Documents disponibles écrits par cet auteur

Analysis of cases of gravity quaywall movement during earthquakes / G.-S. Hwang in Géotechnique, Vol. 61 N° 3 (Mars 2011) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 3 (Mars 2011) . - pp. 199–210 Titre : Analysis of cases of gravity quaywall movement during earthquakes Type de document : texte imprimé Auteurs : G.-S. Hwang, Auteur ; Chen, C. H., Auteur Année de publication : 2011 Article en page(s) : pp. 199–210 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Liquefaction  Retaining  walls  Pore  pressures  Earthquakes  Earth  pressure  Case  history Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Earthquakes have damaged harbour structures, both recently and historically. Vivid examples are provided by two recent events: the Kobe earthquake (Ml = 7·2, 1995), involving Kobe port, Port Island, Rokko Island and Fukae Island in Japan; and the Chi-Chi earthquake (Ml = 7·3, 1999), involving Taichung Harbour in Taiwan. The results of surveys of deformation patterns of the ground surface at the two harbours after the events, and the published results of well-planned shaking-table tests, are analysed: the shaking-table tests provided images of the deformed profiles for the submerged backfill of a scaled-down quaywall model. On the basis of these data a simple model is proposed to explain the failure mechanism in large lateral displacements of gravity quaywalls during earthquakes. The results show that the Mononobe–Okabe theory underestimates the resultant of earth pressure from the liquefied submerged backfill. For the cases of the two earthquakes studied in this paper, several dimensionless parameters obtained by using the proposed simple model have similar values. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.3625 [article] Analysis of cases of gravity quaywall movement during earthquakes [texte imprimé] / G.-S. Hwang, Auteur ; Chen, C. H., Auteur . - 2011 . - pp. 199–210. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 3 (Mars 2011) . - pp. 199–210 Mots-clés : Liquefaction  Retaining  walls  Pore  pressures  Earthquakes  Earth  pressure  Case  history Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Earthquakes have damaged harbour structures, both recently and historically. Vivid examples are provided by two recent events: the Kobe earthquake (Ml = 7·2, 1995), involving Kobe port, Port Island, Rokko Island and Fukae Island in Japan; and the Chi-Chi earthquake (Ml = 7·3, 1999), involving Taichung Harbour in Taiwan. The results of surveys of deformation patterns of the ground surface at the two harbours after the events, and the published results of well-planned shaking-table tests, are analysed: the shaking-table tests provided images of the deformed profiles for the submerged backfill of a scaled-down quaywall model. On the basis of these data a simple model is proposed to explain the failure mechanism in large lateral displacements of gravity quaywalls during earthquakes. The results show that the Mononobe–Okabe theory underestimates the resultant of earth pressure from the liquefied submerged backfill. For the cases of the two earthquakes studied in this paper, several dimensionless parameters obtained by using the proposed simple model have similar values. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.3625

Coupling behavior of wire ropes subjected to tensile impulses / Yen, J. Y. R. in Journal of engineering mechanics, Vol. 135 N° 8 (Août 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N° 8 (Août 2009) . - pp. 796-801 Titre : Coupling behavior of wire ropes subjected to tensile impulses Type de document : texte imprimé Auteurs : Yen, J. Y. R., Auteur ; Chen, C. H., Auteur ; Chung, S. C., Auteur Article en page(s) : pp. 796-801 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Coupling  Wire  products  Tensile  stress  Static  loads. Résumé : To determine the stress state of a wire rope is tedious although analytical solution of a simple rope subjected to static load is available. While facing the problems involving complex ropes, it is usual practice to take approximations based upon the concepts of an average stress state for the constitutive ropes or for every wire. For a statically loaded cable superimposed with a tensile impulse, practically in sudden lifting of a heavy weight, the coupled axial-shearing strain waves in the cable has rarely been studied and explored through analytical approaches. Based on Costello's force-deformation relationship and elastic wave propagation theory, analysis procedures and results are presented in this paper. Time-dependent coupled axial-torsional displacements and axial-shearing strain waves in a simple straight wire rope, due to a longitudinal impact at one end, are obtained. At the instance of the strike, a pair of coupled primary axial-torsional waves is created and begins to travel in the cable independently with different speed. Meanwhile, a coupling induced secondary torsional wave and an axial wave were observed to travel with the primary axial wave and the primary torsional wave, respectively. Phenomenon such as the traveling, reflections from ends, and intersections of the primary waves as well as the secondary wave are presented. Information provided in this paper would be useful in the study of unexpected overstress and/or fatigue DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JENMDT&smode=strres [...] [article] Coupling behavior of wire ropes subjected to tensile impulses [texte imprimé] / Yen, J. Y. R., Auteur ; Chen, C. H., Auteur ; Chung, S. C., Auteur . - pp. 796-801. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N° 8 (Août 2009) . - pp. 796-801 Mots-clés : Coupling  Wire  products  Tensile  stress  Static  loads. Résumé : To determine the stress state of a wire rope is tedious although analytical solution of a simple rope subjected to static load is available. While facing the problems involving complex ropes, it is usual practice to take approximations based upon the concepts of an average stress state for the constitutive ropes or for every wire. For a statically loaded cable superimposed with a tensile impulse, practically in sudden lifting of a heavy weight, the coupled axial-shearing strain waves in the cable has rarely been studied and explored through analytical approaches. Based on Costello's force-deformation relationship and elastic wave propagation theory, analysis procedures and results are presented in this paper. Time-dependent coupled axial-torsional displacements and axial-shearing strain waves in a simple straight wire rope, due to a longitudinal impact at one end, are obtained. At the instance of the strike, a pair of coupled primary axial-torsional waves is created and begins to travel in the cable independently with different speed. Meanwhile, a coupling induced secondary torsional wave and an axial wave were observed to travel with the primary axial wave and the primary torsional wave, respectively. Phenomenon such as the traveling, reflections from ends, and intersections of the primary waves as well as the secondary wave are presented. Information provided in this paper would be useful in the study of unexpected overstress and/or fatigue DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JENMDT&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 [...]