DEM Simulation of Frozen Granular Soils with High Ice Content

High volumetric ice content is one of the structural features of alpine permafrost. The mechanical properties of pure ice are very different from those of dry soil and as a consequence the mechanical properties of frozen soil are highly dependent on the ice content, as highlighted by triaxial experiments available in the literature. On the basis of existing data from experiments under different stress paths (axis-symmetric compression and extension), this paper presents a frozen soil model by using the particle-based discrete element method (DEM). In the model two groups of elements are used for representing soil particles and ice, and two separate sets of micromechanical parameters are calibrated and assigned to each group. Elements from the two groups are then mixed in different proportions in order to simulate the effect of ice content. A series of triaxial compression simulations are then performed and analysed.