Documents disponibles écrits par cet auteur

Desiccation cracks in saturated fine-grained soils: particle-level phenomena and effective-stress analysis / H. Shin in Géotechnique, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 11 (Novembre 2010) . - pp. 961-972 Titre : Desiccation cracks in saturated fine-grained soils: particle-level phenomena and effective-stress analysis Type de document : texte imprimé Auteurs : H. Shin, Auteur ; J. C. Santamarina, Auteur Année de publication : 2011 Article en page(s) : pp. 961-972 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Failure  Clays  Suction  Theoretical  analysis Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : The formation of desiccation cracks in soils is often interpreted in terms of tensile strength. However, this mechanistic model disregards the cohesionless, effective-stress-dependent frictional behaviour of fine-grained soils. An alternative theory is explored using analyses, numerical simulations based on an effective-stress formulation, and experiments monitored using high-resolution time-lapsed photography. Results show that desiccation cracks in fine-grained sediments initiate as the air–water interface invades the saturated medium, driven by the increase in suction. Thereafter, the interfacial membrane causes an increase in the local void ratio at the tip, the air-entry value decreases, the air–water interface advances into the tip and the crack grows. The effective stress remains in compression everywhere in the soil mass, including at the tip of the desiccation crack. This crack-growing mechanism can explain various observations related to desiccation crack formation in fine-grained soils, including the effects of pore fluid salt concentration, slower crack propagation velocity and right angle realignment while approaching a pre-existing crack, and the apparent strength and failure mode observed in fine-grained soils subjected to tension. Additional research is required to develop a complementary phenomenological model for desiccation crack formation in coarse-grained sediments. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.012 [article] Desiccation cracks in saturated fine-grained soils: particle-level phenomena and effective-stress analysis [texte imprimé] / H. Shin, Auteur ; J. C. Santamarina, Auteur . - 2011 . - pp. 961-972. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 11 (Novembre 2010) . - pp. 961-972 Mots-clés : Failure  Clays  Suction  Theoretical  analysis Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : The formation of desiccation cracks in soils is often interpreted in terms of tensile strength. However, this mechanistic model disregards the cohesionless, effective-stress-dependent frictional behaviour of fine-grained soils. An alternative theory is explored using analyses, numerical simulations based on an effective-stress formulation, and experiments monitored using high-resolution time-lapsed photography. Results show that desiccation cracks in fine-grained sediments initiate as the air–water interface invades the saturated medium, driven by the increase in suction. Thereafter, the interfacial membrane causes an increase in the local void ratio at the tip, the air-entry value decreases, the air–water interface advances into the tip and the crack grows. The effective stress remains in compression everywhere in the soil mass, including at the tip of the desiccation crack. This crack-growing mechanism can explain various observations related to desiccation crack formation in fine-grained soils, including the effects of pore fluid salt concentration, slower crack propagation velocity and right angle realignment while approaching a pre-existing crack, and the apparent strength and failure mode observed in fine-grained soils subjected to tension. Additional research is required to develop a complementary phenomenological model for desiccation crack formation in coarse-grained sediments. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.012

Role of particle angularity on the mechanical behavior of granular mixtures / H. Shin in Journal of geotechnical and geoenvironmental engineering, Vol. 139 N° 2 (Février 2013) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 2 (Février 2013) . - pp. 353-355 Titre : Role of particle angularity on the mechanical behavior of granular mixtures Type de document : texte imprimé Auteurs : H. Shin, Auteur ; J. C. Santamarina, Auteur Année de publication : 2013 Article en page(s) : pp. 353-355 Note générale : geotechnique Langues : Anglais (eng) Mots-clés : particles;  shape;  coefficients;  earth  pressure;  shear  waves;  wave  velocity;  granular  media;  mixtures;  mechanical  properties;  compression Résumé : Particle shape affects the mechanical behavior of soils, including packing density, stiffness, volume change during shear, and strength. Laboratory experiments conducted to study the mechanical response of sand mixtures made of round and angular grains show an increase in void ratio, small strain shear modulus Gmax (constant fabric), oedometric compressibility CC (fabric changes), and friction angle but a decrease in lateral stress coefficient k0 as the mass fraction of angular particles increases. These results reflect variations in particle mobility and highlight the relative role of contact stiffness versus fabric changes. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000768 [article] Role of particle angularity on the mechanical behavior of granular mixtures [texte imprimé] / H. Shin, Auteur ; J. C. Santamarina, Auteur . - 2013 . - pp. 353-355. geotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 2 (Février 2013) . - pp. 353-355 Mots-clés : particles;  shape;  coefficients;  earth  pressure;  shear  waves;  wave  velocity;  granular  media;  mixtures;  mechanical  properties;  compression Résumé : Particle shape affects the mechanical behavior of soils, including packing density, stiffness, volume change during shear, and strength. Laboratory experiments conducted to study the mechanical response of sand mixtures made of round and angular grains show an increase in void ratio, small strain shear modulus Gmax (constant fabric), oedometric compressibility CC (fabric changes), and friction angle but a decrease in lateral stress coefficient k0 as the mass fraction of angular particles increases. These results reflect variations in particle mobility and highlight the relative role of contact stiffness versus fabric changes. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000768