Documents disponibles écrits par cet auteur

Fully probabilistic framework for evaluating excavation-induced damage potential of adjacent buildings / C. Hsein Juang in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 2 (Fevrier 2011) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 2 (Fevrier 2011) . - pp. 130-139 Titre : Fully probabilistic framework for evaluating excavation-induced damage potential of adjacent buildings Type de document : texte imprimé Auteurs : C. Hsein Juang, Auteur ; Matt Schuster, Auteur ; Chang-Yu Ou, Auteur Année de publication : 2011 Article en page(s) : pp. 130-139 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Reliability  Braced  excavation  Ground  settlement  Wall  deflection  Building  damage Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents a framework for a fully probabilistic analysis of the potential for damage to buildings adjacent to an excavation. Herein, the damage potential index (DPI), which is a function of angular distortion and lateral strain, is used to assess building damage potential. A serviceability limit state is established in which the resistance is expressed in terms of the “limiting” DPI, and the load is represented by the “applied” DPI. In this context, damage to the building adjacent to an excavation is said to occur deterministically if the applied DPI is greater than the limiting DPI. For the fully probabilistic analysis, both parameter and model uncertainties of the limiting and applied DPIs are first characterized. The analysis framework is then presented and demonstrated with a case history. Finally, sensitivity analysis is performed to identify the factors to which the probability of damage is most sensitive and to analyze the effect of various assumptions of the input parameters on the computed probability of building damage. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i2/p130_s1?isAuthorized=no [article] Fully probabilistic framework for evaluating excavation-induced damage potential of adjacent buildings [texte imprimé] / C. Hsein Juang, Auteur ; Matt Schuster, Auteur ; Chang-Yu Ou, Auteur . - 2011 . - pp. 130-139. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 2 (Fevrier 2011) . - pp. 130-139 Mots-clés : Reliability  Braced  excavation  Ground  settlement  Wall  deflection  Building  damage Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents a framework for a fully probabilistic analysis of the potential for damage to buildings adjacent to an excavation. Herein, the damage potential index (DPI), which is a function of angular distortion and lateral strain, is used to assess building damage potential. A serviceability limit state is established in which the resistance is expressed in terms of the “limiting” DPI, and the load is represented by the “applied” DPI. In this context, damage to the building adjacent to an excavation is said to occur deterministically if the applied DPI is greater than the limiting DPI. For the fully probabilistic analysis, both parameter and model uncertainties of the limiting and applied DPIs are first characterized. The analysis framework is then presented and demonstrated with a case history. Finally, sensitivity analysis is performed to identify the factors to which the probability of damage is most sensitive and to analyze the effect of various assumptions of the input parameters on the computed probability of building damage. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i2/p130_s1?isAuthorized=no

Performance of excavations with vross walls / Chang-Yu Ou in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 1 (Janvier 2011) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 1 (Janvier 2011) . - pp. 94-104 Titre : Performance of excavations with vross walls Type de document : texte imprimé Auteurs : Chang-Yu Ou, Auteur ; Pio-Go Hsieh, Auteur ; Yi-Lang Lin, Auteur Année de publication : 2011 Article en page(s) : pp. 94-104 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Deep  excavation  Cross  wall  Wall  deflection  Surface  settlement  Numerical  analysis Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents the performance of an excavation with cross walls based on field observations and numerical analysis results. A small strain constitutive model was used in the analysis. By comparing the movements of the real case with the same case but without cross walls installed, the effectiveness of cross walls was thus evaluated. Results indicate that the movements in the case history were substantially reduced by the installation of cross walls. The maximum wall deflection and ground settlement at a place where the cross wall was installed was reduced by about 75 and 82%, respectively. The movements near the diaphragm wall or cross wall corner were relatively small, compared with those far away from the corner. The diaphragm wall still had some deflection at the sections where cross walls were installed and the amount of deflection was close to that from linear elastic analysis. It is justified that slime between cross walls and diaphragm walls during trench excavation was fully cleaned. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i1/p94_s1?isAuthorized=no [article] Performance of excavations with vross walls [texte imprimé] / Chang-Yu Ou, Auteur ; Pio-Go Hsieh, Auteur ; Yi-Lang Lin, Auteur . - 2011 . - pp. 94-104. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 1 (Janvier 2011) . - pp. 94-104 Mots-clés : Deep  excavation  Cross  wall  Wall  deflection  Surface  settlement  Numerical  analysis Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents the performance of an excavation with cross walls based on field observations and numerical analysis results. A small strain constitutive model was used in the analysis. By comparing the movements of the real case with the same case but without cross walls installed, the effectiveness of cross walls was thus evaluated. Results indicate that the movements in the case history were substantially reduced by the installation of cross walls. The maximum wall deflection and ground settlement at a place where the cross wall was installed was reduced by about 75 and 82%, respectively. The movements near the diaphragm wall or cross wall corner were relatively small, compared with those far away from the corner. The diaphragm wall still had some deflection at the sections where cross walls were installed and the amount of deflection was close to that from linear elastic analysis. It is justified that slime between cross walls and diaphragm walls during trench excavation was fully cleaned. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i1/p94_s1?isAuthorized=no

