This paper presents a theoretical framework for approximating the gelling concentration in suspensions, with a focus on its application to the parameterization of soil consolidation processes in coastal sediment environments. The model is based on the integration of principles from rheology, colloid science and sedimentology, and the analysis of the change in rheological viscosity as a function of volumetric sediment concentration. Validation is performed against measured rheological data and shows that the model is able to accurately approximate the gelling concentration of sediment under varying environmental conditions. The model provides valuable insights into the consolidation dynamics of saturated soils in estuaries by linking micro-scale sediment properties and macro-scale geotechnical phenomena. In addition, amore robust constitutive equation for estimating effective stress was developed that accounts for both permeability and effective stress regimes by incorporating the underlying physics of each. The results show that the proposed model closely aligns with the conceptual model of sediment concentration profile, accurately depicting the transition from fluid mud to consolidated bed, and capturing the irregularities and inflection points in sediment concentration that were not represented in previous models.
