Documents disponibles écrits par cet auteur

Centrifuge modeling and mitigation of manhole uplift due to liquefaction / Gi-Chun Kang 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. 458-469 Titre : Centrifuge modeling and mitigation of manhole uplift due to liquefaction Type de document : texte imprimé Auteurs : Gi-Chun Kang, Auteur ; Tetsuo Tobita, Auteur ; Susumu Iai, Auteur Année de publication : 2013 Article en page(s) : pp. 458-469 Note générale : geotechnique Langues : Anglais (eng) Mots-clés : centrifuge  models;  soil  liquefaction;  earthquakes;  manholes;  uplifting Résumé : Because low-compacted trench backfill around a manhole is normally liquefiable, the manhole could suffer uplift damage associated with soil liquefaction during a strong earthquake. In this study, 22 dynamic centrifuge models were tested to investigate the response of a buried manhole subjected to a dynamic load. The models were tested under 20g, and a substitute pore fluid was used to avoid the scaling law conflict between the dynamic and diffusion processes. It was found that excess pore water pressure is one of the contributing factors to the magnitude of the manhole uplift. Using this result, new mitigation methods against the uplift in liquefied ground were developed. Their effectiveness was also examined through the tests. A model manhole mitigated with the proposed methods was tested alongside regular model manhole. From the test results, the magnitude of manhole uplifts with the mitigation methods decreased as buildup of the excess pore water pressure was restrained in high-compacted backfill or excess pore water was dissipated into the manhole during strong shaking. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000769 [article] Centrifuge modeling and mitigation of manhole uplift due to liquefaction [texte imprimé] / Gi-Chun Kang, Auteur ; Tetsuo Tobita, Auteur ; Susumu Iai, Auteur . - 2013 . - pp. 458-469. geotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 458-469 Mots-clés : centrifuge  models;  soil  liquefaction;  earthquakes;  manholes;  uplifting Résumé : Because low-compacted trench backfill around a manhole is normally liquefiable, the manhole could suffer uplift damage associated with soil liquefaction during a strong earthquake. In this study, 22 dynamic centrifuge models were tested to investigate the response of a buried manhole subjected to a dynamic load. The models were tested under 20g, and a substitute pore fluid was used to avoid the scaling law conflict between the dynamic and diffusion processes. It was found that excess pore water pressure is one of the contributing factors to the magnitude of the manhole uplift. Using this result, new mitigation methods against the uplift in liquefied ground were developed. Their effectiveness was also examined through the tests. A model manhole mitigated with the proposed methods was tested alongside regular model manhole. From the test results, the magnitude of manhole uplifts with the mitigation methods decreased as buildup of the excess pore water pressure was restrained in high-compacted backfill or excess pore water was dissipated into the manhole during strong shaking. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000769

Estimation of liquefaction-induced manhole uplift displacements and trench-backfill settlements / Tetsuo Tobita in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 4 (Avril 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 491–499 Titre : Estimation of liquefaction-induced manhole uplift displacements and trench-backfill settlements Type de document : texte imprimé Auteurs : Tetsuo Tobita, Auteur ; Gi-Chun Kang, Auteur ; Susumu Iai, Auteur Année de publication : 2012 Article en page(s) : pp. 491–499 Note générale : Géologie appliquée Langues : Anglais (eng) Mots-clés : Manhole  Earthquakes  Liquefaction  Centrifuge  modeling  Safety  factor Résumé : A simple method to predict the uplift displacement of a manhole and trench-backfill settlement due to liquefaction is proposed. The conventional equilibrium of vertical forces acting on a manhole is solely a function of such forces acting and is incapable of predicting the uplift displacement. In this paper, the proposed method adds variables including the uplift displacement, Δf, and settlements of backfill, Δs, under the condition that the volume of an uplifted portion of a manhole is equal to a settled volume of a trench-backfill. To date, the method is verified through comparison with the results of 1-G and centrifuge model tests. A new safety factor, which takes into account the amount of manhole uplift and backfill settlement, is also derived. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000615 [article] Estimation of liquefaction-induced manhole uplift displacements and trench-backfill settlements [texte imprimé] / Tetsuo Tobita, Auteur ; Gi-Chun Kang, Auteur ; Susumu Iai, Auteur . - 2012 . - pp. 491–499. Géologie appliquée Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 491–499 Mots-clés : Manhole  Earthquakes  Liquefaction  Centrifuge  modeling  Safety  factor Résumé : A simple method to predict the uplift displacement of a manhole and trench-backfill settlement due to liquefaction is proposed. The conventional equilibrium of vertical forces acting on a manhole is solely a function of such forces acting and is incapable of predicting the uplift displacement. In this paper, the proposed method adds variables including the uplift displacement, Δf, and settlements of backfill, Δs, under the condition that the volume of an uplifted portion of a manhole is equal to a settled volume of a trench-backfill. To date, the method is verified through comparison with the results of 1-G and centrifuge model tests. A new safety factor, which takes into account the amount of manhole uplift and backfill settlement, is also derived. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000615