Documents disponibles écrits par cet auteur

Class A prediction of the behavior of soft estuarine soil foundation stabilized by short vertical drains beneath a rail track / Buddhima Indraratna in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 5 (Mai 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 5 (Mai 2010) . - pp. 686-696 Titre : Class A prediction of the behavior of soft estuarine soil foundation stabilized by short vertical drains beneath a rail track Type de document : texte imprimé Auteurs : Buddhima Indraratna, Auteur ; Cholachat Rujikiatkamjorn, Auteur ; Brook Ewers, Auteur Année de publication : 2010 Article en page(s) : pp. 686-696 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Clays  Cyclic  loads  Laboratory  tests  Railroad  engineering  Subsurface  drainage Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : In Australia, very few rail tracks have been constructed directly on deep estuarine deposits. In recent years, Kooragang Island has become a major export terminal and most coal trains need to cross the main lines at Sandgate to enter Kooragang Island. In this study, a rail track built on up to 30 m of thick soft estuarine soil was stabilized with relatively short vertical drains to consolidate the soil just beneath the track, and no additional preloading surcharge was provided, except the weight from the trains. The initial soil compression was caused by the passage of trains with a speed restricted at 40 km/h. From this study, it is shown that prefabricated vertical drains significantly decrease the buildup of excess pore-water pressure during cyclic loading, and also continue to dissipate excess pore-water pressure during the rest period. A preliminary finite-element analysis was employed to examine the performance of vertical drains, and a Class A prediction was obtained in terms of lateral and vertical displacements. The monitored settlement and lateral displacement results are presented and discussed. The study shows that relatively short vertical drains are sufficient for providing stability for rail tracks, without the need for driving deep vertical drains through the entire soft soil depth. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i5/p686_s1?isAuthorized=no [article] Class A prediction of the behavior of soft estuarine soil foundation stabilized by short vertical drains beneath a rail track [texte imprimé] / Buddhima Indraratna, Auteur ; Cholachat Rujikiatkamjorn, Auteur ; Brook Ewers, Auteur . - 2010 . - pp. 686-696. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 5 (Mai 2010) . - pp. 686-696 Mots-clés : Clays  Cyclic  loads  Laboratory  tests  Railroad  engineering  Subsurface  drainage Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : In Australia, very few rail tracks have been constructed directly on deep estuarine deposits. In recent years, Kooragang Island has become a major export terminal and most coal trains need to cross the main lines at Sandgate to enter Kooragang Island. In this study, a rail track built on up to 30 m of thick soft estuarine soil was stabilized with relatively short vertical drains to consolidate the soil just beneath the track, and no additional preloading surcharge was provided, except the weight from the trains. The initial soil compression was caused by the passage of trains with a speed restricted at 40 km/h. From this study, it is shown that prefabricated vertical drains significantly decrease the buildup of excess pore-water pressure during cyclic loading, and also continue to dissipate excess pore-water pressure during the rest period. A preliminary finite-element analysis was employed to examine the performance of vertical drains, and a Class A prediction was obtained in terms of lateral and vertical displacements. The monitored settlement and lateral displacement results are presented and discussed. The study shows that relatively short vertical drains are sufficient for providing stability for rail tracks, without the need for driving deep vertical drains through the entire soft soil depth. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i5/p686_s1?isAuthorized=no

Design procedure for vertical drains considering a linear variation of lateral permeability within the smear zone / Cholachat Rujikiatkamjorn in Canadian geotechnical journal, Vol. 46 N° 3 (Mars 2009) 