Reliability-based design for basal heave stability of deep / Shih-Hsuan Wu in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 5 (Mai 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 5 (Mai 2012) . - pp. 594–603 Titre : Reliability-based design for basal heave stability of deep : Excavations in spatially varying soils Type de document : texte imprimé Auteurs : Shih-Hsuan Wu, Auteur ; Chang-Yu Ou, Auteur ; Jianye Ching, Auteur Année de publication : 2012 Article en page(s) : pp. 594–603 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Reliability-based  design  Spatial  variability  Basal  heave  Deep  excavation Résumé : Spatial variability of soil undrained shear strength is usually not rigorously considered in the design of basal heave for deep excavations. In this study, the slip circle method is employed to investigate how the required safety-factor against basal heave was affected by spatial variability in the context of reliability-based design. The nonstationary random field model is adopted to model spatial variability of undrained shear strength. Results show that the required safety-factor obtained with the consideration of spatial variability is much smaller than that without the consideration. Parametric studies show that the vertical scale of fluctuation has a significant influence on the required safety-factor: the longer the scale of fluctuation, the larger the required safety-factor. For target failure probabilities of 0.01 and 0.001, the corresponding required safety factors are in the ranges of 1.4–1.9 and 1.6–2.4, respectively, for the average value of vertical scale of fluctuation of 2.5 m. Design charts are provided for the ease of implementation, and an example of reliability-based design for basal stability is given for demonstration. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000626 [article] Reliability-based design for basal heave stability of deep : Excavations in spatially varying soils [texte imprimé] / Shih-Hsuan Wu, Auteur ; Chang-Yu Ou, Auteur ; Jianye Ching, Auteur . - 2012 . - pp. 594–603. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 5 (Mai 2012) . - pp. 594–603 Mots-clés : Reliability-based  design  Spatial  variability  Basal  heave  Deep  excavation Résumé : Spatial variability of soil undrained shear strength is usually not rigorously considered in the design of basal heave for deep excavations. In this study, the slip circle method is employed to investigate how the required safety-factor against basal heave was affected by spatial variability in the context of reliability-based design. The nonstationary random field model is adopted to model spatial variability of undrained shear strength. Results show that the required safety-factor obtained with the consideration of spatial variability is much smaller than that without the consideration. Parametric studies show that the vertical scale of fluctuation has a significant influence on the required safety-factor: the longer the scale of fluctuation, the larger the required safety-factor. For target failure probabilities of 0.01 and 0.001, the corresponding required safety factors are in the ranges of 1.4–1.9 and 1.6–2.4, respectively, for the average value of vertical scale of fluctuation of 2.5 m. Design charts are provided for the ease of implementation, and an example of reliability-based design for basal stability is given for demonstration. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000626

Soil improvement using electroosmosis with the injection of chemical solutions / Chang-Yu Ou in Canadian geotechnical journal, Vol. 46 N° 6 (Juin 2009) 

