Elastic visco-plastic modelling of one-dimensional consolidation

This papper incorporates an elastic visco-plastic (EVP) constitutive model into the consolidation equation to calculate settlements and excess pore water pressures in clays under multi-stage constant vertical loads in one-dimensional vertical straining. A finite difference method is used to solve the resulting non-linear differential consolidation equation. Results from the model are compared with test data and results from other models. The EVP model is also used to simulate consolidation in different thicknesses of clay to investigate the influence of the thickness on total settlements, dissipation of pore water pressures, strains and stresses. Consolidation analysis using the model can describe phenomena caused by the viscous nature of clays: excess pore water pressures can become larger than their initial values immediately after loading, effective stresses in the clay may become smaller than their initial values, and the relationship between strains and effective stresses at the end of primary consolidation is not unique, but depends on the thickness of the clay layer.