Public ISBD [article]  in Canadian geotechnical journal > Vol. 46 N° 3 (Mars 2009) . - pp. 270–280 Titre : Design procedure for vertical drains considering a linear variation of lateral permeability within the smear zone Type de document : texte imprimé Auteurs : Cholachat Rujikiatkamjorn, Auteur ; Buddhima Indraratna, Auteur Article en page(s) : pp. 270–280 Note générale : Sciences de la Terre Langues : Anglais (eng) Mots-clés : Consolidation  Design  charts  Smear  zone  Vertical  drains  Consolidation  Tableaux  de  conception  Zone  de  souillure  Drains  verticaux Index. décimale : 550 Sciences auxiliaires de la géologie. Résumé : A system of vertical drains with surcharge preloading is an effective method for promoting radial drainage and accelerated soil consolidation. This study presents a procedure for the design of vertical drains that significantly extends the previous technique proposed by the authors to include: (i) a linear reduction of lateral permeability in the smear zone, (ii) the effect of overlapping smear zones in a closely spaced drain network, and (iii) the gain in undrained shear strength due to consolidation. Design examples are provided for both single stage and multi-stage embankment construction demonstrating the convenient use of the proposed solutions in practical situations. Un système de drains verticaux avec pré-chargement en surcharge est un moyen efficace d’encourager le drainage radial et d’accélérer la consolidation du sol. Cette étude présente une procédure pour la conception de drains verticaux qui étend de façon significative la technique proposée précédemment par les auteurs pour inclure: (i) une réduction linéaire de la perméabilité linéaire dans la zone de souillure, (ii) l’effet de zones de souillure se chevauchant dans un réseau de drains situé dans espace restreint et (iii) le gain de résistance au cisaillement dû à la consolidation. Des exemples sont fournis pour des constructions de digues en une ou plusieurs étapes démontrant l’utilisation des solutions proposées pour des situations pratiques. DEWEY : 550 ISSN : 0008-3674 En ligne : http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=f [...] [article] Design procedure for vertical drains considering a linear variation of lateral permeability within the smear zone [texte imprimé] / Cholachat Rujikiatkamjorn, Auteur ; Buddhima Indraratna, Auteur . - pp. 270–280. Sciences de la Terre Langues : Anglais (eng) in Canadian geotechnical journal > Vol. 46 N° 3 (Mars 2009) . - pp. 270–280 Mots-clés : Consolidation  Design  charts  Smear  zone  Vertical  drains  Consolidation  Tableaux  de  conception  Zone  de  souillure  Drains  verticaux Index. décimale : 550 Sciences auxiliaires de la géologie. Résumé : A system of vertical drains with surcharge preloading is an effective method for promoting radial drainage and accelerated soil consolidation. This study presents a procedure for the design of vertical drains that significantly extends the previous technique proposed by the authors to include: (i) a linear reduction of lateral permeability in the smear zone, (ii) the effect of overlapping smear zones in a closely spaced drain network, and (iii) the gain in undrained shear strength due to consolidation. Design examples are provided for both single stage and multi-stage embankment construction demonstrating the convenient use of the proposed solutions in practical situations. Un système de drains verticaux avec pré-chargement en surcharge est un moyen efficace d’encourager le drainage radial et d’accélérer la consolidation du sol. Cette étude présente une procédure pour la conception de drains verticaux qui étend de façon significative la technique proposée précédemment par les auteurs pour inclure: (i) une réduction linéaire de la perméabilité linéaire dans la zone de souillure, (ii) l’effet de zones de souillure se chevauchant dans un réseau de drains situé dans espace restreint et (iii) le gain de résistance au cisaillement dû à la consolidation. Des exemples sont fournis pour des constructions de digues en une ou plusieurs étapes démontrant l’utilisation des solutions proposées pour des situations pratiques. DEWEY : 550 ISSN : 0008-3674 En ligne : http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=f [...]

