Documents disponibles écrits par cet auteur

Characterization of cemented sand by experimental and numerical investigations / Y. H. Wang in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°7 (Juillet 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°7 (Juillet 2008) . - pp. 992–1004 Titre : Characterization of cemented sand by experimental and numerical investigations Type de document : texte imprimé Auteurs : Y. H. Wang, Auteur ; S. C. Leung, Auteur Année de publication : 2008 Article en page(s) : pp. 992–1004 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Discrete  elements  Stress  Bonding  Banding  Triaxial  tests  Dilatancy Résumé : In this study, the effects of cementation on the stress–dilatancy and strength of cemented sand are investigated through experimental characterizations using triaxial tests and numerical simulations using the discrete element method. At small strains, dilatancy is hindered by the intact bonding network that produces a web-patterned force chain. After yielding, the increase in the dilatancy accelerates. Two competing but intimately related processes determine the peak strength: Bond breakages cause a strength reduction but the associated dilatancy leads to a strength increase. This finding and the experimental observation that the dilatancy at the peak state increases with increasing cement content explain why the measured peak-state strength parameters, c′ and ϕ′p , are relevant to the cement content. With increasing strain, the force-chain distribution gradually changes to a thick columnar shape, which mostly appears inside the shear band. At the ultimate state, the cementing bonds remain to form clusters, even within the shear band. The existence of clusters not only helps maintain the overall volumetric dilation but also prevents force-chain buckling, which in turn increases the associated strength. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A7%2899 [...] [article] Characterization of cemented sand by experimental and numerical investigations [texte imprimé] / Y. H. Wang, Auteur ; S. C. Leung, Auteur . - 2008 . - pp. 992–1004. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°7 (Juillet 2008) . - pp. 992–1004 Mots-clés : Discrete  elements  Stress  Bonding  Banding  Triaxial  tests  Dilatancy Résumé : In this study, the effects of cementation on the stress–dilatancy and strength of cemented sand are investigated through experimental characterizations using triaxial tests and numerical simulations using the discrete element method. At small strains, dilatancy is hindered by the intact bonding network that produces a web-patterned force chain. After yielding, the increase in the dilatancy accelerates. Two competing but intimately related processes determine the peak strength: Bond breakages cause a strength reduction but the associated dilatancy leads to a strength increase. This finding and the experimental observation that the dilatancy at the peak state increases with increasing cement content explain why the measured peak-state strength parameters, c′ and ϕ′p , are relevant to the cement content. With increasing strain, the force-chain distribution gradually changes to a thick columnar shape, which mostly appears inside the shear band. At the ultimate state, the cementing bonds remain to form clusters, even within the shear band. The existence of clusters not only helps maintain the overall volumetric dilation but also prevents force-chain buckling, which in turn increases the associated strength. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A7%2899 [...]

Mechanisms of small-strain shear-modulus anisotropy in soils / Y. H. Wang in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°10 (Octobre 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°10 (Octobre 2008) . - pp. 1516–1530 Titre : Mechanisms of small-strain shear-modulus anisotropy in soils Type de document : texte imprimé Auteurs : Y. H. Wang, Auteur ; C. M. Mok, Auteur Année de publication : 2008 Article en page(s) : pp. 1516–1530 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Shear  modulus  Anisotropy  Soil  structures  Stiffness  Contact  pressure Résumé : In this paper, experimental studies using a true triaxial apparatus and a bender element system, and numerical simulations based on the discrete element method (DEM) were used to investigate the stress- and fabric-induced shear-stiffness anisotropy in soils at small strains. Verified by experiments and DEM simulations, the shear modulus was found to be relatively independent of the out-of-plane stress component, which can be revealed by the indistinctive change in the contact normal distribution and the normal contact forces on that plane in the DEM simulations. Simulation and experimental results also demonstrated that the shear modulus is equally contributed by the two principal stress components on the associated shearing planes. Fabric-induced stiffness anisotropy, i.e., the highest Gxy or Ghh , can be explained by simulation findings in which more contact normals prefer to distribute along the horizontal direction. The experiments and simulations also reveal that the fabric-induced stiffness anisotropy increases with an increasing aspect ratio of the particles. The assumption of transversely isotropic fabric in soils is valid based on the DEM simulation results; however, this assumption is not completely supported by the experimental results. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A10%281 [...] [article] Mechanisms of small-strain shear-modulus anisotropy in soils [texte imprimé] / Y. H. Wang, Auteur ; C. M. Mok, Auteur . - 2008 . - pp. 1516–1530. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°10 (Octobre 2008) . - pp. 1516–1530 Mots-clés : Shear  modulus  Anisotropy  Soil  structures  Stiffness  Contact  pressure Résumé : In this paper, experimental studies using a true triaxial apparatus and a bender element system, and numerical simulations based on the discrete element method (DEM) were used to investigate the stress- and fabric-induced shear-stiffness anisotropy in soils at small strains. Verified by experiments and DEM simulations, the shear modulus was found to be relatively independent of the out-of-plane stress component, which can be revealed by the indistinctive change in the contact normal distribution and the normal contact forces on that plane in the DEM simulations. Simulation and experimental results also demonstrated that the shear modulus is equally contributed by the two principal stress components on the associated shearing planes. Fabric-induced stiffness anisotropy, i.e., the highest Gxy or Ghh , can be explained by simulation findings in which more contact normals prefer to distribute along the horizontal direction. The experiments and simulations also reveal that the fabric-induced stiffness anisotropy increases with an increasing aspect ratio of the particles. The assumption of transversely isotropic fabric in soils is valid based on the DEM simulation results; however, this assumption is not completely supported by the experimental results. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A10%281 [...]