Public ISBD [article]  in Canadian geotechnical journal > Vol. 46 N° 6 (Juin 2009) . - pp. 727–733 Titre : Soil improvement using electroosmosis with the injection of chemical solutions : field tests Type de document : texte imprimé Auteurs : Chang-Yu Ou, Auteur ; Shao-Chi Chien, Auteur ; Hsuan-Hsiang Chang, Auteur Article en page(s) : pp. 727–733 Note générale : Sciences de la Terre Langues : Anglais (eng) Mots-clés : Ground  improvement  Electroosmotic  chemical  treatment  Undrained  shear  strength  Amélioration  du  sol  Traitement  chimique  d’électro-osmose  Résistance  au  cisaillement  non  drainé Index. décimale : 550 Sciences auxiliaires de la géologie. Résumé : Previous laboratory studies have shown that the injection of a calcium chloride solution followed by the injection of a sodium silicate solution during electroosmosis is effective in strengthening soft silty clay. Very stiff cemented soil near the anodes is formed after the treatment. This paper presents the effectiveness of the process in the field. Nine electrodes were installed using two grid arrangements with electrode spacings of 2.0 m × 2.5 m and 2.0 m × 5.0 m. The test procedure is similar to those employed in the laboratory. Test results show that the soil surrounding the anodes (within a diameter of 50–60 cm) became very stiff and cemented due to the effect of cementation between the two chemical solutions and soil particles under the electric field. Except for the areas of stiff cemented soil, the undrained shear strength of the soil between electrodes was increased substantially. Polarity reversal after normal polarity did not produce favorable improvement effects in terms of undrained shear strength of the soil and treatment time. Des études en laboratoire dans le passé ont démontré que l’injection d’une solution de chlorure de calcium suivie d’une injection d’une solution de silicate de sodium durant l’électro-osmose est efficace pour augmenter la résistance d’une argile silteuse molle. Après le traitement, un sol cimenté très dur s’est formé près des anodes. Cet article présente l’efficacité de ce processus sur le terrain. Neuf électrodes ont été installées en deux arrangements en forme de grille de 2 m × 2,5 m et 2 m × 5 m. La procédure d’essais était semblable à celle utilisée en laboratoire. Les résultats de ces essais ont montré qu’un sol cimenté très dur est formé, avec un diamètre de 50 à 60 cm autour des anodes, suite à un effet de cimentation entre les deux solutions chimiques et les particules de sol soumises à un champ électrique. La résistance au cisaillement en condition non drainée du sol entre les électrodes a augmenté considérablement, à l’exception des zones de sol cimenté très dur. L’inversion de la polarité après l’application de la polarité normale n’a pas produit d’amélioration en termes de résistance au cisaillement non drainé du sol, et de temps de traitement. DEWEY : 550 ISSN : 0008-3674 En ligne : http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=f [...] [article] Soil improvement using electroosmosis with the injection of chemical solutions : field tests [texte imprimé] / Chang-Yu Ou, Auteur ; Shao-Chi Chien, Auteur ; Hsuan-Hsiang Chang, Auteur . - pp. 727–733. Sciences de la Terre Langues : Anglais (eng) in Canadian geotechnical journal > Vol. 46 N° 6 (Juin 2009) . - pp. 727–733 Mots-clés : Ground  improvement  Electroosmotic  chemical  treatment  Undrained  shear  strength  Amélioration  du  sol  Traitement  chimique  d’électro-osmose  Résistance  au  cisaillement  non  drainé Index. décimale : 550 Sciences auxiliaires de la géologie. Résumé : Previous laboratory studies have shown that the injection of a calcium chloride solution followed by the injection of a sodium silicate solution during electroosmosis is effective in strengthening soft silty clay. Very stiff cemented soil near the anodes is formed after the treatment. This paper presents the effectiveness of the process in the field. Nine electrodes were installed using two grid arrangements with electrode spacings of 2.0 m × 2.5 m and 2.0 m × 5.0 m. The test procedure is similar to those employed in the laboratory. Test results show that the soil surrounding the anodes (within a diameter of 50–60 cm) became very stiff and cemented due to the effect of cementation between the two chemical solutions and soil particles under the electric field. Except for the areas of stiff cemented soil, the undrained shear strength of the soil between electrodes was increased substantially. Polarity reversal after normal polarity did not produce favorable improvement effects in terms of undrained shear strength of the soil and treatment time. Des études en laboratoire dans le passé ont démontré que l’injection d’une solution de chlorure de calcium suivie d’une injection d’une solution de silicate de sodium durant l’électro-osmose est efficace pour augmenter la résistance d’une argile silteuse molle. Après le traitement, un sol cimenté très dur s’est formé près des anodes. Cet article présente l’efficacité de ce processus sur le terrain. Neuf électrodes ont été installées en deux arrangements en forme de grille de 2 m × 2,5 m et 2 m × 5 m. La procédure d’essais était semblable à celle utilisée en laboratoire. Les résultats de ces essais ont montré qu’un sol cimenté très dur est formé, avec un diamètre de 50 à 60 cm autour des anodes, suite à un effet de cimentation entre les deux solutions chimiques et les particules de sol soumises à un champ électrique. La résistance au cisaillement en condition non drainée du sol entre les électrodes a augmenté considérablement, à l’exception des zones de sol cimenté très dur. L’inversion de la polarité après l’application de la polarité normale n’a pas produit d’amélioration en termes de résistance au cisaillement non drainé du sol, et de temps de traitement. DEWEY : 550 ISSN : 0008-3674 En ligne : http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=f [...]