Documents disponibles écrits par cet auteur

Design guidelines and full-scale verification for MSE walls with traffic barriers / K.-M. Kim in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 6 (Juin 2012) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 6 (Juin 2012) . - pp. 690–699 Titre : Design guidelines and full-scale verification for MSE walls with traffic barriers Type de document : texte imprimé Auteurs : K.-M. Kim, Auteur ; J.-L. Briaud, Auteur ; R. Bligh, Auteur Année de publication : 2012 Article en page(s) : pp. 690–699 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : AASHTO  load  and  resistance  factor  design  (LFRD)  Mechanically  stabilized  earth  (MSE)  wall  Traffic  barriers  Design  guideline Résumé : Millions of square meters of mechanically stabilized earth (MSE) retaining walls are constructed annually in the United States. For highway applications, a roadside barrier system is placed at the edge of the wall. This barrier system generally consists of an L-shape concrete structure so that if a vehicle hits the vertical part of the L shape (barrier), the horizontal part of the L (moment slab) provides the resisting moment during the impact. This impact must be resisted by the soil, the reinforcement, and the panels in the MSE wall. This paper gives guidelines on how to design the reinforcement for pullout and yielding and the panels for flexural and shear failure. It also gives the guidelines on how to ensure the stability of the barrier. These design guidelines are developed in terms of AASHTO load and resistance factor design procedures. In a second part, a full-scale crash test on an instrumented 2.79 m high MSE wall is described and analyzed. The wall and barrier behaved very satisfactorily and represented a verification of the proposed guidelines. Pressure distributions are presented for designing the top two layers of wall reinforcement to resist barrier impact forces. A 44.5-kN static equivalent load is recommended for evaluating the stability of the barrier and moment slab system. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000642 [article] Design guidelines and full-scale verification for MSE walls with traffic barriers [texte imprimé] / K.-M. Kim, Auteur ; J.-L. Briaud, Auteur ; R. Bligh, Auteur . - 2012 . - pp. 690–699. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 138 N° 6 (Juin 2012) . - pp. 690–699 Mots-clés : AASHTO  load  and  resistance  factor  design  (LFRD)  Mechanically  stabilized  earth  (MSE)  wall  Traffic  barriers  Design  guideline Résumé : Millions of square meters of mechanically stabilized earth (MSE) retaining walls are constructed annually in the United States. For highway applications, a roadside barrier system is placed at the edge of the wall. This barrier system generally consists of an L-shape concrete structure so that if a vehicle hits the vertical part of the L shape (barrier), the horizontal part of the L (moment slab) provides the resisting moment during the impact. This impact must be resisted by the soil, the reinforcement, and the panels in the MSE wall. This paper gives guidelines on how to design the reinforcement for pullout and yielding and the panels for flexural and shear failure. It also gives the guidelines on how to ensure the stability of the barrier. These design guidelines are developed in terms of AASHTO load and resistance factor design procedures. In a second part, a full-scale crash test on an instrumented 2.79 m high MSE wall is described and analyzed. The wall and barrier behaved very satisfactorily and represented a verification of the proposed guidelines. Pressure distributions are presented for designing the top two layers of wall reinforcement to resist barrier impact forces. A 44.5-kN static equivalent load is recommended for evaluating the stability of the barrier and moment slab system. ISSN : 1090-0241 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000642

Full-scale impact test of four traffic barriers on top of an instrumented MSE wall / K.-M. Kim in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 3 (Mars 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 3 (Mars 2010) . - pp. 431-438 Titre : Full-scale impact test of four traffic barriers on top of an instrumented MSE wall Type de document : texte imprimé Auteurs : K.-M. Kim, Auteur ; J.-L. Briaud, Auteur ; A. Abu-Odeh, Auteur Article en page(s) : pp. 431-438 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Impact  text  Traffic  barrier  Pullout  Reinforcement  Mechanically  stabilized  earthwalls Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents the results of four full-scale impact tests against barriers placed on top of an instrumented mechanically stabilized earth (MSE) wall. The impact was created by a head-on collision of a 2,268-kg bogie going at about 32.2 km/h. The barriers were New Jersey and vertical wall barriers with a 1.37-m-wide moment slab in 9.14-m-long sections. The wall was 1.52 m high with one panel and two layers of reinforcement. The reinforcement was 2.44-m-long strips, 4.88-m-long strips, and 2.44-m-long bar mats. The backfill was crushed rock. The instrumentation consisted of accelerometers, strain gauges, contact switch, displacement targets, string lines, and high-speed cameras. The test was designed to represent a commonly used installation in current practice including an impact load on the barrier at least equal to 240 kN. Most of the barriers sustained significant damage but overall the behavior of the wall was satisfactory since the displacements of the panels were minimal (less than 25 mm) and the panel damage was acceptable except possibly in the case of the 4.88-m-long strips. The loads measured in the reinforcement indicate that the reinforcement was brought to its ultimate capacity for the duration of the impact but since the impact duration was so short and since the displacements of the panels were within tolerable limits of 25 mm, this is considered acceptable. The use of the longer strips (4.88-m-long strips) leads to slightly smaller panel displacements and higher panel stresses as evidenced by a bending crack in the panel. The 2.44-m-long strips permitted more displacement of the wall panels, but the magnitude of the displacement was considered to be tolerable. The measured maximum dynamic loads in the strips were found to be 3–5 times higher than the calculated maximum static loads by AASHTO guidelines. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...] [article] Full-scale impact test of four traffic barriers on top of an instrumented MSE wall [texte imprimé] / K.-M. Kim, Auteur ; J.-L. Briaud, Auteur ; A. Abu-Odeh, Auteur . - pp. 431-438. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 3 (Mars 2010) . - pp. 431-438 Mots-clés : Impact  text  Traffic  barrier  Pullout  Reinforcement  Mechanically  stabilized  earthwalls Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : This paper presents the results of four full-scale impact tests against barriers placed on top of an instrumented mechanically stabilized earth (MSE) wall. The impact was created by a head-on collision of a 2,268-kg bogie going at about 32.2 km/h. The barriers were New Jersey and vertical wall barriers with a 1.37-m-wide moment slab in 9.14-m-long sections. The wall was 1.52 m high with one panel and two layers of reinforcement. The reinforcement was 2.44-m-long strips, 4.88-m-long strips, and 2.44-m-long bar mats. The backfill was crushed rock. The instrumentation consisted of accelerometers, strain gauges, contact switch, displacement targets, string lines, and high-speed cameras. The test was designed to represent a commonly used installation in current practice including an impact load on the barrier at least equal to 240 kN. Most of the barriers sustained significant damage but overall the behavior of the wall was satisfactory since the displacements of the panels were minimal (less than 25 mm) and the panel damage was acceptable except possibly in the case of the 4.88-m-long strips. The loads measured in the reinforcement indicate that the reinforcement was brought to its ultimate capacity for the duration of the impact but since the impact duration was so short and since the displacements of the panels were within tolerable limits of 25 mm, this is considered acceptable. The use of the longer strips (4.88-m-long strips) leads to slightly smaller panel displacements and higher panel stresses as evidenced by a bending crack in the panel. The 2.44-m-long strips permitted more displacement of the wall panels, but the magnitude of the displacement was considered to be tolerable. The measured maximum dynamic loads in the strips were found to be 3–5 times higher than the calculated maximum static loads by AASHTO guidelines. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...]

