Documents disponibles écrits par cet auteur

Estimation of axial load capacity for bored tapered piles using CPT results in sand / Junhwan Lee in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 9 (Septembre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 9 (Septembre 2009) . - pp. 1285–1294 Titre : Estimation of axial load capacity for bored tapered piles using CPT results in sand Type de document : texte imprimé Auteurs : Junhwan Lee, Auteur ; Kyuho Paik, Auteur ; Deahong Kim, Auteur Année de publication : 2009 Article en page(s) : pp. 1285–1294 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : PilesLoad  bearing  capacityCalibrationCone  penetration  testsSandSettlementAxial  loads Résumé : Tapered piles in comparison to cylindrical piles can be beneficial in terms of the load capacity. In this paper, estimation of the load capacity for tapered piles using cone penetration test (CPT) resistance was investigated. Fourteen calibration chamber load tests using different pile types and six CPTs were conducted under various soil conditions. From the calibration chamber test results, the total, base, and shaft load capacities were analyzed in terms of soil conditions and taper angle. To evaluate CPT-based load capacity of tapered piles, normalized base and shaft resistances were obtained from normalized unit load-settlement curves. Based on the normalized base and shaft resistances, design equations that can be used to evaluate the base and shaft resistances of tapered piles were proposed. The proposed method is valid for sands of medium to dense conditions, while it may result in unconservative predictions for loose sands. To check the accuracy of the proposed method, field load tests using both cylindrical and tapered piles were conducted and compared with the predictions using the proposed method. A simplified approach using an equivalent cylindrical pile was also investigated and compared. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000036 [article] Estimation of axial load capacity for bored tapered piles using CPT results in sand [texte imprimé] / Junhwan Lee, Auteur ; Kyuho Paik, Auteur ; Deahong Kim, Auteur . - 2009 . - pp. 1285–1294. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 9 (Septembre 2009) . - pp. 1285–1294 Mots-clés : PilesLoad  bearing  capacityCalibrationCone  penetration  testsSandSettlementAxial  loads Résumé : Tapered piles in comparison to cylindrical piles can be beneficial in terms of the load capacity. In this paper, estimation of the load capacity for tapered piles using cone penetration test (CPT) resistance was investigated. Fourteen calibration chamber load tests using different pile types and six CPTs were conducted under various soil conditions. From the calibration chamber test results, the total, base, and shaft load capacities were analyzed in terms of soil conditions and taper angle. To evaluate CPT-based load capacity of tapered piles, normalized base and shaft resistances were obtained from normalized unit load-settlement curves. Based on the normalized base and shaft resistances, design equations that can be used to evaluate the base and shaft resistances of tapered piles were proposed. The proposed method is valid for sands of medium to dense conditions, while it may result in unconservative predictions for loose sands. To check the accuracy of the proposed method, field load tests using both cylindrical and tapered piles were conducted and compared with the predictions using the proposed method. A simplified approach using an equivalent cylindrical pile was also investigated and compared. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000036

Estimation of lateral load capacity of rigid short piles in sands using CPT results / Junhwan Lee 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. 48-56 Titre : Estimation of lateral load capacity of rigid short piles in sands using CPT results Type de document : texte imprimé Auteurs : Junhwan Lee, Auteur ; Minki Kim, Auteur ; Doohyun Kyung, Auteur Article en page(s) : pp. 48-56 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Piles  Lateral  load  capacity  Lateral  soil  resistance  Cone  penetration  test  Sands  Calibration  Chamber  tests Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Conventional methods for the estimation of the ultimate lateral pile load capacity are typically based on certain expressions of the lateral soil resistance pu and assumed distributions of the lateral soil pressure mobilized along the pile embedded depth. When soils are nonhomogenous, however, the application of conventional methods represents significant difficulties due to the nonlinear and irregular variation of pu with depth. In this study, a cone penetration test (CPT)-based methodology for the estimation of the ultimate lateral pile load capacity Hu was proposed, which can take full account of entire soil profile through the CPT cone resistance qc. A normalized correlation between qc and pu was proposed with correlation parameters corresponding to different existing methods. In order to validate the proposed CPT-based methodology, case examples of laterally loaded piles in various soil conditions were prepared and used to compare values of Hu from original and proposed methods. Calibration chamber test results were adopted to verify the proposed methodology. Field lateral pile load tests were performed to further verify the proposed CPT-based method for field conditions. