Documents disponibles écrits par cet auteur

Case histories in soil and rock erosion / Jean-Louis Briaud in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°10 (Octobre 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°10 (Octobre 2008) . - pp. 1425–1447 Titre : Case histories in soil and rock erosion : Woodrow Wilson Bridge, Brazos River Meander, Normandy Cliffs, and New Orleans Levees Type de document : texte imprimé Auteurs : Jean-Louis Briaud, Auteur Année de publication : 2008 Article en page(s) : pp. 1425–1447 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : History  Erosion  Bridges  Levees  Cliffs  Rivers  Washington  D.C.  France  Louisiana  Texas Résumé : This lecture presents four case history examples of erosion processes. Because the topic of soil and rock erosion is relatively underdeveloped in geotechnical engineering, an introduction precedes the case histories to describe some fundamental aspects of erosion. Erosion involves the soil or rock through its erodibility, the water through its velocity, and the geometry of the obstacle through its size and shape. Knowledge of these three components is needed for any erosion problem to be studied and solved. A set of fundamental issues are addressed in the first part including an erodibility classification for soils and rocks, an explanation of the stresses imposed by the water on the soil-water or rock-water interface, and an explanation of how the geometry impacts the problem. The Woodrow Wilson Bridge case history outlines a new and less conservative method to compute the scour depth and gives examples of bridge scour calculations. The Brazos River meander case history outlines a new method to predict meander migration and gives an example of migration calculations. The Pointe du Hoc case history gives an explanation of a process of rock cliff erosion. The New Orleans levees case history gives an example of erosion of levees by overtopping and proposes an erosion design chart for levee overtopping. Whenever possible the results are presented in a probabilistic fashion. All case histories make use of the erosion function apparatus, an apparatus developed to quantify the erodibility of a soil or rock and to give the constitutive law for erosion problems: the erosion function. The power point slides for the lecture including many photos of the case histories are available at ⟨http://ceprofs.tamu.edu/briaud/⟩ under “Lectures” and the video (DVD) of the lecture is available from the author, free of charge. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A10%281 [...] [article] Case histories in soil and rock erosion : Woodrow Wilson Bridge, Brazos River Meander, Normandy Cliffs, and New Orleans Levees [texte imprimé] / Jean-Louis Briaud, Auteur . - 2008 . - pp. 1425–1447. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°10 (Octobre 2008) . - pp. 1425–1447 Mots-clés : History  Erosion  Bridges  Levees  Cliffs  Rivers  Washington  D.C.  France  Louisiana  Texas Résumé : This lecture presents four case history examples of erosion processes. Because the topic of soil and rock erosion is relatively underdeveloped in geotechnical engineering, an introduction precedes the case histories to describe some fundamental aspects of erosion. Erosion involves the soil or rock through its erodibility, the water through its velocity, and the geometry of the obstacle through its size and shape. Knowledge of these three components is needed for any erosion problem to be studied and solved. A set of fundamental issues are addressed in the first part including an erodibility classification for soils and rocks, an explanation of the stresses imposed by the water on the soil-water or rock-water interface, and an explanation of how the geometry impacts the problem. The Woodrow Wilson Bridge case history outlines a new and less conservative method to compute the scour depth and gives examples of bridge scour calculations. The Brazos River meander case history outlines a new method to predict meander migration and gives an example of migration calculations. The Pointe du Hoc case history gives an explanation of a process of rock cliff erosion. The New Orleans levees case history gives an example of erosion of levees by overtopping and proposes an erosion design chart for levee overtopping. Whenever possible the results are presented in a probabilistic fashion. All case histories make use of the erosion function apparatus, an apparatus developed to quantify the erodibility of a soil or rock and to give the constitutive law for erosion problems: the erosion function. The power point slides for the lecture including many photos of the case histories are available at ⟨http://ceprofs.tamu.edu/briaud/⟩ under “Lectures” and the video (DVD) of the lecture is available from the author, free of charge. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A10%281 [...]

