Documents disponibles écrits par cet auteur

Critical state of granular materials based on the sliding-rolling theory / A. Anandarajah in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°1 (Janvier 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°1 (Janvier 2008) . - pp. 125–135 Titre : Critical state of granular materials based on the sliding-rolling theory Type de document : texte imprimé Auteurs : A. Anandarajah, Auteur Année de publication : 2008 Article en page(s) : pp. 125–135 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Granular  materials  Sliding  Stress  strain  relations Résumé : By representing the assembly by a simplified column model, a constitutive theory was recently developed for a two-dimensional assembly of rods. This theory, referred to as the sliding-rolling theory, is extended in this paper to represent the triaxial stress-strain behavior of granular materials. The sliding-rolling theory provides a dilatancy rule and an expression for the slope of the line of zero dilatancy in the stress space. These rules are then combined with triaxial observations to provide a microstructural interpretation of the critical state of granular materials. According to the theory, the slope of the critical state line in the stress space depends on the interparticle friction angle and the degree of contact normal anisotropy. To verify the basic ideas of the sliding-rolling theory, numerical experiments are conducted using the discrete-element method on three-dimensional assemblies of spheres. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A1%2812 [...] [article] Critical state of granular materials based on the sliding-rolling theory [texte imprimé] / A. Anandarajah, Auteur . - 2008 . - pp. 125–135. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°1 (Janvier 2008) . - pp. 125–135 Mots-clés : Granular  materials  Sliding  Stress  strain  relations Résumé : By representing the assembly by a simplified column model, a constitutive theory was recently developed for a two-dimensional assembly of rods. This theory, referred to as the sliding-rolling theory, is extended in this paper to represent the triaxial stress-strain behavior of granular materials. The sliding-rolling theory provides a dilatancy rule and an expression for the slope of the line of zero dilatancy in the stress space. These rules are then combined with triaxial observations to provide a microstructural interpretation of the critical state of granular materials. According to the theory, the slope of the critical state line in the stress space depends on the interparticle friction angle and the degree of contact normal anisotropy. To verify the basic ideas of the sliding-rolling theory, numerical experiments are conducted using the discrete-element method on three-dimensional assemblies of spheres. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A1%2812 [...]

Microstructural investigation of soil suction and hysteresis of fine-grained soils / A. Anandarajah in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 1 (Janvier 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 1 (Janvier 2012) . - pp. 38-46 Titre : Microstructural investigation of soil suction and hysteresis of fine-grained soils Type de document : texte imprimé Auteurs : A. Anandarajah, Auteur ; Priyanthi M. Amarasinghe, Auteur Année de publication : 2012 Article en page(s) : pp. 38-46 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Montmorillonite  Kaolinite  Molecular  dynamics  Discrete-element  method  SWCC  Soil  suction  Inkbottle  effect  Contact  angle  Surface  tension Résumé : The relationship between soil suction and degree of water saturation (also known as the soil-water characteristic curve or SWCC) for a given soil depends on a number of variables such as the soil type, mineral type, fluid type, pore size distribution, and anisotropy. In addition, the SWCC is found to exhibit a form of hysteresis, in that it is different in wetting and drying. Design of structures founded on unsaturated soils requires an in-depth microscopic understanding of the variables controlling SWCC and the underlying hysteresis. Most of the past basic studies have focused on granular materials, with solid particles represented by spheres. The present study is focused on clayey soils involving platelike solids. The analysis method of molecular dynamics (MD) is used to understand the nature of clay-water capillary meniscus. On the basis of the observations from the MD analysis and the Young-Laplace equation, a model is proposed for predicting SWCC and the associated hysteresis. The microscopic parameters needed for the model are obtained by analyzing the fabric of numerical specimens prepared by the discrete-element method (DEM) of analysis of an assembly of clay particles. The results are shown to be consistent with experimental observations. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i1/p38_s1?isAuthorized=no [article] Microstructural investigation of soil suction and hysteresis of fine-grained soils [texte imprimé] / A. Anandarajah, Auteur ; Priyanthi M. Amarasinghe, Auteur . - 2012 . - pp. 38-46. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 1 (Janvier 2012) . - pp. 38-46 Mots-clés : Montmorillonite  Kaolinite  Molecular  dynamics  Discrete-element  method  SWCC  Soil  suction  Inkbottle  effect  Contact  angle  Surface  tension Résumé : The relationship between soil suction and degree of water saturation (also known as the soil-water characteristic curve or SWCC) for a given soil depends on a number of variables such as the soil type, mineral type, fluid type, pore size distribution, and anisotropy. In addition, the SWCC is found to exhibit a form of hysteresis, in that it is different in wetting and drying. Design of structures founded on unsaturated soils requires an in-depth microscopic understanding of the variables controlling SWCC and the underlying hysteresis. Most of the past basic studies have focused on granular materials, with solid particles represented by spheres. The present study is focused on clayey soils involving platelike solids. The analysis method of molecular dynamics (MD) is used to understand the nature of clay-water capillary meniscus. On the basis of the observations from the MD analysis and the Young-Laplace equation, a model is proposed for predicting SWCC and the associated hysteresis. The microscopic parameters needed for the model are obtained by analyzing the fabric of numerical specimens prepared by the discrete-element method (DEM) of analysis of an assembly of clay particles. The results are shown to be consistent with experimental observations. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i1/p38_s1?isAuthorized=no

Modeling liquefaction by a multimechanism model / A. Anandarajah 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. 949–959 Titre : Modeling liquefaction by a multimechanism model Type de document : texte imprimé Auteurs : A. Anandarajah, Auteur Année de publication : 2008 Article en page(s) : pp. 949–959 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Liquefaction  Elastoplasticity  Granular  materials  Anisotropy  Stress  strain  relations Résumé : An anisotropic constitutive model was recently presented for describing the stress–strain behavior of granular materials with considerations for the initial and induced anisotropy. The model was developed within the framework of a microstructural theory known as the sliding–rolling theory. The resulting model falls within the definition of multimechanism models. The model was shown to satisfactorily represent the drained and undrained behaviors under monotonic loading. The framework used in the model allows extension to describe the behavior under cyclic loading, which is the subject of the present paper. Specifically, the model is further developed for representing the undrained behavior of granular materials under one- and two-way cyclic loading, some of which cause liquefaction resulting in large strain accumulations and the others lead to limited pore pressure and strain accumulations. The validity of the model is verified using triaxial data on Nevada sand. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A7%2894 [...] [article] Modeling liquefaction by a multimechanism model [texte imprimé] / A. Anandarajah, Auteur . - 2008 . - pp. 949–959. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°7 (Juillet 2008) . - pp. 949–959 Mots-clés : Liquefaction  Elastoplasticity  Granular  materials  Anisotropy  Stress  strain  relations Résumé : An anisotropic constitutive model was recently presented for describing the stress–strain behavior of granular materials with considerations for the initial and induced anisotropy. The model was developed within the framework of a microstructural theory known as the sliding–rolling theory. The resulting model falls within the definition of multimechanism models. The model was shown to satisfactorily represent the drained and undrained behaviors under monotonic loading. The framework used in the model allows extension to describe the behavior under cyclic loading, which is the subject of the present paper. Specifically, the model is further developed for representing the undrained behavior of granular materials under one- and two-way cyclic loading, some of which cause liquefaction resulting in large strain accumulations and the others lead to limited pore pressure and strain accumulations. The validity of the model is verified using triaxial data on Nevada sand. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A7%2894 [...]