Simulation of the Cyclic Response of Anisotropic Clay through Bounding Surface Viscoplasticity
Mohammad Zarrabi, Zhenhao Shi, Samuel Yniesta, Giuseppe Buscarnera
In the proceedings of: GeoVirtual 2020: 73rd Canadian Geotechnical ConferenceABSTRACT: In this study, a recently developed framework referred to as bounding surface elasto-viscoplasticity (BS-EVP) is used to combine bounding surface concepts and the Perzyna’s overstress theory, thus enabling the simulation of rate effects for general degrees of overconsolidation. At variance with previous analyses, the model proposed here suppresses the hypothesis of isotropy and enables the simulation of fabric effects through rotational hardening. For this purpose, the SANICLAY model is recast in light of the BS-EVP framework by enabling the growth of the overstress and the consequent accumulation of viscous strain within the bounding surface. It is shown that the resulting constitutive model captures the dependence of the undrained strength of clays on the loading rates. Additionally, by employing a proper repositioning of the projection center and a hybrid flow rule, the performance of the model is improved to make it a robust model for cyclic loading applications and cyclic softening analysis.
RÉSUMÉ: Dans cette étude, le concept récemment développé appelé élasto-viscoplasticité à surface limitante (BS-EVP) est utilisé pour combiner les concepts de surface limitante et la théorie de contraintes excessives de Perzyna, permettant ainsi la modélisation des effets de taux de déformation pour différents degrés de surconsolidation. Contrairement aux analyses précédentes, le modèle proposé ici supprime l'hypothèse d'isotropie et permet de simuler les effets de structure par écrouissage rotationnel. Dans ce but, le modèle SANICLAY est refurmulé avec le concept de BS-EVP en permettant la croissance de contraintes excessives et l'accumulation conséquente de déformation visqueuse dans la surface limite. Il est montré que la loi de comportement résultant saisit la dépendance de la résistance non drainée des argiles sur les taux de chargement. De plus, en utilisant un repositionnement approprié du centre de projection et une règle d’écoulement plastique hybride, les performances du modèle sont améliorées pour en faire un modèle robuste pour les applications de chargement cyclique et l'analyse de ramollissement cyclique.
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Zarrabi, Mohammad, Shi, Zhenhao, Yniesta, Samuel, Buscarnera, Giuseppe (2020) Simulation of the Cyclic Response of Anisotropic Clay through Bounding Surface Viscoplasticity in GEO2020. Ottawa, Ontario: Canadian Geotechnical Society.
@article{Zarrabi_GEO2020_246,
author = {Zarrabi, Mohammad}, {Shi, Zhenhao}, {Yniesta, Samuel}, {Buscarnera, Giuseppe},
title = Simulation of the Cyclic Response of Anisotropic Clay through Bounding Surface Viscoplasticity ,
year = 2020
}
title = Simulation of the Cyclic Response of Anisotropic Clay through Bounding Surface Viscoplasticity ,
year = 2020
}