Documents disponibles écrits par cet auteur

Effect of strain rate on the stress-strain behavior of sand / Jerry A. Yamamuro in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 12 (Décembre 2011) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 12 (Décembre 2011) . - pp. 1169-1178 Titre : Effect of strain rate on the stress-strain behavior of sand Type de document : texte imprimé Auteurs : Jerry A. Yamamuro, Auteur ; Antonio E. Abrantes, Auteur ; Poul V. Lade, Auteur Année de publication : 2012 Article en page(s) : pp. 1169-1178 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Global  strain  Image  analysis  Local  strain  Photography  Sand  Strain  Strain  rate  Stress  strain  Transient  testing  Triaxial  tests Résumé : Drained triaxial compression tests on crushed coral sand were performed from near-static strain rates to very high strain rates (up to approximately 1,800%/s). Experiments were performed on dry, vacuum-confined axisymmetric specimens at two different confining pressures (98 and 350 kPa) and two different densities (Dr approximately 36 and 60%). A gravity drop weight loading system was used to generate high strain rates. High-speed film photographs of the specimen were taken through the flat sides of a square triaxial cell. By using digital image analysis techniques, strains were locally measured near the center of the specimen to obtain the most uniform assessment. Stress-strain relationships are presented. The following effects were observed with increasing strain rates: the elastoplastic stiffness increased significantly; the failure shear strength increased moderately; the axial strain at peak stress decreased significantly; and volumetric strains became more dilatant. Unusual behavior was observed at very high strain rates. Examples include the peak stress was not always associated with the maximum dilatancy rate and shear band inclination angle was noticeably reduced. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i12/p1169_s1?isAuthorized=no [article] Effect of strain rate on the stress-strain behavior of sand [texte imprimé] / Jerry A. Yamamuro, Auteur ; Antonio E. Abrantes, Auteur ; Poul V. Lade, Auteur . - 2012 . - pp. 1169-1178. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 12 (Décembre 2011) . - pp. 1169-1178 Mots-clés : Global  strain  Image  analysis  Local  strain  Photography  Sand  Strain  Strain  rate  Stress  strain  Transient  testing  Triaxial  tests Résumé : Drained triaxial compression tests on crushed coral sand were performed from near-static strain rates to very high strain rates (up to approximately 1,800%/s). Experiments were performed on dry, vacuum-confined axisymmetric specimens at two different confining pressures (98 and 350 kPa) and two different densities (Dr approximately 36 and 60%). A gravity drop weight loading system was used to generate high strain rates. High-speed film photographs of the specimen were taken through the flat sides of a square triaxial cell. By using digital image analysis techniques, strains were locally measured near the center of the specimen to obtain the most uniform assessment. Stress-strain relationships are presented. The following effects were observed with increasing strain rates: the elastoplastic stiffness increased significantly; the failure shear strength increased moderately; the axial strain at peak stress decreased significantly; and volumetric strains became more dilatant. Unusual behavior was observed at very high strain rates. Examples include the peak stress was not always associated with the maximum dilatancy rate and shear band inclination angle was noticeably reduced. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i12/p1169_s1?isAuthorized=no

Stress-strain and strength characteristics of silt-clay transition soils / Pongpipat Anantanasakul in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 10 (Octobre 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 10 (Octobre 2012) . - pp.1257–1265. Titre : Stress-strain and strength characteristics of silt-clay transition soils Type de document : texte imprimé Auteurs : Pongpipat Anantanasakul, Auteur ; Jerry A. Yamamuro, Auteur ; Victor N. Kaliakin, Auteur Année de publication : 2013 Article en page(s) : pp.1257–1265. Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Clay  Silt  content  Anisotropy  Stress-strain  behavior Résumé : The influence of nonplastic silt content on the stress-strain, volume change, and strength characteristics of anisotropic silt-clay transition soils is investigated. A series of one-dimensional compression tests, isotropic compression tests, and undrained and drained triaxial tests on three soils of similar base clay but different nonplastic silt contents are performed on cross-anisotropic specimens prepared from consolidation of slurries. Tests with major loading directions both parallel and perpendicular to the specimens’ axis of deposition are performed. It is observed that the tested silt-clay soils are less compressible with increasing silt content during one-dimensional and isotropic compression tests. During drained and undrained triaxial tests, the normally consolidated soils at the same consolidation stress show larger values of stiffness and drained and undrained shear strengths with increasing silt content. The silt-clay soils also show larger pore pressure changes during undrained triaxial tests but essentially similar volumetric strains during drained tests as the silt content increases. In addition, it is observed that silt content significantly influences the anisotropy of the stress-strain and strength characteristics of the transition silt-clay soils. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000692 [article] Stress-strain and strength characteristics of silt-clay transition soils [texte imprimé] / Pongpipat Anantanasakul, Auteur ; Jerry A. Yamamuro, Auteur ; Victor N. Kaliakin, Auteur . - 2013 . - pp.1257–1265. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 10 (Octobre 2012) . - pp.1257–1265. Mots-clés : Clay  Silt  content  Anisotropy  Stress-strain  behavior Résumé : The influence of nonplastic silt content on the stress-strain, volume change, and strength characteristics of anisotropic silt-clay transition soils is investigated. A series of one-dimensional compression tests, isotropic compression tests, and undrained and drained triaxial tests on three soils of similar base clay but different nonplastic silt contents are performed on cross-anisotropic specimens prepared from consolidation of slurries. Tests with major loading directions both parallel and perpendicular to the specimens’ axis of deposition are performed. It is observed that the tested silt-clay soils are less compressible with increasing silt content during one-dimensional and isotropic compression tests. During drained and undrained triaxial tests, the normally consolidated soils at the same consolidation stress show larger values of stiffness and drained and undrained shear strengths with increasing silt content. The silt-clay soils also show larger pore pressure changes during undrained triaxial tests but essentially similar volumetric strains during drained tests as the silt content increases. In addition, it is observed that silt content significantly influences the anisotropy of the stress-strain and strength characteristics of the transition silt-clay soils. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000692