Documents disponibles écrits par cet auteur

Influence of spatial variability on slope reliability using 2-D random fields / D. V. Griffiths in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 10 (Octobre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 10 (Octobre 2009) . - pp. 1367–1378 Titre : Influence of spatial variability on slope reliability using 2-D random fields Type de document : texte imprimé Auteurs : D. V. Griffiths, Auteur ; Jinsong Huang, Auteur ; Gordon A. Fenton, Auteur Année de publication : 2009 Article en page(s) : pp. 1367–1378 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Slope  stabilityFinite  element  methodProbabilityFailures Résumé : The paper investigates the probability of failure of slopes using both traditional and more advanced probabilistic analysis tools. The advanced method, called the random finite-element method, uses elastoplasticity in a finite-element model combined with random field theory in a Monte-Carlo framework. The traditional method, called the first-order reliability method, computes a reliability index which is the shortest distance (in units of directional equivalent standard deviations) from the equivalent mean-value point to the limit state surface and estimates the probability of failure from the reliability index. Numerical results show that simplified probabilistic analyses in which spatial variability of soil properties is not properly accounted for, can lead to unconservative estimates of the probability of failure if the coefficient of variation of the shear strength parameters exceeds a critical value. The influences of slope inclination, factor of safety (based on mean strength values), and cross correlation between strength parameters on this critical value have been investigated by parametric studies in this paper. The results indicate when probabilistic approaches, which do not model spatial variation, may lead to unconservative estimates of slope failure probability and when more advanced probabilistic methods are warranted. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000099 [article] Influence of spatial variability on slope reliability using 2-D random fields [texte imprimé] / D. V. Griffiths, Auteur ; Jinsong Huang, Auteur ; Gordon A. Fenton, Auteur . - 2009 . - pp. 1367–1378. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 10 (Octobre 2009) . - pp. 1367–1378 Mots-clés : Slope  stabilityFinite  element  methodProbabilityFailures Résumé : The paper investigates the probability of failure of slopes using both traditional and more advanced probabilistic analysis tools. The advanced method, called the random finite-element method, uses elastoplasticity in a finite-element model combined with random field theory in a Monte-Carlo framework. The traditional method, called the first-order reliability method, computes a reliability index which is the shortest distance (in units of directional equivalent standard deviations) from the equivalent mean-value point to the limit state surface and estimates the probability of failure from the reliability index. Numerical results show that simplified probabilistic analyses in which spatial variability of soil properties is not properly accounted for, can lead to unconservative estimates of the probability of failure if the coefficient of variation of the shear strength parameters exceeds a critical value. The influences of slope inclination, factor of safety (based on mean strength values), and cross correlation between strength parameters on this critical value have been investigated by parametric studies in this paper. The results indicate when probabilistic approaches, which do not model spatial variation, may lead to unconservative estimates of slope failure probability and when more advanced probabilistic methods are warranted. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000099

Numerical modelling of the trap door problem / N. C. Koutsabeloulis in Géotechnique, Vol. 39 N°1 (Mars 1989) 

