ELASTOPLASTIC CONSOLIDATION AT FINITE STRAIN - PART 2 - FINITE-ELEMENT IMPLEMENTATION AND NUMERICAL EXAMPLES

A mathematical model for finite strain elastoplastic consolidation of fully saturated soil media is implemented into a finite element progra m. The algorithmic treatment of finite strain elastoplasticity for the solid phase is based on multiplicative decomposition and is coupled w ith the algorithm for fluid flow via the Kirchhoff pore water pressure . A two-field mixed finite element formulation is employed in which th e nodal solid displacements and the nodal pore water pressures are cou pled via the linear momentum and mass balance equations. The constitut ive model for the solid phase is represented by modified Cam-Clay theo ry formulated in the Kirchhoff principal stress space, and return mapp ing is carried out in the strain space defined by the invariants of th e elastic logarithmic principal stretches. The constitutive model for fluid flow is represented by a generalized Darcy's law formulated with respect to the current configuration. The finite element model is ful ly amenable to exact linearization. Numerical examples with and withou t finite deformation effects are presented to demonstrate the impact o f geometric nonlinearity on the predicted responses. The paper conclud es with an assessment of the performance of the finite element consoli dation model with respect to accuracy and numerical stability. (C) Els evier Science S.A.