Levee erosion by overtopping in New Orleans during the Katrina Hurricane / J.-L. Briaud in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°5 (Mai 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°5 (Mai 2008) . - pp. 618–632 Titre : Levee erosion by overtopping in New Orleans during the Katrina Hurricane Type de document : texte imprimé Auteurs : J.-L. Briaud, Auteur ; Chen, C. H., Auteur ; A. V. Govindasamy, Auteur Année de publication : 2008 Article en page(s) : pp. 618–632 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Levees  Erosion  Louisiana  Hurricanes Résumé : Erodibility of a soil is defined here as the relationship between the erosion rate of a soil dz∕dt and the velocity v of the water flowing over it, or the relationship between the erosion rate of a soil dz∕dt and the shear stress developed by the water at the water-soil interface. This is called the erosion function. The test used to measure the erosion function of the levee soils is the erosion function apparatus test. The test consists of eroding a soil sample by pushing it out of a thin wall steel tube and recording the erosion rate for a given velocity of the water flowing over it. Several velocities are used and the erosion function is defined. A new erosion category chart is proposed to reduce the erodibility of a soil or rock to a single category number. Twenty three samples were retrieved from 11 locations at the surface of the levees around New Orleans. Thirteen were samples from Shelby tubes while ten were bag samples. The results obtained show a large variation of erosion resistance among the soils tested. Some of the levees associated with the location of the samples resisted the overtopping erosion very well; others eroded completely. On the basis of the erosion test results and of the observed behavior of the levees during the hurricane, a chart is presented which can be used to select soils for overtopping resistance. Numerical simulations were performed using the program CHEN 3D to obtain the distribution of velocity vectors in the overtopping flow and of shear stresses at the interface between the water and the levee surface. The comparison of the numerical simulation results and of the erosion function gives added credibility to the proposed levee overtopping erosion chart. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A5%2861 [...] [article] Levee erosion by overtopping in New Orleans during the Katrina Hurricane [texte imprimé] / J.-L. Briaud, Auteur ; Chen, C. H., Auteur ; A. V. Govindasamy, Auteur . - 2008 . - pp. 618–632. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°5 (Mai 2008) . - pp. 618–632 Mots-clés : Levees  Erosion  Louisiana  Hurricanes Résumé : Erodibility of a soil is defined here as the relationship between the erosion rate of a soil dz∕dt and the velocity v of the water flowing over it, or the relationship between the erosion rate of a soil dz∕dt and the shear stress developed by the water at the water-soil interface. This is called the erosion function. The test used to measure the erosion function of the levee soils is the erosion function apparatus test. The test consists of eroding a soil sample by pushing it out of a thin wall steel tube and recording the erosion rate for a given velocity of the water flowing over it. Several velocities are used and the erosion function is defined. A new erosion category chart is proposed to reduce the erodibility of a soil or rock to a single category number. Twenty three samples were retrieved from 11 locations at the surface of the levees around New Orleans. Thirteen were samples from Shelby tubes while ten were bag samples. The results obtained show a large variation of erosion resistance among the soils tested. Some of the levees associated with the location of the samples resisted the overtopping erosion very well; others eroded completely. On the basis of the erosion test results and of the observed behavior of the levees during the hurricane, a chart is presented which can be used to select soils for overtopping resistance. Numerical simulations were performed using the program CHEN 3D to obtain the distribution of velocity vectors in the overtopping flow and of shear stresses at the interface between the water and the levee surface. The comparison of the numerical simulation results and of the erosion function gives added credibility to the proposed levee overtopping erosion chart. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A5%2861 [...]