are useful in providing an improved understanding of how dilatancy evolves during a compression test, there has been relatively little work performed examining their validity for modeling brittle rock yield in situ. In this study, different constitutive models for rock dilation are reviewed and then tested, in the context of a number of case studies, using a continuum finite-difference approach (FLAC). The uncertainty associated with the modeling of brittle fracture localization is addressed, and the overall ability of mobilized dilation models to replicate in situ deformation measurements and yield patterns is evaluated.