Documents disponibles écrits par cet auteur

A comparison of critical state models for sand under conditions of axial symmetry / A. R. Russell in Géotechnique, Vol. 60 N° 2 (Fevrier 2010) 

Public ISBD [article]  in Géotechnique > Vol. 60 N° 2 (Fevrier 2010) . - pp. 133–140 Titre : A comparison of critical state models for sand under conditions of axial symmetry Type de document : texte imprimé Auteurs : A. R. Russell, Auteur ; D. Muir Wood, Auteur Année de publication : 2011 Article en page(s) : pp. 133–140 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Sands  Constitutive  relations  Elasticity  Plasticity  Stiffness  Numerical  modelling  and  analysis Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Three constitutive models constructed within the spirit of critical state soil mechanics are summarised and compared under conditions of axial symmetry. The models have been calibrated using drained and undrained triaxial compression tests on Hostun sand. The quality of the individual simulations is strongly influenced by the shape chosen for the critical state line at high stresses. Stress response envelopes have been produced in order to contrast the incremental stiffnesses that the models predict for stress and strain paths other than those used for simulation. Plots of second-order work have also been presented for each model. Negative second-order work for certain strain paths indicates the potential for instability and bifurcation of response. Non-associated flow is a basic feature of these models and potentially unstable states were found to occur at mobilised friction angles lower than the peak of the stress–strain response. The hardening moduli of the models are similar, even though they were developed from different starting assumptions. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/search?value1='sands'&option1=fulltext [article] A comparison of critical state models for sand under conditions of axial symmetry [texte imprimé] / A. R. Russell, Auteur ; D. Muir Wood, Auteur . - 2011 . - pp. 133–140. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 60 N° 2 (Fevrier 2010) . - pp. 133–140 Mots-clés : Sands  Constitutive  relations  Elasticity  Plasticity  Stiffness  Numerical  modelling  and  analysis Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Three constitutive models constructed within the spirit of critical state soil mechanics are summarised and compared under conditions of axial symmetry. The models have been calibrated using drained and undrained triaxial compression tests on Hostun sand. The quality of the individual simulations is strongly influenced by the shape chosen for the critical state line at high stresses. Stress response envelopes have been produced in order to contrast the incremental stiffnesses that the models predict for stress and strain paths other than those used for simulation. Plots of second-order work have also been presented for each model. Negative second-order work for certain strain paths indicates the potential for instability and bifurcation of response. Non-associated flow is a basic feature of these models and potentially unstable states were found to occur at mobilised friction angles lower than the peak of the stress–strain response. The hardening moduli of the models are similar, even though they were developed from different starting assumptions. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/search?value1='sands'&option1=fulltext

Photoelastic and photographic study of a granular material / D. Lesniewska in Géotechnique, Vol. 61 N° 7 (Juillet 2011) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 7 (Juillet 2011) . - pp. 605–611 Titre : Photoelastic and photographic study of a granular material Type de document : texte imprimé Auteurs : D. Lesniewska, Auteur ; D. Muir Wood, Auteur Année de publication : 2011 Article en page(s) : pp. 605–611 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Strain  localisation  Stress  analysis  Model  tests  Retaining  walls  Deformation Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Glass ballotini can be used as a special granular material that reveals information about stress conditions when viewed using polarised light. Simultaneously, techniques for observing displacement fields can be used to produce information about internal strains. The combination of photoelastic and photographic observation has potential for extending knowledge of internal conditions in two-dimensional samples of granular material. The procedures described in this note indicate some interesting possibilities for experimental soil mechanics. The use of digital photography with polarised light permits incremental results to be obtained from the photoelastic images. The use of digital photography in non-polarised light with particle image velocimetry analysis gives the opportunity to obtain experimental displacement and strain fields with great accuracy and local detail. The use of standard image processing and graphics software permits precise comparison of features of the incremental strain and stress fields by superimposing corresponding images. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.t.017 [article] Photoelastic and photographic study of a granular material [texte imprimé] / D. Lesniewska, Auteur ; D. Muir Wood, Auteur . - 2011 . - pp. 605–611. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 7 (Juillet 2011) . - pp. 605–611 Mots-clés : Strain  localisation  Stress  analysis  Model  tests  Retaining  walls  Deformation Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Glass ballotini can be used as a special granular material that reveals information about stress conditions when viewed using polarised light. Simultaneously, techniques for observing displacement fields can be used to produce information about internal strains. The combination of photoelastic and photographic observation has potential for extending knowledge of internal conditions in two-dimensional samples of granular material. The procedures described in this note indicate some interesting possibilities for experimental soil mechanics. The use of digital photography with polarised light permits incremental results to be obtained from the photoelastic images. The use of digital photography in non-polarised light with particle image velocimetry analysis gives the opportunity to obtain experimental displacement and strain fields with great accuracy and local detail. The use of standard image processing and graphics software permits precise comparison of features of the incremental strain and stress fields by superimposing corresponding images. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.t.017

Strain path controlled shear tests on an analogue granular material / E. Ibraim in Géotechnique, Vol. 60 N° 7 (Juillet 2010) 

Public ISBD [article]  in Géotechnique > Vol. 60 N° 7 (Juillet 2010) . - pp. 545–559 Titre : Strain path controlled shear tests on an analogue granular material Type de document : texte imprimé Auteurs : E. Ibraim, Auteur ; J. Lanier, Auteur ; D. Muir Wood, Auteur Année de publication : 2011 Article en page(s) : pp. 545–559 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Laboratory  tests  Stress  path  Constitutive  relations Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : A series of strain controlled tests have been performed on a two-dimensional analogue granular material, composed of three different sizes of rods, in a special laboratory apparatus which permits full control of plane deformations, including rotation of principal axes. These tests have been designed and used to explore certain constitutive conjectures concerning the mechanical behaviour of granular materials. The results, within the accuracy of the apparatus, show that irrespective of the initial stress history of the material, proportional strain paths (if continued for long enough) lead to proportional stress states (asymptotic states). The asymptotic states appear to be independent of the fixed imposed rotation of principal strain axes and at these states coaxiality between the principal stress direction and the principal incremental strain direction seems to be reached. A stress dilatancy relationship between the imposed dilatancy and the corresponding asymptotic stress ratio has been identified. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.100 [article] Strain path controlled shear tests on an analogue granular material [texte imprimé] / E. Ibraim, Auteur ; J. Lanier, Auteur ; D. Muir Wood, Auteur . - 2011 . - pp. 545–559. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 60 N° 7 (Juillet 2010) . - pp. 545–559 Mots-clés : Laboratory  tests  Stress  path  Constitutive  relations Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : A series of strain controlled tests have been performed on a two-dimensional analogue granular material, composed of three different sizes of rods, in a special laboratory apparatus which permits full control of plane deformations, including rotation of principal axes. These tests have been designed and used to explore certain constitutive conjectures concerning the mechanical behaviour of granular materials. The results, within the accuracy of the apparatus, show that irrespective of the initial stress history of the material, proportional strain paths (if continued for long enough) lead to proportional stress states (asymptotic states). The asymptotic states appear to be independent of the fixed imposed rotation of principal strain axes and at these states coaxiality between the principal stress direction and the principal incremental strain direction seems to be reached. A stress dilatancy relationship between the imposed dilatancy and the corresponding asymptotic stress ratio has been identified. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.100