Comparison of Micromechanical Elasticity Models for Cemented Soils

Cemented soils have particles held together by a binding agent. Of particular interest are weakly cemented soils found in an intermediate state, between granular and solid, when loading begins to break their bonds. To properly understand and describe such materials, appropriate contact laws are needed. This constitutive behavior has two main parts, elasticity and bond rupture; several works have focused on the bonds’ failure criterion, and fewer have dealt with their elastic response. This work compares granular specimens’ macroscopic elastic behavior based on various contact bond laws employed with the discrete element method (DEM). An advanced bond law proposed and evaluated by one of the authors is compared with the other two simpler laws in formulation but well established in the literature. Cementation is applied to DEM samples with spherical grains in different isotropic states with different densities and contact connectivities. Overall, all laws can capture some fundamental aspects of the samples’ elasticity and its dependence on the bond characteristics (bond geometry, bond stiffness). However, as the bond law becomes more complex, more effects affect the macroscopic elastic response.