Résumé
The capillarity is studied in 3D polydisperse granular materials at the local and macroscopic scales. At the local scale, an explicit model of capillary cohesion is proposed. It includes a local behaviour law and a rupture criterion that depend on the characteristics of the grain pair. The model is validated by experiments on reference grain pairs. This model, intentionally simple, is implemented in a numerical code based on a 3D distinct- element algorithm, together with a numerical method for the distribution of water. Successful comparisons between numerical and experimental macroscopic tests approve the approach allowing thus to study the macroscopic behaviour of wet granular materials. Finally, the inuence of some couplings is also accounted for in order to show the sensitivity of the capillary cohesion to environmental conditions and to illustrate the potential applications of the code.