Predicting behaviour of cemented clay considering strength reduction due to high confining pressure

Lam Nguyen, Behzad Fatahi, Hadi Khabbaz

In the proceedings of: GeoMontréal 2013: 66th Canadian Geotechnical Conference; 11th joint with IAH-CNC

Session: Soil Stabilization III

ABSTRACT: A predictive constitutive model referred to as Cemented Cam Clay (CCC) model developed by the authors is presented in this paper to precisely predict the behaviour of cemented clay capturing the effect of cementation degradation during loading. When the confining pressure increases, the effect of cementation gradually diminishes due to the breakdown of cementation bonds as observed in laboratory experiments. The proposed model includes a non-associated plastic potential function and elasto-plastic stress-strain relationship inspired by the framework of the critical state concept. The main feature of the proposed model is the formulation of the failure envelope which describes the beneficial effect of cementation at low pressure range. As the confining pressure continues to increase, it gradually merges with the critical state line indicating a degradation of cement bonding. The proposed model is validated through comparison of the model predictions with the results of an array of triaxial tests conducted on Ariake cemented clay.

RÉSUMÉ: Un prédictif modèle constitutif dénommé modèle « Cemented Cam Clay » (CCC) développé par les auteurs est présenté dans ce papier pour prévoir précisément le comportement des argiles cimentées capturant l™effet de la dégradation de cémentation pendant le chargement. Quand la pression de confinement augmente, l™effet de cimentation diminue progressivement grâce à la rupture des liens de cimentation comme observé dans les expériences de laboratoire. Le modèle proposé inclut une fonction de potentiel plastique non associé et une élasto-plastique relation contrainte-déformation inspirées par le cadre du concept d™état critique. La principale caractéristique du modèle proposé est la formulation de l™enveloppe de rupture qui décrit l'effet bénéfique de cimentation à une gamme basse pression. Comme la pression de confinement continue d™augmenter, il se confond peu à peu avec la ligne d™état critique indiquant une dégradation de la liaison du ciment. Le modèle proposé est validé par comparaison des modèles de prédiction avec les résultats d™une série de test triaxiaux réalisés sur argile cimentée « Ariake ».

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Cite this article:
Lam Nguyen; Behzad Fatahi; Hadi Khabbaz (2013) Predicting behaviour of cemented clay considering strength reduction due to high confining pressure in GEO2013. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GeoMon2013Paper780,author = Lam Nguyen; Behzad Fatahi; Hadi Khabbaz,title = Predicting behaviour of cemented clay considering strength reduction due to high confining pressure,year = 2013}