The current study adopts a micromechanical approach to explore the nature of stress transmission in wet granular materials. First, we derive the discrete form of the capillary stress tensor obtained from homogenization to show the virial nature of capillarity through the application of point -wise capillary forces in Discrete Element Modeling (DEM). Furthermore, the non -spherical character of the capillary stress tensor is highlighted through a series of DEM triaxial simulations. Contrary to common thinking, the capillary stress tensor has indeed both mean and deviatoric components due to the underlying micromechanical aspects. Relevant key dimensionless parameters are identified to evaluate the relative magnitude of the capillary stress to the externally applied and contact (intergranular) stresses, thus determining the specific conditions under which the contribution of the deviatoric part becomes considerable. In addition, a DEM simulation of a simple shear test is performed to confirm the anisotropy (non -sphericity) of capillary stress tensor. Finally, the effective nature of the contact stress in the sense of Terzaghi for the constitutive behavior of wet granular materials is investigated via a DEM stress probing analysis. Results suggest that a single contact stress variable - germane to an effective stress - cannot relate to strain for the constitutive law in triphasic condition.
