Self-weight sedimentation and consolidation of slurries are common phenomena in natural and geotechnical systems, including dredging and land reclamation projects. As the coupled nature of suspension settling and sediment bed consolidation, predicting sediment evolution is challenging. To address this complexity, this study presents a modified Eulerian two-phase flow model derived from Navier-Stokes equations and systematic experiments to establish unified constitutive relationships across different physical states. Particle-fluid interaction forces in both suspension and solid sediment bed regimes were quantified through settling and permeability tests, incorporating gel point continuity constraints. Sediment bed's compressibility was determined using solid concentration-effective stress relationship obtained from oedometer testing. The proposed model demonstrated good agreement with full sedimentation-consolidation experiments across various initial concentrations. Simulations revealed two distinct settling behaviors governed by initial concentration relative to the gel point: sub-gel slurries develop supernatant-suspension interfaces controlled by hindered settling, while super-gel systems form supernatant-sediment bed interfaces dominated by consolidation. Initial slurry height influenced self-weight stresses, directly affecting sediment bed concentration profiles and normalized heights. This framework successfully integrates sedimentation-consolidation dynamics, captures spatiotemporal evolution of concentration and stress fields, and enables the quantitative identification of phase regime transitions in multiphase particulate flows.
Xu et al. (Fri,) studied this question.