Dilatancy-induced surface deformation in dense cohesive granular media

Using discrete element method simulations, we investigate the behavior of dense cohesive granular materials under shear in a split-bottom cell. When granular materials with interstitial liquid bridges are sheared in a split-bottom cell, a localized shear band develops, accompanied by a surface elevation. Cohesion, governed by the surface tension of the interstitial liquid, enhances dilatancy in dense cohesive packings, leading to expansion within the shear band and the emergence of a surface elevation. This surface deformation is observed not only in cohesive systems with high particle density and large liquid surface tension but also in those with lower values of these parameters. The equivalent Bond number arises as a key control parameter for the surface deformation, shaping both the evolution of the surface profile and the packing density. At higher shear rates, inertial effects dominate dilatancy, resulting in less pronounced surface deformation.