Improved approach to construct constitutive surfaces for stable-structured soils covering both saturated and unsaturated conditions / Xiong Zhang in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N° 6 (Juin 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N° 6 (Juin 2008) . - pp. 876–882 Titre : Improved approach to construct constitutive surfaces for stable-structured soils covering both saturated and unsaturated conditions Type de document : texte imprimé Auteurs : Xiong Zhang, Auteur ; Jean-Louis Briaud, Auteur Année de publication : 2010 Article en page(s) : pp. 876–882 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Void  ratio  Saturated  soils  Unsaturated  soils  Laboratory  tests  Surface  properties Résumé : Constitutive surfaces are indispensable for investigation of the behavior of soils. Saturated and unsaturated soils coexist in most engineering problems and it is meaningful to develop constitutive surfaces covering both saturated and unsaturated conditions which help to investigate the behavior for both saturated and unsaturated soils in a unified way. At present, the methodologies used for saturated and unsaturated soils are different and few researchers consider the constitutive surfaces for saturated soils. For unsaturated soils, the suction-controlled triaxial tests are usually laborious, time consuming, costly, and may not justify routine engineering projects. This paper discusses the role of constitutive surfaces in soil mechanics and presents an improved approach over existing interpolation methods to construct the constitutive surfaces for saturated and unsaturated conditions for a stable-structured soil using simple laboratory tests. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A6%2887 [...] [article] Improved approach to construct constitutive surfaces for stable-structured soils covering both saturated and unsaturated conditions [texte imprimé] / Xiong Zhang, Auteur ; Jean-Louis Briaud, Auteur . - 2010 . - pp. 876–882. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N° 6 (Juin 2008) . - pp. 876–882 Mots-clés : Void  ratio  Saturated  soils  Unsaturated  soils  Laboratory  tests  Surface  properties Résumé : Constitutive surfaces are indispensable for investigation of the behavior of soils. Saturated and unsaturated soils coexist in most engineering problems and it is meaningful to develop constitutive surfaces covering both saturated and unsaturated conditions which help to investigate the behavior for both saturated and unsaturated soils in a unified way. At present, the methodologies used for saturated and unsaturated soils are different and few researchers consider the constitutive surfaces for saturated soils. For unsaturated soils, the suction-controlled triaxial tests are usually laborious, time consuming, costly, and may not justify routine engineering projects. This paper discusses the role of constitutive surfaces in soil mechanics and presents an improved approach over existing interpolation methods to construct the constitutive surfaces for saturated and unsaturated conditions for a stable-structured soil using simple laboratory tests. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A6%2887 [...]

Probability of exceedance estimates for scour depth around bridge piers / Laura C. Bolduc in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°2 (Fevrier 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°2 (Fevrier 2008) . - pp. 175–184 Titre : Probability of exceedance estimates for scour depth around bridge piers Type de document : texte imprimé Auteurs : Laura C. Bolduc, Auteur ; Gardoni, Paolo, Auteur ; Jean-Louis Briaud, Auteur Année de publication : 2008 Article en page(s) : pp. 175–184 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Bridges  Piers  Scour  Probability  Estimation Résumé : Scour at a bridge pier is the formation of a hole around the pier due to the erosion of soil by flowing water; this hole in the soil reduces the carrying capacity of the foundation and the pier. Excessive scour can cause a bridge pier to fail without warning. Current predictions of the depth of the scour hole around a bridge pier are based on deterministic models. This paper considers two alternative deterministic models to predict scour depth. For each deterministic model, a corresponding probabilistic model is constructed using a Bayesian statistical approach and available field and experimental data. The developed probabilistic models account for the estimated bias in the deterministic models and for the model uncertainty. Parameters from both prediction models are compared to determine their accuracy. The developed probabilistic models are used to estimate the probability of exceedance of scour depth around bridge piers. The method is demonstrated on an example bridge pier. The paper addresses model uncertainties for given hydrologic variables. Hydrologic uncertainties have been presented in a separate paper. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A2%2817 [...] [article] Probability of exceedance estimates for scour depth around bridge piers [texte imprimé] / Laura C. Bolduc, Auteur ; Gardoni, Paolo, Auteur ; Jean-Louis Briaud, Auteur . - 2008 . - pp. 175–184. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°2 (Fevrier 2008) . - pp. 175–184 Mots-clés : Bridges  Piers  Scour  Probability  Estimation Résumé : Scour at a bridge pier is the formation of a hole around the pier due to the erosion of soil by flowing water; this hole in the soil reduces the carrying capacity of the foundation and the pier. Excessive scour can cause a bridge pier to fail without warning. Current predictions of the depth of the scour hole around a bridge pier are based on deterministic models. This paper considers two alternative deterministic models to predict scour depth. For each deterministic model, a corresponding probabilistic model is constructed using a Bayesian statistical approach and available field and experimental data. The developed probabilistic models account for the estimated bias in the deterministic models and for the model uncertainty. Parameters from both prediction models are compared to determine their accuracy. The developed probabilistic models are used to estimate the probability of exceedance of scour depth around bridge piers. The method is demonstrated on an example bridge pier. The paper addresses model uncertainties for given hydrologic variables. Hydrologic uncertainties have been presented in a separate paper. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A2%2817 [...]