Poromechanical solution for one-dimensional large strain consolidation of modified cam clay soil

TL;DR

This paper develops a comprehensive theoretical model for one-dimensional large strain consolidation of modified Cam Clay soil, incorporating soil variability, overconsolidation, and permeability effects, validated through semi-analytical solutions and finite element simulations.

Contribution

It introduces a novel poroelastoplastic large strain consolidation model based on Lagrangian formulation, accounting for soil variability and overconsolidation effects.

Findings

Model accurately predicts large strain consolidation behavior.

Parametric analysis reveals effects of overconsolidation ratio and permeability.

Semi-analytical solutions agree with finite element results.

Abstract

A theoretical model describing the one-dimensional large strain consolidation of the modified Cam Clay soil is presented in this paper. The model is based on the Lagrangian formulation, and is capable of featuring the variability of soil compressibility (inherently so due to the direct incorporation of the specific Cam Clay plasticity model) and permeability, as well as the impact of overconsolidation ratio. The derivation starts from the establishment of the incremental stress-strain relations for both purely elastic and elastoplastic deformations under one-dimensional compression condition, and thereafter the coefficients of compressibility/volume change that are essential to the consolidation analysis. The governing partial differential equation is then neatly deduced in conjunction with the continuity and equilibrium conditions for the soil, with the vertical effective stress being the privileged unknown to be solved for. Subsequently, semi-analytical solution to the developed rigorous poroelastoplastic large strain consolidation model is obtained and verified with the ABAQUS finite element numerical results. Parametric analyses are finally provided to investigate in detail the influences of the soil overconsolidation ratio, large strain configuration, and the variability of the soil permeability on the calculated one-dimensional consolidation response.