Documents disponibles écrits par cet auteur

Behavior of a compacted completely decomposed granite soil from suction controlled direct shear tests / Md. Akhtar Hossain in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 1 (Janvier 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 189-198 Titre : Behavior of a compacted completely decomposed granite soil from suction controlled direct shear tests Type de document : texte imprimé Auteurs : Md. Akhtar Hossain, Auteur ; Yin, Jian-Hua, Auteur Article en page(s) : pp. 189-198 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Shear  strength  Completely  decomposed  granite  Matric  suction  Soil  dilatancy  Axis-translation  technique  Direct  shear Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A series of single-staged consolidated drained direct shear tests are carried out on recompacted completely decomposed granite (CDG) soil—a typical residual soil in Hong Kong, under different matric suctions and net normal stresses. Matric suction is controlled by applying air pressure in the pressure chamber and water pressure at the bottom of the high air-entry ceramic disk. The experimental results show that the contribution of suction to shear strength is significant. Shear strength of CDG soil increases with the increase of matric suction. Net normal stress has a remarkable influence on the shear strength of unsaturated CDG soil. The increase in shear strength due to an increase in matric suction (suction envelope) is observed as nonlinear i.e., phib value varies with matric suction. No soil dilatancy is observed for zero matric suction (saturated case) but as the suction value is increased, higher soil dilatancy is obvious in lower net normal stresses. The rate of increase of soil dilatancy is greater in lower suction range than in higher suction range. The experimental shear strength data match closely with the shear strength predicted by existing shear strength model considering the soil-dilation effect. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&ONLINE=YES&s [...] [article] Behavior of a compacted completely decomposed granite soil from suction controlled direct shear tests [texte imprimé] / Md. Akhtar Hossain, Auteur ; Yin, Jian-Hua, Auteur . - pp. 189-198. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 189-198 Mots-clés : Shear  strength  Completely  decomposed  granite  Matric  suction  Soil  dilatancy  Axis-translation  technique  Direct  shear Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A series of single-staged consolidated drained direct shear tests are carried out on recompacted completely decomposed granite (CDG) soil—a typical residual soil in Hong Kong, under different matric suctions and net normal stresses. Matric suction is controlled by applying air pressure in the pressure chamber and water pressure at the bottom of the high air-entry ceramic disk. The experimental results show that the contribution of suction to shear strength is significant. Shear strength of CDG soil increases with the increase of matric suction. Net normal stress has a remarkable influence on the shear strength of unsaturated CDG soil. The increase in shear strength due to an increase in matric suction (suction envelope) is observed as nonlinear i.e., phib value varies with matric suction. No soil dilatancy is observed for zero matric suction (saturated case) but as the suction value is increased, higher soil dilatancy is obvious in lower net normal stresses. The rate of increase of soil dilatancy is greater in lower suction range than in higher suction range. The experimental shear strength data match closely with the shear strength predicted by existing shear strength model considering the soil-dilation effect. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&ONLINE=YES&s [...]

Influence of grouting pressure on the behavior of an unsaturated soil-cement interface / Md. Akhtar Hossain in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 2 (Fevrier 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 2 (Fevrier 2012) . - pp. 193-202 Titre : Influence of grouting pressure on the behavior of an unsaturated soil-cement interface Type de document : texte imprimé Auteurs : Md. Akhtar Hossain, Auteur ; Yin, Jian-Hua, Auteur Année de publication : 2012 Article en page(s) : pp. 193-202 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Grouting  pressure  Matric  suction  CDG  soil  Cement  grout  Interface  Direct  shear Résumé : The strength of soil-nails depends on the behavior of the soil-cement grout interface at saturated and unsaturated conditions. Nowadays, pressure grouted soil-nails are considered to provide better interface strength than gravity grouted soil-nails. Soil-nail pullout tests have limitations to control some boundary conditions. To overcome these limitations, direct shear tests can be used to determine the actual soil-cement grout interface behavior. In the present study, a series of interface direct shear tests are performed between compacted completely decomposed granite (CDG) soil and cement grout at both saturated and unsaturated conditions under different grouting pressures. The interface shear stress increases with matric suction for different grouting pressures, and a strain softening behavior is observed for different suctions except at saturated conditions. A dilative behavior is obvious for interface as the suction value is increased from a saturated condition. However, the dilation values of soil-cement interface for different grouting pressures are less than that of CDG soil under different suctions. The interface shear strength increases with grouting pressure at saturated conditions, whereas, a downward trend is obvious as the suction value is increased from saturated conditions. The rate of increase of shear strength with matric suction is greater for CDG soil compared to soil-cement interface. Interface shear strengths for different grouting pressures are greater than CDG soil at a lower suction range but become less than CDG soil at a higher suction range. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i2/p193_s1?isAuthorized=no [article] Influence of grouting pressure on the behavior of an unsaturated soil-cement interface [texte imprimé] / Md. Akhtar Hossain, Auteur ; Yin, Jian-Hua, Auteur . - 2012 . - pp. 193-202. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 2 (Fevrier 2012) . - pp. 193-202 Mots-clés : Grouting  pressure  Matric  suction  CDG  soil  Cement  grout  Interface  Direct  shear Résumé : The strength of soil-nails depends on the behavior of the soil-cement grout interface at saturated and unsaturated conditions. Nowadays, pressure grouted soil-nails are considered to provide better interface strength than gravity grouted soil-nails. Soil-nail pullout tests have limitations to control some boundary conditions. To overcome these limitations, direct shear tests can be used to determine the actual soil-cement grout interface behavior. In the present study, a series of interface direct shear tests are performed between compacted completely decomposed granite (CDG) soil and cement grout at both saturated and unsaturated conditions under different grouting pressures. The interface shear stress increases with matric suction for different grouting pressures, and a strain softening behavior is observed for different suctions except at saturated conditions. A dilative behavior is obvious for interface as the suction value is increased from a saturated condition. However, the dilation values of soil-cement interface for different grouting pressures are less than that of CDG soil under different suctions. The interface shear strength increases with grouting pressure at saturated conditions, whereas, a downward trend is obvious as the suction value is increased from saturated conditions. The rate of increase of shear strength with matric suction is greater for CDG soil compared to soil-cement interface. Interface shear strengths for different grouting pressures are greater than CDG soil at a lower suction range but become less than CDG soil at a higher suction range. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i2/p193_s1?isAuthorized=no