Public ISBD [article]  in Géotechnique > Vol. 39 N°1 (Mars 1989) . - pp. 77 –89 Titre : Numerical modelling of the trap door problem Type de document : texte imprimé Auteurs : N. C. Koutsabeloulis, Auteur ; D. V. Griffiths, Auteur Année de publication : 2007 Article en page(s) : pp. 77 –89 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Trap  door  problem  Tunnel  design  Finite  element  analysis  Anchor  design Résumé : The trap door problem is a useful model for providing a clearer understanding of the stress distribution around civil engineering structures such as anchor plates and tunnels. The passive mode can be used either to compute the uplift force of anchors or any buried structure which may be idealized as an anchor; the active mode can be used to compute the gravitational flow of a granular material between vertical walls or the soil reaction curve for tunnel design. Both modes of displacement are modelled numerically in this Paper using the finite element method. The results are presented in the form of influence charts, which may be used for both the passive and active modes to provide failure loads for a range of geometries and soil properties, using non-dimensionalized parameters. The use of these equations is compared with results obtained from other sources using both physical and numerical models. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.1989.39.1.77 [article] Numerical modelling of the trap door problem [texte imprimé] / N. C. Koutsabeloulis, Auteur ; D. V. Griffiths, Auteur . - 2007 . - pp. 77 –89. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 39 N°1 (Mars 1989) . - pp. 77 –89 Mots-clés : Trap  door  problem  Tunnel  design  Finite  element  analysis  Anchor  design Résumé : The trap door problem is a useful model for providing a clearer understanding of the stress distribution around civil engineering structures such as anchor plates and tunnels. The passive mode can be used either to compute the uplift force of anchors or any buried structure which may be idealized as an anchor; the active mode can be used to compute the gravitational flow of a granular material between vertical walls or the soil reaction curve for tunnel design. Both modes of displacement are modelled numerically in this Paper using the finite element method. The results are presented in the form of influence charts, which may be used for both the passive and active modes to provide failure loads for a range of geometries and soil properties, using non-dimensionalized parameters. The use of these equations is compared with results obtained from other sources using both physical and numerical models. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.1989.39.1.77

One-dimensional consolidation theories for layered soil and coupled and uncoupled solutions by the finite-element method / J. Huang in Géotechnique, Vol. 60 N° 9 (Septembre 2010) 

Public ISBD [article]  in Géotechnique > Vol. 60 N° 9 (Septembre 2010) . - pp. 709–713 Titre : One-dimensional consolidation theories for layered soil and coupled and uncoupled solutions by the finite-element method Type de document : texte imprimé Auteurs : J. Huang, Auteur ; D. V. Griffiths, Auteur Année de publication : 2011 Article en page(s) : pp. 709–713 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Permeability  Finite-element  method  Consolidation  Compressibility Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : One-dimensional consolidation theories for layered soil have been re-examined. Coupled (settlement and excess pore pressure), uncoupled (excess pore pressure only) and the classical Terzaghi equation are solved by the finite-element method. By accounting only for changes in the coefficient of consolidation (c v), the classical Terzaghi approach is unable to satisfy the flow continuity conditions at the interface between layers. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.08.p.038 [article] One-dimensional consolidation theories for layered soil and coupled and uncoupled solutions by the finite-element method [texte imprimé] / J. Huang, Auteur ; D. V. Griffiths, Auteur . - 2011 . - pp. 709–713. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 60 N° 9 (Septembre 2010) . - pp. 709–713 Mots-clés : Permeability  Finite-element  method  Consolidation  Compressibility Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : One-dimensional consolidation theories for layered soil have been re-examined. Coupled (settlement and excess pore pressure), uncoupled (excess pore pressure only) and the classical Terzaghi equation are solved by the finite-element method. By accounting only for changes in the coefficient of consolidation (c v), the classical Terzaghi approach is unable to satisfy the flow continuity conditions at the interface between layers. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.08.p.038

