Documents disponibles écrits par cet auteur

Bayesian updating of soil parameters for braced excavations using field observations / C. Hsein Juang 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. 395-406 Titre : Bayesian updating of soil parameters for braced excavations using field observations Type de document : texte imprimé Auteurs : C. Hsein Juang, Auteur ; Zhe Luo, Auteur ; Sez Atamturktur, Auteur Année de publication : 2013 Article en page(s) : pp. 395-406 Note générale : geotechnique Langues : Anglais (eng) Mots-clés : Bayesian  analysis;  Markov  process;  Monte  Carlo  method;  simulation;  algorithms;  excavation;  walls;  deflection;  bracing Résumé : A Bayesian framework using field observations for back-analysis and updating of soil parameters in a multistage braced excavation is presented. Because of the uncertainties originating from the poorly known soil parameters, the imperfect analysis model, and other factors such as construction variability, the soil parameters can only be inferred as probability distributions. In this paper, these posterior distributions are derived using the Markov chain Monte Carlo (MCMC) sampling method implemented with the Metropolis-Hastings algorithm. In the proposed framework, Bayesian updating is first realized with one type of response observation (maximum wall deflection or maximum settlement), and then this Bayesian framework is extended to allow for simultaneous use of two types of response observations in the updating. The proposed framework is illustrated with a quality excavation case and shown effective regardless of the prior knowledge of soil parameters and type of response observations adopted. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000782 [article] Bayesian updating of soil parameters for braced excavations using field observations [texte imprimé] / C. Hsein Juang, Auteur ; Zhe Luo, Auteur ; Sez Atamturktur, Auteur . - 2013 . - pp. 395-406. geotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 3 (Mars 2013) . - pp. 395-406 Mots-clés : Bayesian  analysis;  Markov  process;  Monte  Carlo  method;  simulation;  algorithms;  excavation;  walls;  deflection;  bracing Résumé : A Bayesian framework using field observations for back-analysis and updating of soil parameters in a multistage braced excavation is presented. Because of the uncertainties originating from the poorly known soil parameters, the imperfect analysis model, and other factors such as construction variability, the soil parameters can only be inferred as probability distributions. In this paper, these posterior distributions are derived using the Markov chain Monte Carlo (MCMC) sampling method implemented with the Metropolis-Hastings algorithm. In the proposed framework, Bayesian updating is first realized with one type of response observation (maximum wall deflection or maximum settlement), and then this Bayesian framework is extended to allow for simultaneous use of two types of response observations in the updating. The proposed framework is illustrated with a quality excavation case and shown effective regardless of the prior knowledge of soil parameters and type of response observations adopted. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000782

