On micromechanical damage modeling in geomechanics: influence of numerical integration scheme

in International Journal of Computational & Applied Mathematics (2013), 246

Tunnel excavations in deep rocks provide stress perturbations which initiate diffuse and/or localized damage propagation in the material. This damage phenomenon can lead to significant irreversible ... [more ▼]

Tunnel excavations in deep rocks provide stress perturbations which initiate diffuse and/or localized damage propagation in the material. This damage phenomenon can lead to significant irreversible deformations and changes in rock properties. In this paper, we propose to model such behavior by considering a micromechanically-based damage approach. The resulting micromechanical model, which also accounts for initial stress, is described and assessed through the numerical analysis of a synthetic tunnel drilling in Opalinus Clay. A particular emphasis is put on the numerical integration of the model. In particular, an appropriate choice of the latter is required to ensure the numerical stability and a confident prediction of excavation damaged zone around tunnels. [less ▲]

The role of the Excavated Damaged Zone in HGA field-scale Experiment Modelling

in FORGE Symposium (2013)

A water retention model for compacted clayey soils

in 3rd International Symposium on Computational Geomechanics (ComGeo III) (2013)

A micro–macro approach of permeability evolution in rocks excavation damaged zones

in Computers & Geotechnics (2013), 49

Excavation damaged zone, with significant irreversible deformations and nonnegligible changes in flow and transport properties generally occurs in indurated clay around underground structures. The stress ... [more ▼]

Excavation damaged zone, with significant irreversible deformations and nonnegligible changes in flow and transport properties generally occurs in indurated clay around underground structures. The stress perturbation around the excavation could lead to a significant increase of the permeability physically due to diffuse and/or localized microcracks growth in the material. In the present study, we investigate microcracks-induced damage processes together with the subsequent modification in permeability. The proposed approach is based on a homogenization-based upper bound extended to the context of micro-cracked media in presence of initial stress. Application of this approach is done on a borehole excavation problem related to the Selfrac in situ experiments on Opalinus Clay. Although, the model fails to quan-titatively account for the in situ permeability change (which may also originated from existing macro-fractures), its prediction shows a significant evolution of the material permeability around the borehole. This is in qualitative agreement with available data. [less ▲]

Modèles de comportement thermo-hydromécaniques inclus dans le code aux éléments finis LAGAMINE de l’Université de Liège

Report (2012)

Field scale experiment modelling in Opalinus Clay: the HGA experiment

in Clays in Natural & Engineered Barriers for Radioactive Waste Confinement, 2012 (2012)

Numerical modelling in TIMODAZ: developments and achievements

in Post-TIMODAZ International Workshop THM effects in clay host rocks for radioactive waste repositories (2012)

Approche micro-macro de l’endommagement et des évolutions de perméabilités induites autour d’excavations souterraines dans l’argilite de Mont-Terri

in Transfert 2012 (2012)

Excavation damaged zone and permeability evolution modeling in indurated clays based on a micromechanical approach

Conference (2011)

Modélisation par changement d’échelle de l’endommagement et des évolutions de perméabilité dans l’argilite

in 20ème Congrès Français de Mécanique (2011)

Le creusement d’excavations souterraines dans une roche est à l’origine de la formation d’une zone endommagée, où des microfissures se développent et perturbent fortement les propriétés de transport du ... [more ▼]

Le creusement d’excavations souterraines dans une roche est à l’origine de la formation d’une zone endommagée, où des microfissures se développent et perturbent fortement les propriétés de transport du matériau. L’objectif de cette étude est de représenter ces phénomènes hydromécaniques par une approche micromécanique d’endommagement, couplée aux évolutions de perméabilité, en présence de contraintes initiales, puis d’en discuter les avantages et les inconvénients sur la base d’une simulation du creusement d’un tunnel dans l’argile à Opalinus relatif à l’expérience SELFRAC. [less ▲]