This paper on "Numerical Modelling of the Hydro-Mechanical Behaviour of Unsaturated Porous Media" was presented at the NAFEMS World Congress on Design, Simulation & Optimisation: Reliability & Applicability of Computational Methods - 9-11 April 1997, Stuttgart, Germany.

Summary

A numerical simulation of the hydro-mechanical behaviour of an unsaturated porous medium is presented. The coupled hydro-mechanical model is based on the continuum theory of mixtures and treats the unsaturated soil as a three phase porous medium (solid, liquid and gas). Principal variables are the solid deformation, the liquid pressure and the gas pressure. The two fluid phases are in motion and a nonlinear pore pressure - saturation relation is used. The resulting system of equations has been discretized in space using the finite element technique and in time by the Θ - method. The comparison between numerical results and experimental test data shows that this hydro-mechanical model is capable to reproduce quantitatively the principal phenomenon in the case of a hydric solicitation. Furthermore, the three phase model is compared to a simplified version considering only a two phase medium with static air phase in order to show the necessity of the first approach.