Documents disponibles écrits par cet auteur

Experimental analysis of the cyclic behaviour of kaolin at high temperature / C. Cekerevac in Géotechnique, Vol. 60 N° 8 (Août 2010) 

Public ISBD [article]  in Géotechnique > Vol. 60 N° 8 (Août 2010) . - pp. 651–655 Titre : Experimental analysis of the cyclic behaviour of kaolin at high temperature Type de document : texte imprimé Auteurs : C. Cekerevac, Auteur ; L. Laloui, Auteur Année de publication : 2011 Article en page(s) : pp. 651–655 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Shear  strength  Liquefaction  Clays  Laboratory  tests  Temperature  effects  Earthquakes Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the results of an experimental study related to thermal effects on kaolin clay cyclic mobility. The thermal effects were identified by comparing the experimental results of cyclic triaxial tests performed at high temperature (90°C) with results of the same type of test carried out at ambient temperature (22°C). For the testing, a new temperature-controlled triaxial apparatus, developed by the authors, was employed. Experimental evidence shows that shear cycles on the heated samples induced smaller axial strain and pore-water pressure per cycle in comparison with the unheated samples. In addition, shear-induced pore-water pressure at large strains in the heated sample was slightly lower than in the unheated sample. In other words, the heated samples behaved as if they were denser, which is a result of thermal hardening. These results may be applied in geotechnical and earthquake engineering applications as a soil improvement technique. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.7.00017 [article] Experimental analysis of the cyclic behaviour of kaolin at high temperature [texte imprimé] / C. Cekerevac, Auteur ; L. Laloui, Auteur . - 2011 . - pp. 651–655. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 60 N° 8 (Août 2010) . - pp. 651–655 Mots-clés : Shear  strength  Liquefaction  Clays  Laboratory  tests  Temperature  effects  Earthquakes Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the results of an experimental study related to thermal effects on kaolin clay cyclic mobility. The thermal effects were identified by comparing the experimental results of cyclic triaxial tests performed at high temperature (90°C) with results of the same type of test carried out at ambient temperature (22°C). For the testing, a new temperature-controlled triaxial apparatus, developed by the authors, was employed. Experimental evidence shows that shear cycles on the heated samples induced smaller axial strain and pore-water pressure per cycle in comparison with the unheated samples. In addition, shear-induced pore-water pressure at large strains in the heated sample was slightly lower than in the unheated sample. In other words, the heated samples behaved as if they were denser, which is a result of thermal hardening. These results may be applied in geotechnical and earthquake engineering applications as a soil improvement technique. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.7.00017

Temperature-dependent internal friction of clay in a cylindrical heat source problem / T. Hueckel in Géotechnique, Vol. 61 N° 10 (Octobre 2010) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 10 (Octobre 2010) . - pp. 831-844 Titre : Temperature-dependent internal friction of clay in a cylindrical heat source problem Type de document : texte imprimé Auteurs : T. Hueckel, Auteur ; B. Francois, Auteur ; L. Laloui, Auteur Année de publication : 2011 Article en page(s) : pp. 831-844 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Friction  Temperature  effects  Numerical  modelling  Failure  Clays Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : The effect of the temperature dependence of the internal friction angle is studied in a boundary value problem simulating the impact of a cylindrical heat source on the soil mass in which it is embedded. This follows a previous study which shows that such temperature dependence may substantially affect the interpretation of thermal failure in laboratory experiments. Even if the thermal increase of the internal friction is quite modest (less than 20% in terms of the critical state parameter, M), it affects quite significantly the effective stress path near the heat source. The effective stress path approaches the yield locus and the critical state at significantly higher principal stress difference values for the variable internal friction than for the M = const case. The ‘mean effective stress distance from the critical state' is substantially reduced during heating, which in the case of small perturbations of any parameter may lead to potentially unstable or statically inadmissible behaviour. The solutions obtained allow one to identify zones of influence around the heat source of several variables of interest. The two fields most affected by the thermal sensitivity of M are that of the axial stress, dropping significantly near the heat source, and that of the appearance of the thermoplastic strain. Both zones of influence are reduced in size by almost half when the friction angle is increased by 20% over 70°. The presented results may be of relevance to the design of prototype in situ installations and their monitoring, and eventually of actual facilities for nuclear waste disposal. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.p.124 [article] Temperature-dependent internal friction of clay in a cylindrical heat source problem [texte imprimé] / T. Hueckel, Auteur ; B. Francois, Auteur ; L. Laloui, Auteur . - 2011 . - pp. 831-844. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 10 (Octobre 2010) . - pp. 831-844 Mots-clés : Friction  Temperature  effects  Numerical  modelling  Failure  Clays Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : The effect of the temperature dependence of the internal friction angle is studied in a boundary value problem simulating the impact of a cylindrical heat source on the soil mass in which it is embedded. This follows a previous study which shows that such temperature dependence may substantially affect the interpretation of thermal failure in laboratory experiments. Even if the thermal increase of the internal friction is quite modest (less than 20% in terms of the critical state parameter, M), it affects quite significantly the effective stress path near the heat source. The effective stress path approaches the yield locus and the critical state at significantly higher principal stress difference values for the variable internal friction than for the M = const case. The ‘mean effective stress distance from the critical state' is substantially reduced during heating, which in the case of small perturbations of any parameter may lead to potentially unstable or statically inadmissible behaviour. The solutions obtained allow one to identify zones of influence around the heat source of several variables of interest. The two fields most affected by the thermal sensitivity of M are that of the axial stress, dropping significantly near the heat source, and that of the appearance of the thermoplastic strain. Both zones of influence are reduced in size by almost half when the friction angle is increased by 20% over 70°. The presented results may be of relevance to the design of prototype in situ installations and their monitoring, and eventually of actual facilities for nuclear waste disposal. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.9.p.124