In this work, the general ACMEG-TS thermo-elasto-plastic constitutive model for saturat-ed/unsaturated clayey soils has been implemented in the finite element code COMES-GEO for the analysis of non-isothermal saturated/partially saturated deformable porous materials. The numerical model is based on a fully coupled heat and multiphase flow model in de-forming porous media. The porous medium is assumed to be a multiphase system where in-terstitial connected voids of the solid matrix may be filled with liquid water, water vapor and dry air. The general frame of averaging theories has been used in deriving the governing equations. Phase changes of water (evaporation-condensation, adsorption-desorption) and heat transfer through conduction and convection, as well as latent heat transfer are considered. The elasto-plastic behavior of the solid skeleton is assumed homogeneous and isotropic; the effective stress state is limited by the temperature and capillary pressure dependent ACMEG-TS yield surface. The governing equations are discretized in space and time by means of the finite element method. The numerical examples will show applications of the full set of equations. Validation of the implementation of the constitutive model is made by selected comparison between model simulation and experimental results for different combinations of thermo-hydro-mechanical loading paths. The non-isothermal elasto-plastic consolidation of a soil column of Boom clay loaded by thermal, mechanical or environmental conditions is studied, aiming to analyze the effects of the environmental loads on this material candidate for an underground nuclear waste storage facility.
Multi-physics modelling of thermo-elasto-plastic multi-phase porous materials
SANAVIA, LORENZO;LUISON, LORIS;PASSAROTTO, MAREVA;
2012
Abstract
In this work, the general ACMEG-TS thermo-elasto-plastic constitutive model for saturat-ed/unsaturated clayey soils has been implemented in the finite element code COMES-GEO for the analysis of non-isothermal saturated/partially saturated deformable porous materials. The numerical model is based on a fully coupled heat and multiphase flow model in de-forming porous media. The porous medium is assumed to be a multiphase system where in-terstitial connected voids of the solid matrix may be filled with liquid water, water vapor and dry air. The general frame of averaging theories has been used in deriving the governing equations. Phase changes of water (evaporation-condensation, adsorption-desorption) and heat transfer through conduction and convection, as well as latent heat transfer are considered. The elasto-plastic behavior of the solid skeleton is assumed homogeneous and isotropic; the effective stress state is limited by the temperature and capillary pressure dependent ACMEG-TS yield surface. The governing equations are discretized in space and time by means of the finite element method. The numerical examples will show applications of the full set of equations. Validation of the implementation of the constitutive model is made by selected comparison between model simulation and experimental results for different combinations of thermo-hydro-mechanical loading paths. The non-isothermal elasto-plastic consolidation of a soil column of Boom clay loaded by thermal, mechanical or environmental conditions is studied, aiming to analyze the effects of the environmental loads on this material candidate for an underground nuclear waste storage facility.
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