This chapter summarizes the main observations on localized phenomena and proposes numerical tools to characterize localization processes. To deal with interactions occurring between the different phases of porous media, a regularization technique based on the second gradient model has been extended to multiphysic couplings. The chapter describes the regularization methods used to properly model the strain localization process. It presents the description of the coupled second gradient model in saturated conditions. A biaxial compression test is modeled in order to show the ability of the second gradient model to correctly represent the post‐peak behavior. The second gradient model is extended to unsaturated conditions. The coupled local second gradient model is developed for enriched continua including microstructure effects. The example of a gallery excavation is proposed to evidence the influence of hydromechanical couplings in saturated and unsaturated conditions on the strain localization process.