Elastic visco-plastic modelling of one-dimensional consolidation

Abstract

This paper 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. Un modèle de comportement élastique-viscoplastique (EPV) est injecté dans ľéquation de consolidation afin de calculer les tassements et les excès de pression interstitielle dans des argiles soumises à des incréments de chargements verticaux, constants, associés à une déformation verticale unidimensionnelle. La méthode des différences fines est utilisée pour résoudre ľéquation différentielle, non linéaire. Les résultats, obtenus à ľaide de ce modèle, sont comparés à des résultats expérimentaux et à des résultats issus ďautres modèles. Le modèle EPV est aussi utilisé pour simuler la consolidation de différentes épaisseurs dargiles afin de ďeterminer Pinfluence de ľépaisseur sur les tassements totaux, la dissipation des excès de pression interstitielle, les contraintes et les déformations. En utilisant ce modèle, on pent décrire les phénomènes dus &greve; la viscosité des argiles: les pressions interstitielles peuvent revenir à leurs valeurs initiales immédiatement après chargement, les contraintes effectives dans les argiles peuvent devenir inférieures à leurs valeurs initiales et la relation, reliant contraintes effectives et déformations à la fin de la consolidation primaire, nest pas unique mais dépend aussi de ľépaisseur de la couche ďargile.

Secondary Compression Features of Jiangsu Soft Marine Clay

“…Therefore, design of earth structures over soft ground requires the consideration of the effects of secondary compression. How to estimate the secondary compression settlement is a geotechnical research area with a long history (Bjerrum, 1967;Berre and Iversen, 1972;Leroueil et al, 1985;Mesri et al, 1997;Mesri and Vadhanabhuti, 2005;Yin & Graham, 1994, 1996Yin, 1999).…”

Characterization of Seismic Responses in Mexico City Using Hilbert-Huang Transform

“…The adjustments expected in selected values of f n , from 1980 to 2020, can be appreciated in Figure 5. What can be anticipated, as the evolution of this phenomenon, is that after the initial reference year the parameter decreases monotonically as the times span increases [27].…”

A mathematical function to represent S-shaped relationships for geotechnical applications

“…For stable creep behaviour, the relationship between the strain å and time t is usually S-shaped (e.g, Berre and Iversen, 1972;Yin and Graham, 1996). The data of one-dimensional compression tests on Drammen clay from Berre and Iversen (1972) are quoted here (Figure 4).…”