Constitutive modeling of sedimentary argillaceous rocks for deep geological disposal of radioactive waste

Argillaceous rocks are considered ideal host geomaterials for deep geological disposal of radioactive waste due to their low permeability, notable sorption capacity, low diffusion coefficient, limited natural fracturing, and capacity for self-sealing. In line with this objective, substantial efforts have been made in the literature over the past decades to model their behavior numerically. Yet, accurately modeling the hydromechanical behavior of argillaceous rocks remains a significant challenge in geomechanics, highlighting the need for further research. Despite the wide variety of geomaterials in this class, common behavioral features are observed, such as anisotropy, structural degradation, strain localization, creep, heterogeneity, and self-sealing. This study summarizes these common features observed in laboratory and field settings and reviews the developed approaches for modeling each behavioral aspect. The goal is to establish a comprehensive framework for the practical modeling of these geomaterials, specifically aimed at applications in the geological disposal of radioactive waste.