Exploring a bounding surface SANICLAY plasticity model in capturing the cyclic threshold shear strains and modulus degradation of clays

Francesca Palmieri, Gaziz Seidalinov, Mahdi Taiebat

In the proceedings of: GeoOttawa 2017: 70th Canadian Geotechnical Conference; 12th joint with IAH-CNC

Session: Theoretical Soil Mechanics

ABSTRACT: Clay microstructure tends to deteriorate due to shear deformations, inducing an overall stiffness reduction and related increase of hysteretic damping according to the reached strain level for strain amplitudes ranging from small to large. Furthermore, under cyclic loading conditions additional modulus degradation and residual pore pressures develop with the number of loading cycles for medium to large strains. For an accurate description of such features in the macroscopic stress-strain response of clays, one would need to use advanced constitutive models. In this paper, the capabilities of the SANICLAY-B model in capturing the cyclic behavior of clays are investigated. A series of strain-controlled undrained cyclic simple shear tests are carried out and the evolution of excess pore pressures, and variations of shear modulus and damping are examined. Results are compared with the typical experimental ranges derived from the literature, showing that the SANICLAY-B succeeds in reproducing the stress-strain non-linearity and cyclic degradation. In addition, the influence of the relevant parameters is illustrated and discussed as a guide for an informed calibration process.

RÉSUMÉ: La microstructure de l'argile tend à se détériorer en raison de déformations de cisaillement, induisant une réduction globale de la rigidité et une augmentation de l'amortissement hystérétique du niveau de déformation atteint pour l'amplitude des déformations allant de petites à grandes. En outre, dans des conditions cycliques de chargement, la dégradation du module additionnel et les pressions interstitielles résiduelles se développent avec le nombre de cycles de chargement pour des deformations moyennes a grandes. Pour une description précise de ces caractéristiques dans la réponse macroscopique contrainte-déformation des argiles, il faudrait utiliser de lois de comportement avancées. Dans cet article, les capacités du modèle SANICLAY-de surpressions interstitielles et des variations du module de cisaillement et d'amortissement sont examinés. Les résultats sont comparés aux intervalles expérimentaux typiques dérivés de la littérature, montrant que SANICLAY-B réussit à reproduire la non-linéarité contrainte-déformation et la dégradation cyclique. En outre, l'influence des paramètres pertinents est illustrée et discutée comme une guide pour un processus d'étalonnage éclairé.

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Cite this article:
Francesca Palmieri; Gaziz Seidalinov; Mahdi Taiebat (2017) Exploring a bounding surface SANICLAY plasticity model in capturing the cyclic threshold shear strains and modulus degradation of clays in GEO2017. Ottawa, Ontario: Canadian Geotechnical Society.

@article{geo2017Paper773,author = Francesca Palmieri; Gaziz Seidalinov; Mahdi Taiebat,title = Exploring a bounding surface SANICLAY plasticity model in capturing the cyclic threshold shear strains and modulus degradation of clays,year = 2017}