Probabilistic analysis of coupled soil consolidation / Jinsong Huang 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. 417-430 Titre : Probabilistic analysis of coupled soil consolidation Type de document : texte imprimé Auteurs : Jinsong Huang, Auteur ; D. V. Griffiths, Auteur ; Gordon A. Fenton, Auteur Article en page(s) : pp. 417-430 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Finite-element  method  Soil  consolidation  Probabilistic  methods  Coupling Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Coupled Biot consolidation theory was combined with the random finite-element method to investigate the consolidation behavior of soil deposits with spatially variable properties in one-dimensional (1D) and two-dimensional (2D) spaces. The coefficient of volume compressibility (mv) and the soil permeability (k) are assumed to be lognormally distributed random variables. The random fields of mv and k are generated by the local average subdivision method which fully takes account of spatial correlation, local averaging, and cross correlations. The generated random variables are mapped onto a finite-element mesh and Monte Carlo finite-element simulations follow. The results of parametric studies are presented, which describe the effect of the standard deviation, spatial correlation length, and cross correlation coefficient on output statistics relating to the overall “equivalent” coefficient of consolidation. It is shown that the average degree of consolidation defined by excess pore pressure and settlement are different in heterogeneous soils. The dimensional effect on the soil consolidation behaviors is also investigated by comparing the 1D and 2D results. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...] [article] Probabilistic analysis of coupled soil consolidation [texte imprimé] / Jinsong Huang, Auteur ; D. V. Griffiths, Auteur ; Gordon A. Fenton, Auteur . - pp. 417-430. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 3 (Mars 2010) . - pp. 417-430 Mots-clés : Finite-element  method  Soil  consolidation  Probabilistic  methods  Coupling Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Coupled Biot consolidation theory was combined with the random finite-element method to investigate the consolidation behavior of soil deposits with spatially variable properties in one-dimensional (1D) and two-dimensional (2D) spaces. The coefficient of volume compressibility (mv) and the soil permeability (k) are assumed to be lognormally distributed random variables. The random fields of mv and k are generated by the local average subdivision method which fully takes account of spatial correlation, local averaging, and cross correlations. The generated random variables are mapped onto a finite-element mesh and Monte Carlo finite-element simulations follow. The results of parametric studies are presented, which describe the effect of the standard deviation, spatial correlation length, and cross correlation coefficient on output statistics relating to the overall “equivalent” coefficient of consolidation. It is shown that the average degree of consolidation defined by excess pore pressure and settlement are different in heterogeneous soils. The dimensional effect on the soil consolidation behaviors is also investigated by comparing the 1D and 2D results. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...]

Probabilistic settlement analysis by stochastic and random finite-element methods / D. V. Griffiths in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 11 (Novembre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 11 (Novembre 2009) . - pp. 1629–1637 Titre : Probabilistic settlement analysis by stochastic and random finite-element methods Type de document : texte imprimé Auteurs : D. V. Griffiths, Auteur ; Gordon A. Fenton, Auteur Année de publication : 2009 Article en page(s) : pp. 1629–1637 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Foundation  settlementElasticityProbabilityFinite  element  methodStochastic  processes Résumé : The paper discusses finite element models for predicting the elastic settlement of a strip footing on a variable soil. The paper then goes on to compare results obtained in a probabilistic settlement analysis using a stochastic finite element method based on first order second moment approximations, with the random finite element method based on generation of random fields combined with Monte Carlo simulations. The paper highlights the deficiencies of probabilistic methods that are unable to properly account for spatial correlation. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000126 [article] Probabilistic settlement analysis by stochastic and random finite-element methods [texte imprimé] / D. V. Griffiths, Auteur ; Gordon A. Fenton, Auteur . - 2009 . - pp. 1629–1637. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 11 (Novembre 2009) . - pp. 1629–1637 Mots-clés : Foundation  settlementElasticityProbabilityFinite  element  methodStochastic  processes Résumé : The paper discusses finite element models for predicting the elastic settlement of a strip footing on a variable soil. The paper then goes on to compare results obtained in a probabilistic settlement analysis using a stochastic finite element method based on first order second moment approximations, with the random finite element method based on generation of random fields combined with Monte Carlo simulations. The paper highlights the deficiencies of probabilistic methods that are unable to properly account for spatial correlation. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000126

Return mapping algorithms and stress predictors for failure analysis in geomechanics / Jinsong Huang in Journal of engineering mechanics, Vol. 135 N° 4 (Avril 2009) 

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Stability assessment of slopes using different factoring strategies / Lysandros Pantelidis in Journal of geotechnical and geoenvironmental engineering, Vol. 138 N° 9 (Septembre 2012) 

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