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...] [article] Estimation of lateral load capacity of rigid short piles in sands using CPT results [texte imprimé] / Junhwan Lee, Auteur ; Minki Kim, Auteur ; Doohyun Kyung, Auteur . - pp. 48-56. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 1 (Janvier 2010) . - pp. 48-56 Mots-clés : Piles  Lateral  load  capacity  Lateral  soil  resistance  Cone  penetration  test  Sands  Calibration  Chamber  tests Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Conventional methods for the estimation of the ultimate lateral pile load capacity are typically based on certain expressions of the lateral soil resistance pu and assumed distributions of the lateral soil pressure mobilized along the pile embedded depth. When soils are nonhomogenous, however, the application of conventional methods represents significant difficulties due to the nonlinear and irregular variation of pu with depth. In this study, a cone penetration test (CPT)-based methodology for the estimation of the ultimate lateral pile load capacity Hu was proposed, which can take full account of entire soil profile through the CPT cone resistance qc. A normalized correlation between qc and pu was proposed with correlation parameters corresponding to different existing methods. In order to validate the proposed CPT-based methodology, case examples of laterally loaded piles in various soil conditions were prepared and used to compare values of Hu from original and proposed methods. Calibration chamber test results were adopted to verify the proposed methodology. Field lateral pile load tests were performed to further verify the proposed CPT-based method for field conditions. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...]

Penetrometer-based assessment of spudcan penetration resistance / Junhwan Lee in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 6 (Juin 2011) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 6 (Juin 2011) . - pp. 587-596 Titre : Penetrometer-based assessment of spudcan penetration resistance Type de document : texte imprimé Auteurs : Junhwan Lee, Auteur ; Mark F. Randolph, Auteur Année de publication : 2011 Article en page(s) : pp. 587-596 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Spudcan  Jack-up  rigs  Penetration  resistance  TT-bar  tests  Cone  penetration  tests  Penetration  rate  Partial  drainage  conditions Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Estimation of spudcan penetration resistance is an important design step to guarantee the stability and functionality of offshore mobile jack-up units. Dependence on in situ penetrometer test data to evaluate the stratigraphy and resulting spudcan capacity profile has been increased. However, this becomes difficult in intermediate soil types in which the degree of consolidation during penetration falls between the extremes of fully drained or fully undrained. In this study, a penetrometer-based methodology utilizing results from cone and T-bar penetration tests is developed. Three main steps are involved, comprising estimation of the relative penetration resistance of spudcan and cone or T-bar penetrometer under fully drained and fully undrained conditions, and then quantifying the effect of the different normalized penetration rates for spudcan and penetrometer. Values of the various correlation parameters for the proposed model are evaluated. The validity and accuracy of the proposed methodology are evaluated through case studies from centrifuge tests in clay and a field example of spudcan installation in interbedded carbonate silts and sands. The comparisons confirm the potential of the proposed methodology for interpretation of penetrometer tests and application to the prediction of foundation performance. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i6/p587_s1?isAuthorized=no [article] Penetrometer-based assessment of spudcan penetration resistance [texte imprimé] / Junhwan Lee, Auteur ; Mark F. Randolph, Auteur . - 2011 . - pp. 587-596. