Multi-field numerical modeling of slurry infiltration in saturated soil

Abstract

Existing numerical methods for modeling slurry infiltration often employ a fluid continuity equation commonly used in groundwater flow analysis. However, it is essential to account for the changes in fluid density and viscosity due to shifts in slurry concentration. In view of this, a multi-field numerical model is developed to simulate the slurry infiltration in saturated soil considering the coupling relationship between particle transportation, fluid seepage, and soil deformation. The governing equations of slurry infiltration are derived based on the mass conservation law. The permeability coefficient is modified through spatiotemporal variation of slurry viscosity, which is governed by concentration modifications. The calculated results are validated using the existing test data, which rectifies the issue of non-conservation of mass in the existing model based on the continuity condition of the liquid phase. Finally, the method is applied to a model of a slurry trench to simulate the process of slurry infiltration, including the spatiotemporal variation of deposition, fluid pressure, and concentration. The time of mud cake formation is determined based on the pressure–time distribution. It is found that the time of mud cake formation in the slurry trench can be shortened by increasing the slurry concentration.