A DEM approach to study desiccation processes in slurry soils
A new DEM-based approach is proposed to study the desiccation of slurry soils. Distinctly to existing DEM approaches that only consider the solid phase, the proposed method explicitly models both phases, soil and water, using spherical particles to account for their volumetric portions. This new concept allows a close description of slurry soils mimicking actual experiment conditions and providing the capability of simulating suspended soil particles in water including their transformation to the semi-solid state as water evaporates during drying. Furthermore, the water loss can be now explicitly simulated by shrinking water particles, while the solid phase particles remain unchanged. To model the soil-water interaction during drying, an existing liquid bridge force model commonly used in DEM to deal with unsaturated soils is modified to extend its working range to tackle problems involving high water contents. The proposed approach is applied to simulate a desiccation experiment conducted on a Kaolin NY specimen. The results show that the new approach can qualitatively capture main factors controlling the formation and development of the soil curling behaviour observed in this experiment. This study suggests that the new approach can be a promising computational tool to provide insights into the transition behaviour of soils from the slurry to semi-solid states involving saturated and unsaturated soil conditions.
Keywords: Desiccation, DEM, Water particle, Water evaporation, Soil curling