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 6 (Juin 2011) . - pp. 587-596 Mots-clés : Spudcan  Jack-up  rigs  Penetration  resistance  TT-bar  tests  Cone  penetration  tests  Penetration  rate  Partial  drainage  conditions Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Estimation of spudcan penetration resistance is an important design step to guarantee the stability and functionality of offshore mobile jack-up units. Dependence on in situ penetrometer test data to evaluate the stratigraphy and resulting spudcan capacity profile has been increased. However, this becomes difficult in intermediate soil types in which the degree of consolidation during penetration falls between the extremes of fully drained or fully undrained. In this study, a penetrometer-based methodology utilizing results from cone and T-bar penetration tests is developed. Three main steps are involved, comprising estimation of the relative penetration resistance of spudcan and cone or T-bar penetrometer under fully drained and fully undrained conditions, and then quantifying the effect of the different normalized penetration rates for spudcan and penetrometer. Values of the various correlation parameters for the proposed model are evaluated. The validity and accuracy of the proposed methodology are evaluated through case studies from centrifuge tests in clay and a field example of spudcan installation in interbedded carbonate silts and sands. The comparisons confirm the potential of the proposed methodology for interpretation of penetrometer tests and application to the prediction of foundation performance. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i6/p587_s1?isAuthorized=no

Strain influence diagrams for settlement estimation of both isolated and multiple footings in sand / Junhwan Lee in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°4 (Avril 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°4 (Avril 2008) . - pp. 417–427 Titre : Strain influence diagrams for settlement estimation of both isolated and multiple footings in sand Type de document : texte imprimé Auteurs : Junhwan Lee, Auteur ; Jongwan Eun, Auteur ; Monica Prezzi, Auteur Année de publication : 2008 Article en page(s) : pp. 417–427 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Footings  Settlement  Strains  Finite  element  method  Sand Résumé : Most of the existing methods for estimating settlements of footings in sand have been developed for either isolated square footings or for strip footings. The literature contains limited information on settlement analysis of rectangular footings, and, as a result, there is no way to accurately account for the effect of the footing length-to-width ratio on settlement. Additionally, no practical method exists for considering the interaction between neighboring footings in settlement estimates. In this paper, we use Schmertmann’s framework to propose a method of settlement estimation that takes full account of both the footing length-to-width ratio and the proximity of neighboring footings. Three-dimensional nonlinear finite element analyses were performed for various multiple footing configurations. Plate load tests were performed in sands using both a single plate and two plates separated by various distances. The numerical and experimental results indicate that the shape of the footing (expressed through its length-to-width ratio) and the proximity of neighboring footings affect two parameters of the strain influence diagram (which is the basis for the settlement estimation method): the depth to the peak influence factor Izp and the depth of the strain influence zone. We propose new strain influence diagrams for estimation of settlement under these more general conditions. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A4%2841 [...] [article] Strain influence diagrams for settlement estimation of both isolated and multiple footings in sand [texte imprimé] / Junhwan Lee, Auteur ; Jongwan Eun, Auteur ; Monica Prezzi, Auteur . - 2008 . - pp. 417–427. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°4 (Avril 2008) . - pp. 417–427 Mots-clés : Footings  Settlement  Strains  Finite  element  method  Sand Résumé : Most of the existing methods for estimating settlements of footings in sand have been developed for either isolated square footings or for strip footings. The literature contains limited information on settlement analysis of rectangular footings, and, as a result, there is no way to accurately account for the effect of the footing length-to-width ratio on settlement. Additionally, no practical method exists for considering the interaction between neighboring footings in settlement estimates. In this paper, we use Schmertmann’s framework to propose a method of settlement estimation that takes full account of both the footing length-to-width ratio and the proximity of neighboring footings. Three-dimensional nonlinear finite element analyses were performed for various multiple footing configurations. Plate load tests were performed in sands using both a single plate and two plates separated by various distances. The numerical and experimental results indicate that the shape of the footing (expressed through its length-to-width ratio) and the proximity of neighboring footings affect two parameters of the strain influence diagram (which is the basis for the settlement estimation method): the depth to the peak influence factor Izp and the depth of the strain influence zone. We propose new strain influence diagrams for estimation of settlement under these more general conditions. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A4%2841 [...]