Documents disponibles écrits par cet auteur

Coupled-consolidation modeling of a pile in consolidating ground / W. M. Yan in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 7 (Juillet 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 7 (Juillet 2012) . - pp. 789–798 Titre : Coupled-consolidation modeling of a pile in consolidating ground Type de document : texte imprimé Auteurs : W. M. Yan, Auteur ; T. K. Sun, Auteur ; L. G. Tham, Auteur Année de publication : 2012 Article en page(s) : pp. 789–798 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Negative  skin  friction  Dragload  Pile-soil  interface  Consolidation Résumé : When a pile is embedded in a consolidating ground (e.g., newly reclaimed land), soil may settle more than the pile, thus generating negative skin friction along the pile shaft. This negative friction induces additional axial load to the pile (dragload) and pulls the pile further downward (downdrag). In this paper, the problem is investigated numerically with the finite-element package ABAQUS. It was found that the package defaults an interface model that models the mobilized interface strength in a way that the effect of water pressure was overlooked. Therefore, a modified numerical algorithm is proposed in this study. It amends the model by correctly bringing pore water pressure into the calculation steps. which properly simulates the effective stress-dependent nature of the shear strength at the soil-pile interface. The algorithm is then verified by a self-contained simple to understand simulation. A case history of two piles (one of them coated with bitumen) embedded in a consolidating soft ground is then back analyzed with the proposed algorithm. Fully coupled consolidation and geometric nonlinearity are also considered in the analyses. The transient response of the problem is investigated, including the development of dragload, downdrag, and neutral plane with time. The simulation generally fits well with the field measurements. Parametric studies of the effects of pile head loading reveal that the position of the neutral plane depends not only on the magnitude of the applied pile head loading, but is also affected when the load is applied with respect to the consolidation process. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000651 [article] Coupled-consolidation modeling of a pile in consolidating ground [texte imprimé] / W. M. Yan, Auteur ; T. K. Sun, Auteur ; L. G. Tham, Auteur . - 2012 . - pp. 789–798. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 7 (Juillet 2012) . - pp. 789–798 Mots-clés : Negative  skin  friction  Dragload  Pile-soil  interface  Consolidation Résumé : When a pile is embedded in a consolidating ground (e.g., newly reclaimed land), soil may settle more than the pile, thus generating negative skin friction along the pile shaft. This negative friction induces additional axial load to the pile (dragload) and pulls the pile further downward (downdrag). In this paper, the problem is investigated numerically with the finite-element package ABAQUS. It was found that the package defaults an interface model that models the mobilized interface strength in a way that the effect of water pressure was overlooked. Therefore, a modified numerical algorithm is proposed in this study. It amends the model by correctly bringing pore water pressure into the calculation steps. which properly simulates the effective stress-dependent nature of the shear strength at the soil-pile interface. The algorithm is then verified by a self-contained simple to understand simulation. A case history of two piles (one of them coated with bitumen) embedded in a consolidating soft ground is then back analyzed with the proposed algorithm. Fully coupled consolidation and geometric nonlinearity are also considered in the analyses. The transient response of the problem is investigated, including the development of dragload, downdrag, and neutral plane with time. The simulation generally fits well with the field measurements. Parametric studies of the effects of pile head loading reveal that the position of the neutral plane depends not only on the magnitude of the applied pile head loading, but is also affected when the load is applied with respect to the consolidation process. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000651

Loose fill slope stabilization with soil nails / J. Li in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°3 (Mars 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°3 (Mars 2008) . - pp. 277–288 Titre : Loose fill slope stabilization with soil nails : full-scale test Type de document : texte imprimé Auteurs : J. Li, Auteur ; L. G. Tham, Auteur ; S. M. Junaideen, Auteur Année de publication : 2008 Article en page(s) : pp. 277–288 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Field  tests  Slope  stability  Fills  Rainfall Résumé : Soil nailing is commonly used for stabilizing cut slopes and retaining structures. The technique is, however, seldom used in stabilizing old loose fill slopes that were not constructed to the current standards. There is a concern that soil-nailed loose fill slopes may not render safety during heavy rainstorms. Little work has been carried out to investigate the behavior of soil-nailed loose fill slopes. This paper presents a comprehensive field test on a loose fill slope that was constructed by end tipping without any compaction—in the same way old fill slopes were formed. The slope was 4.75m high, 9m wide, and 33deg to the horizontal. Two rows of five grouted nails were installed at a grid of 1.5m×1.5m at an inclination of 20deg from the horizontal. A surface grillage was used to connect the six nails in the middle of the grid. Performance of the nailed slope was monitored with various instruments for about six months until the slope was tested to fail by surcharging and wetting. The overall results show that soil nailing with a surface grillage is a potentially effective way to enhance the stability of old fill slopes. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A3%2827 [...] [article] Loose fill slope stabilization with soil nails : full-scale test [texte imprimé] / J. Li, Auteur ; L. G. Tham, Auteur ; S. M. Junaideen, Auteur . - 2008 . - pp. 277–288. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°3 (Mars 2008) . - pp. 277–288 Mots-clés : Field  tests  Slope  stability  Fills  Rainfall Résumé : Soil nailing is commonly used for stabilizing cut slopes and retaining structures. The technique is, however, seldom used in stabilizing old loose fill slopes that were not constructed to the current standards. There is a concern that soil-nailed loose fill slopes may not render safety during heavy rainstorms. Little work has been carried out to investigate the behavior of soil-nailed loose fill slopes. This paper presents a comprehensive field test on a loose fill slope that was constructed by end tipping without any compaction—in the same way old fill slopes were formed. The slope was 4.75m high, 9m wide, and 33deg to the horizontal. Two rows of five grouted nails were installed at a grid of 1.5m×1.5m at an inclination of 20deg from the horizontal. A surface grillage was used to connect the six nails in the middle of the grid. Performance of the nailed slope was monitored with various instruments for about six months until the slope was tested to fail by surcharging and wetting. The overall results show that soil nailing with a surface grillage is a potentially effective way to enhance the stability of old fill slopes. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A3%2827 [...]