Experimental investigation on effectiveness of a vertical drain under cyclic loads / Buddhima Indraratna in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 6 (Juin 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 6 (Juin 2009) . - pp. 835–839 Titre : Experimental investigation on effectiveness of a vertical drain under cyclic loads Type de document : texte imprimé Auteurs : Buddhima Indraratna, Auteur ; Anass Attya, Auteur ; Cholachat Rujikiatkamjorn, Auteur Année de publication : 2009 Article en page(s) : pp. 835–839 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Clays  Soil  consolidation  Drainage  Laboratory  tests  Repeated  loads  Cyclic  loads Résumé : This study examines the effectiveness of a prefabricated vertical drain (PVD) installed in reconstituted soft clay, where a large cyclic triaxial device was used to simulate repeated loading representing a rail track environment. The experimental data demonstrate that PVD successfully prevents excessive buildup of pore water pressure during cyclic loading, and that dissipation continues to occur after the load is removed. The findings of this study have direct relevance to rail track environments, e.g., in coastal Australia, where PVD installation beneath rail tracks constructed on low-lying estuarine soils has been recently introduced. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000006 [article] Experimental investigation on effectiveness of a vertical drain under cyclic loads [texte imprimé] / Buddhima Indraratna, Auteur ; Anass Attya, Auteur ; Cholachat Rujikiatkamjorn, Auteur . - 2009 . - pp. 835–839. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 6 (Juin 2009) . - pp. 835–839 Mots-clés : Clays  Soil  consolidation  Drainage  Laboratory  tests  Repeated  loads  Cyclic  loads Résumé : This study examines the effectiveness of a prefabricated vertical drain (PVD) installed in reconstituted soft clay, where a large cyclic triaxial device was used to simulate repeated loading representing a rail track environment. The experimental data demonstrate that PVD successfully prevents excessive buildup of pore water pressure during cyclic loading, and that dissipation continues to occur after the load is removed. The findings of this study have direct relevance to rail track environments, e.g., in coastal Australia, where PVD installation beneath rail tracks constructed on low-lying estuarine soils has been recently introduced. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000006

Laboratory and finite-element investigation of soil disturbance associated with the installation of mandrel-driven prefabricated vertical drains / Ali Ghandeharioon in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 3 (Mars 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 3 (Mars 2012) . - pp. 295-308 Titre : Laboratory and finite-element investigation of soil disturbance associated with the installation of mandrel-driven prefabricated vertical drains Type de document : texte imprimé Auteurs : Ali Ghandeharioon, Auteur ; Buddhima Indraratna, Auteur ; Cholachat Rujikiatkamjorn, Auteur Année de publication : 2012 Article en page(s) : pp. 295-308 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Mandrel-driven  prefabricated  vertical  drains  Laboratory  tests  Finite-element  method  Large-strain  frictional  contact  Smear  zone  Excess  pore  water  pressure Résumé : A series of large-scale laboratory experiments, along with numerical analyses, using the commercial finite-element software package, ABAQUS, were performed to investigate the installation of mandrel-driven prefabricated vertical drains (PVDs). The laboratory tests were conducted using a specially designed large-scale consolidometer and a novel mandrel-driving machine capable of working at installation rates in the range of usual practices. The finite-element simulations include coupled analyses with a large-strain formulation. Coulomb’s law of friction and the penalty method are incorporated into the numerical models. The variations of pore water pressure at different locations during installation of a PVD and withdrawal of the mandrel are presented. Good agreement is found between pore pressures measured in the laboratory and predicted numerically. Moreover, finite-element analyses reveal that when a mandrel is pushed into the soil deposit, the soil surrounding the mandrel moves radially and downwards. Laboratory tests for moisture content and the numerically predicted variations of plastic shear strain, normalized with the rigidity index of the soil, show that for a given type of soft soil subjected to a particular rate of mandrel installation, the size of the smear zone decreases as the in situ effective stresses increase. The finite-element model has been applied to a case history from the Second Bangkok International Airport in Thailand and proves that the model can be applied to field conditions. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i3/p295_s1?isAuthorized=no [article] Laboratory and finite-element investigation of soil disturbance associated with the installation of mandrel-driven prefabricated vertical drains [texte imprimé] / Ali Ghandeharioon, Auteur ; Buddhima Indraratna, Auteur ; Cholachat Rujikiatkamjorn, Auteur . - 2012 . - pp. 295-308. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 3 (Mars 2012) . - pp. 295-308 Mots-clés : Mandrel-driven  prefabricated  vertical  drains  Laboratory  tests  Finite-element  method  Large-strain  frictional  contact  Smear  zone  Excess  pore  water  pressure Résumé : A series of large-scale laboratory experiments, along with numerical analyses, using the commercial finite-element software package, ABAQUS, were performed to investigate the installation of mandrel-driven prefabricated vertical drains (PVDs). The laboratory tests were conducted using a specially designed large-scale consolidometer and a novel mandrel-driving machine capable of working at installation rates in the range of usual practices. The finite-element simulations include coupled analyses with a large-strain formulation. Coulomb’s law of friction and the penalty method are incorporated into the numerical models. The variations of pore water pressure at different locations during installation of a PVD and withdrawal of the mandrel are presented. Good agreement is found between pore pressures measured in the laboratory and predicted numerically. Moreover, finite-element analyses reveal that when a mandrel is pushed into the soil deposit, the soil surrounding the mandrel moves radially and downwards. Laboratory tests for moisture content and the numerically predicted variations of plastic shear strain, normalized with the rigidity index of the soil, show that for a given type of soft soil subjected to a particular rate of mandrel installation, the size of the smear zone decreases as the in situ effective stresses increase. The finite-element model has been applied to a case history from the Second Bangkok International Airport in Thailand and proves that the model can be applied to field conditions. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v138/i3/p295_s1?isAuthorized=no

