Documents disponibles écrits par cet auteur

Determination of the critical slip surface using artificial fish swarms algorithm / Y. M. Cheng in Journal of geotechnical and geoenvironmental engineering, Vol. 134 N°2 (Fevrier 2008) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°2 (Fevrier 2008) . - pp. 244–251 Titre : Determination of the critical slip surface using artificial fish swarms algorithm Type de document : texte imprimé Auteurs : Y. M. Cheng, Auteur ; Liang, L., Auteur ; S. C. Chi, Auteur Année de publication : 2008 Article en page(s) : pp. 244–251 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Slope  stability  Algorithms  Optimization  Finite  element  method  Slip Résumé : The writers have come across a difficult stability analysis problem where there are several “strong” local minima. Several well known heuristic global minimum methods fail to locate the global minimum for this case, and the writers finally adopt the artificial fish swarms algorithm to overcome this difficult problem. This optimization algorithm is demonstrated to be effective and efficient for normal problems. To illustrate the effectiveness of the proposed algorithm, three difficult examples are considered. The sensitivity of the proposed algorithm with respect to the parameters used for the global optimization algorithm will also be investigated in this paper. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A2%2824 [...] [article] Determination of the critical slip surface using artificial fish swarms algorithm [texte imprimé] / Y. M. Cheng, Auteur ; Liang, L., Auteur ; S. C. Chi, Auteur . - 2008 . - pp. 244–251. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 134 N°2 (Fevrier 2008) . - pp. 244–251 Mots-clés : Slope  stability  Algorithms  Optimization  Finite  element  method  Slip Résumé : The writers have come across a difficult stability analysis problem where there are several “strong” local minima. Several well known heuristic global minimum methods fail to locate the global minimum for this case, and the writers finally adopt the artificial fish swarms algorithm to overcome this difficult problem. This optimization algorithm is demonstrated to be effective and efficient for normal problems. To illustrate the effectiveness of the proposed algorithm, three difficult examples are considered. The sensitivity of the proposed algorithm with respect to the parameters used for the global optimization algorithm will also be investigated in this paper. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282008%29134%3A2%2824 [...]

Evaluation of interslice force function and discussion on convergence in slope stability analysis by the lower bound method / Y. M. Cheng in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 8 (Août 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 8 (Août 2010) . - pp. 1103-1113 Titre : Evaluation of interslice force function and discussion on convergence in slope stability analysis by the lower bound method Type de document : texte imprimé Auteurs : Y. M. Cheng, Auteur ; Z. H. Zhao, Auteur ; Y. J. Sun, Auteur Année de publication : 2010 Article en page(s) : pp. 1103-1113 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Slope  stability  analysis  Factor  of  safety  Interslice  force  function  Global  maximum  Lower  bound  theorem  Convergence Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : The interslice force function f(x) is a major assumption of the limit equilibrium method, which is important but has not been adequately considered in the past. In this paper, f(x) is taken as the control variable, and the upper and lower limits of the factor of safety for a general slope will be determined by a global optimization analysis. Based on this approach, f(x) will be determined and investigated. We demonstrate that f(x) cannot be arbitrarily assigned if a set of acceptable internal forces is required. The present approach can be presented practically as a lower bound approach with the advantage that failure to converge is virtually eliminated, which is not possible with all other existing “rigorous” methods. The “present proposal” attempts to answer several important questions in the basic theory of slope stability analysis, and provides a f(x) based on the lower bound approach statically admissible forces throughout the whole failure zone. Currently, different assumptions will give different factors of safety to the same problem, and this situation will be overcome by the use of the present proposal. The present proposal is also proven to give a result equal to the slip line solution for a simple footing on clay which is not possible for other classical slope stability methods, which has demonstrated that the applicability of the “present proposal” for general difficult problems. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i8/p1103_s1?isAuthorized=no [article] Evaluation of interslice force function and discussion on convergence in slope stability analysis by the lower bound method [texte imprimé] / Y. M. Cheng, Auteur ; Z. H. Zhao, Auteur ; Y. J. Sun, Auteur . - 2010 . - pp. 1103-1113. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 8 (Août 2010) . - pp. 1103-1113 Mots-clés : Slope  stability  analysis  Factor  of  safety  Interslice  force  function  Global  maximum  Lower  bound  theorem  Convergence Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : The interslice force function f(x) is a major assumption of the limit equilibrium method, which is important but has not been adequately considered in the past. In this paper, f(x) is taken as the control variable, and the upper and lower limits of the factor of safety for a general slope will be determined by a global optimization analysis. Based on this approach, f(x) will be determined and investigated. We demonstrate that f(x) cannot be arbitrarily assigned if a set of acceptable internal forces is required. The present approach can be presented practically as a lower bound approach with the advantage that failure to converge is virtually eliminated, which is not possible with all other existing “rigorous” methods. The “present proposal” attempts to answer several important questions in the basic theory of slope stability analysis, and provides a f(x) based on the lower bound approach statically admissible forces throughout the whole failure zone. Currently, different assumptions will give different factors of safety to the same problem, and this situation will be overcome by the use of the present proposal. The present proposal is also proven to give a result equal to the slip line solution for a simple footing on clay which is not possible for other classical slope stability methods, which has demonstrated that the applicability of the “present proposal” for general difficult problems. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i8/p1103_s1?isAuthorized=no