Bootstrapping for characterizing the effect of uncertainty in sample statistics for braced excavations / Zhe Luo in Journal of geotechnical and geoenvironmental engineering, Vol. 139 N° 1 (Janvier 2013) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 1 (Janvier 2013) . - pp. 13–23 Titre : Bootstrapping for characterizing the effect of uncertainty in sample statistics for braced excavations Type de document : texte imprimé Auteurs : Zhe Luo, Auteur ; Sez Atamturktur, Auteur ; C. Hsein Juang, Auteur Année de publication : 2013 Article en page(s) : pp. 13–23 Note générale : geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : excavation;  bracing;  serviceability;  probability  distribution;  parameters;  uncertainty  principles;  statistics Résumé : A simple procedure for assessing the probability of serviceability failure in a braced excavation involving bootstrapping to characterize the effect of uncertainty in sample statistics is presented. Here, the failure is defined when an excavation system’s response in terms of the maximum wall deflection or ground settlement that exceeds the limiting value specified by the client or in an applicable code. The analysis for the probability of failure (or probability of exceedance) necessitates an evaluation of the means and SDs of critical soil parameters. In geotechnical practice, these means and SDs are often estimated from a very limited data set, which can lead to uncertainty in the derived sample statistics. Thus, in this study bootstrapping is used to characterize the uncertainty or variation of sample statistics and its effect on the failure probability. Through the bootstrapping analysis, the probability of exceedance can be presented as a confidence interval instead of a single, fixed probability. The information gained should enable the engineer to make a more rational assessment of the risk of serviceability failure in a braced excavation. The study points to the potential of the bootstrap method in coping with the problem of having to evaluate failure probability with uncertain sample statistics. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000734 [article] Bootstrapping for characterizing the effect of uncertainty in sample statistics for braced excavations [texte imprimé] / Zhe Luo, Auteur ; Sez Atamturktur, Auteur ; C. Hsein Juang, Auteur . - 2013 . - pp. 13–23. geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 139 N° 1 (Janvier 2013) . - pp. 13–23 Mots-clés : excavation;  bracing;  serviceability;  probability  distribution;  parameters;  uncertainty  principles;  statistics Résumé : A simple procedure for assessing the probability of serviceability failure in a braced excavation involving bootstrapping to characterize the effect of uncertainty in sample statistics is presented. Here, the failure is defined when an excavation system’s response in terms of the maximum wall deflection or ground settlement that exceeds the limiting value specified by the client or in an applicable code. The analysis for the probability of failure (or probability of exceedance) necessitates an evaluation of the means and SDs of critical soil parameters. In geotechnical practice, these means and SDs are often estimated from a very limited data set, which can lead to uncertainty in the derived sample statistics. Thus, in this study bootstrapping is used to characterize the uncertainty or variation of sample statistics and its effect on the failure probability. Through the bootstrapping analysis, the probability of exceedance can be presented as a confidence interval instead of a single, fixed probability. The information gained should enable the engineer to make a more rational assessment of the risk of serviceability failure in a braced excavation. The study points to the potential of the bootstrap method in coping with the problem of having to evaluate failure probability with uncertain sample statistics. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000734

Simplified approach for reliability-based design against basal-heave failure in braced excavations considering spatial effect / Zhe Luo 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. 441–450 Titre : Simplified approach for reliability-based design against basal-heave failure in braced excavations considering spatial effect Type de document : texte imprimé Auteurs : Zhe Luo, Auteur ; Sez Atamturktur, Auteur ; Yuanqiang Cai, Auteur Année de publication : 2012 Article en page(s) : pp. 441–450 Note générale : Géologie appliquée Langues : Anglais (eng) Mots-clés : Basal-heave  Excavation  Factor  of  safety  First-order  reliability  method  Probability  Random  field  Spatial  variability Résumé : This paper presents a simplified approach for reliability analysis of basal heave in a braced excavation considering the spatial variability of soil parameters, The first-order reliability method (FORM) with a variance reduction technique is employed to model the spatial variability in lieu of the conventional random field modeling (RFM). The proposed approach yields results that are comparable with those obtained using the conventional RFM approach that relies on Monte Carlo simulation. The proposed approach requires much less computational effort, is easy to use, and has potential as a practical tool for reliability-based design that has to deal with spatial variability of soils. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000621 [article] Simplified approach for reliability-based design against basal-heave failure in braced excavations considering spatial effect [texte imprimé] / Zhe Luo, Auteur ; Sez Atamturktur, Auteur ; Yuanqiang Cai, Auteur . - 2012 . - pp. 441–450. Géologie appliquée Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 4 (Avril 2012) . - pp. 441–450 Mots-clés : Basal-heave  Excavation  Factor  of  safety  First-order  reliability  method  Probability  Random  field  Spatial  variability Résumé : This paper presents a simplified approach for reliability analysis of basal heave in a braced excavation considering the spatial variability of soil parameters, The first-order reliability method (FORM) with a variance reduction technique is employed to model the spatial variability in lieu of the conventional random field modeling (RFM). The proposed approach yields results that are comparable with those obtained using the conventional RFM approach that relies on Monte Carlo simulation. The proposed approach requires much less computational effort, is easy to use, and has potential as a practical tool for reliability-based design that has to deal with spatial variability of soils. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000621