Numerical solution of stone column–improved soft soil considering arching, clogging, and smear effects / Buddhima Indraratna in Journal of geotechnical and geoenvironmental engineering, Vol. 139 N° 3 (Mars 2013) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 377-394 Titre : Numerical solution of stone column–improved soft soil considering arching, clogging, and smear effects Type de document : texte imprimé Auteurs : Buddhima Indraratna, Auteur ; Sudip Basack, Auteur ; Cholachat Rujikiatkamjorn, Auteur Année de publication : 2013 Article en page(s) : pp. 377-394 Note générale : geotechnique Langues : Anglais (eng) Mots-clés : finite  difference  method;  foundation  settlement;  numerical  models;  soft  soils;  soil  permeability;  stone  columns;  arches Résumé : Improvement of soft clay deposits by the installation of stone columns is one of the most popular techniques followed worldwide. The stone columns not only act as reinforcing material increasing the overall strength and stiffness of the compressible soft soil, but they also promote consolidation through effective drainage. The analytical and numerical solutions available for ascertaining the response of column-reinforced soil have been developed on the basis of the equal strain hypothesis. For typical surcharge (embankment) loading, the free strain analysis appears to give more realistic results comparable to field data. The paper presents a novel numerical model (finite-difference method) to analyze the response of stone column–reinforced soft soil under embankment loading, adopting the free strain approach and considering both arching and clogging effects. Apart from predicting the dissipation of excess pore water pressure and the resulting consolidation settlement with time, the load transfer mechanism and the extent of ground improvement are some of the salient features captured by the proposed model. The proposed model is validated by comparing with existing models and field data, which indicate the suitability and accuracy of the solutions. The proposed model is also applied successfully to selected case studies. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000789 [article] Numerical solution of stone column–improved soft soil considering arching, clogging, and smear effects [texte imprimé] / Buddhima Indraratna, Auteur ; Sudip Basack, Auteur ; Cholachat Rujikiatkamjorn, Auteur . - 2013 . - pp. 377-394. geotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 377-394 Mots-clés : finite  difference  method;  foundation  settlement;  numerical  models;  soft  soils;  soil  permeability;  stone  columns;  arches Résumé : Improvement of soft clay deposits by the installation of stone columns is one of the most popular techniques followed worldwide. The stone columns not only act as reinforcing material increasing the overall strength and stiffness of the compressible soft soil, but they also promote consolidation through effective drainage. The analytical and numerical solutions available for ascertaining the response of column-reinforced soil have been developed on the basis of the equal strain hypothesis. For typical surcharge (embankment) loading, the free strain analysis appears to give more realistic results comparable to field data. The paper presents a novel numerical model (finite-difference method) to analyze the response of stone column–reinforced soft soil under embankment loading, adopting the free strain approach and considering both arching and clogging effects. Apart from predicting the dissipation of excess pore water pressure and the resulting consolidation settlement with time, the load transfer mechanism and the extent of ground improvement are some of the salient features captured by the proposed model. The proposed model is validated by comparing with existing models and field data, which indicate the suitability and accuracy of the solutions. The proposed model is also applied successfully to selected case studies. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000789

Performance and prediction of vacuum combined surcharge consolidation at port of brisbane / Buddhima Indraratna in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 11 (Novembre 2011) 

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