Flow pattern for a silo with two layers of materials with single or double openings / Y. M. Cheng in Journal of geotechnical and geoenvironmental engineering, Vol. 136 N° 9 (Septembre 2010) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 9 (Septembre 2010) . - pp. 1278-1286 Titre : Flow pattern for a silo with two layers of materials with single or double openings Type de document : texte imprimé Auteurs : Y. M. Cheng, Auteur ; Chau, K. T., Auteur ; L. J. Xiao, Auteur Année de publication : 2010 Article en page(s) : pp. 1278-1286 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Silo  Particle  flow  Discharging  Openings  Numerical  simulation Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : For the silo flow of two materials with contrasting strengths, an automatic separation without mixing of the materials is observed during drawing. In the present paper, the writers observe that a columniform funnel flow will appear in a silo with a single opening while a uniform flow will occur for a silo with a double opening. The classical and popular Janssen equation is hence less suitable for a silo with a single opening than for a silo with a double opening. The development of the arch action arising from the contact force is investigated through the distinct element analysis for the two different types of silo. It is also found that there are significant differences in the velocity and stress fields between the two different types of silo, which are worth consideration in the design of the silo and the recovery of the mineral ore. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i9/p1278_s1?isAuthorized=no [article] Flow pattern for a silo with two layers of materials with single or double openings [texte imprimé] / Y. M. Cheng, Auteur ; Chau, K. T., Auteur ; L. J. Xiao, Auteur . - 2010 . - pp. 1278-1286. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 9 (Septembre 2010) . - pp. 1278-1286 Mots-clés : Silo  Particle  flow  Discharging  Openings  Numerical  simulation Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : For the silo flow of two materials with contrasting strengths, an automatic separation without mixing of the materials is observed during drawing. In the present paper, the writers observe that a columniform funnel flow will appear in a silo with a single opening while a uniform flow will occur for a silo with a double opening. The classical and popular Janssen equation is hence less suitable for a silo with a single opening than for a silo with a double opening. The development of the arch action arising from the contact force is investigated through the distinct element analysis for the two different types of silo. It is also found that there are significant differences in the velocity and stress fields between the two different types of silo, which are worth consideration in the design of the silo and the recovery of the mineral ore. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i9/p1278_s1?isAuthorized=no

Laboratory test and particle flow simulation of silos problem with nonhomogeneous materials / Y. M. Cheng 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. 1754–1761 Titre : Laboratory test and particle flow simulation of silos problem with nonhomogeneous materials Type de document : texte imprimé Auteurs : Y. M. Cheng, Auteur ; Z. N. Liu, Auteur ; W. D. Song, Auteur Année de publication : 2009 Article en page(s) : pp. 1754–1761 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Laboratory  testsParticlesSolids  flowSimulationMining Résumé : Underground mine caving may induce collapse of the ground during ore caving, particularly when there is a loose material on top of the mine. In the present paper, a laboratory test is performed to model this mining problem which is followed by a particle flow simulation to simulate the interaction and movement between the two materials. For this nonhomogeneous problem, an interesting columniform channel for the loose material is formed during the drawing in both the experiment tests and the numerical modeling. The formation of this channel greatly affects the efficiency of ore drawing and the stability of the mine caving. The numerical modeling can be used for the optimization of ore drawing, ore drawing management and the prediction of ore loss and dilution indexes. The importance of the moisture content on ore drawing process and the efficiency of ore drawing are also investigated by both experimental and numerical tests, and useful results are found from the present study. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000125 [article] Laboratory test and particle flow simulation of silos problem with nonhomogeneous materials [texte imprimé] / Y. M. Cheng, Auteur ; Z. N. Liu, Auteur ; W. D. Song, Auteur . - 2009 . - pp. 1754–1761. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 11 (Novembre 2009) . - pp. 1754–1761 Mots-clés : Laboratory  testsParticlesSolids  flowSimulationMining Résumé : Underground mine caving may induce collapse of the ground during ore caving, particularly when there is a loose material on top of the mine. In the present paper, a laboratory test is performed to model this mining problem which is followed by a particle flow simulation to simulate the interaction and movement between the two materials. For this nonhomogeneous problem, an interesting columniform channel for the loose material is formed during the drawing in both the experiment tests and the numerical modeling. The formation of this channel greatly affects the efficiency of ore drawing and the stability of the mine caving. The numerical modeling can be used for the optimization of ore drawing, ore drawing management and the prediction of ore loss and dilution indexes. The importance of the moisture content on ore drawing process and the efficiency of ore drawing are also investigated by both experimental and numerical tests, and useful results are found from the present study. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000125