Documents disponibles écrits par cet auteur

Effects of particle crushing in stress drop-relaxation experiments on crushed coral sand / Poul V. Lade 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. 500-509 Titre : Effects of particle crushing in stress drop-relaxation experiments on crushed coral sand Type de document : texte imprimé Auteurs : Poul V. Lade, Auteur ; Jungman Nam, Auteur ; Carl D. Liggio Jr., Auteur Article en page(s) : pp. 500-509 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Creep  Granular  materials  Sand  Soil  properties  Stress  relaxation  Time  dependence  Triaxial  tests Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Stress relaxation and stress drop-relaxation tests have been performed to complement a test series performed to study strain rate, creep, and stress drop-creep effects on crushed coral sand. Drained experiments with constant effective confining pressure of 200 kPa were performed in which triaxial specimens of crushed coral sand were loaded to initial stress differences of 500, 700, and 900 kPa, followed by stress drops of 0, 100, 200, 300, and 400 kPa at which points the axial strains were kept constant while the axial stress relaxation and the volumetric strains were observed. The stress drops produced delays in initiation of stress relaxation that were proportional with the magnitudes of the stress drops. The experiments show that sands do not exhibit classic viscous effects, and their behavior is indicated as “nonisotach,” while the typical viscous behavior of clay is termed “isotach.” Thus, there are significant differences in the time-dependent behavior patterns of sands and clay. A mechanistic picture of time effects in sands is proposed. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...] [article] Effects of particle crushing in stress drop-relaxation experiments on crushed coral sand [texte imprimé] / Poul V. Lade, Auteur ; Jungman Nam, Auteur ; Carl D. Liggio Jr., Auteur . - pp. 500-509. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 3 (Mars 2010) . - pp. 500-509 Mots-clés : Creep  Granular  materials  Sand  Soil  properties  Stress  relaxation  Time  dependence  Triaxial  tests Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : Stress relaxation and stress drop-relaxation tests have been performed to complement a test series performed to study strain rate, creep, and stress drop-creep effects on crushed coral sand. Drained experiments with constant effective confining pressure of 200 kPa were performed in which triaxial specimens of crushed coral sand were loaded to initial stress differences of 500, 700, and 900 kPa, followed by stress drops of 0, 100, 200, 300, and 400 kPa at which points the axial strains were kept constant while the axial stress relaxation and the volumetric strains were observed. The stress drops produced delays in initiation of stress relaxation that were proportional with the magnitudes of the stress drops. The experiments show that sands do not exhibit classic viscous effects, and their behavior is indicated as “nonisotach,” while the typical viscous behavior of clay is termed “isotach.” Thus, there are significant differences in the time-dependent behavior patterns of sands and clay. A mechanistic picture of time effects in sands is proposed. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JGGEFK&smode=strres [...]

Strain rate, creep, and stress drop-creep experiments on crushed coral sand / Poul V. Lade in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 7 (Juillet 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 7 (Juillet 2009) . - pp. 941–953 Titre : Strain rate, creep, and stress drop-creep experiments on crushed coral sand Type de document : texte imprimé Auteurs : Poul V. Lade, Auteur ; Carl D. Liggio Jr., Auteur ; Jungman Nam, Auteur Année de publication : 2009 Article en page(s) : pp. 941–953 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Creep  Granular  materials  Sand  Soil  properties  Strain  rate  Time  dependence  Triaxial  tests Résumé : The part of sand behavior that is affected by time, such as creep, relaxation, and loading rate effects are not similar to those observed for clay. To throw more light on the time effects in sand, many series of drained triaxial compression experiments have been performed on crushed coral sand. These tests were all performed with a constant effective confining pressure of 200kPa . The test series included experiments with specimens loaded at five different strain rates with a 256-fold ratio between the extreme rates, tests with sudden changes in strain rate from slow to fast and vice versa, and tests in which axial and volumetric creep strains were observed at stress differences of 500, 700, and 900kPa . Creep creates structuration and this has to be overcome to produce further plastic straining. Experiments were also performed in which the stress difference was dropped quickly from three different values of 500, 700, and 900kPa followed by creep. In these stress drop-creep tests five different magnitudes of stress drops were employed: 0, 100, 200, 300, and 400kPa . The results involving conventional creep effects and stress drop-creep effects are presented and analyzed. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000067 [article] Strain rate, creep, and stress drop-creep experiments on crushed coral sand [texte imprimé] / Poul V. Lade, Auteur ; Carl D. Liggio Jr., Auteur ; Jungman Nam, Auteur . - 2009 . - pp. 941–953. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 7 (Juillet 2009) . - pp. 941–953 Mots-clés : Creep  Granular  materials  Sand  Soil  properties  Strain  rate  Time  dependence  Triaxial  tests Résumé : The part of sand behavior that is affected by time, such as creep, relaxation, and loading rate effects are not similar to those observed for clay. To throw more light on the time effects in sand, many series of drained triaxial compression experiments have been performed on crushed coral sand. These tests were all performed with a constant effective confining pressure of 200kPa . The test series included experiments with specimens loaded at five different strain rates with a 256-fold ratio between the extreme rates, tests with sudden changes in strain rate from slow to fast and vice versa, and tests in which axial and volumetric creep strains were observed at stress differences of 500, 700, and 900kPa . Creep creates structuration and this has to be overcome to produce further plastic straining. Experiments were also performed in which the stress difference was dropped quickly from three different values of 500, 700, and 900kPa followed by creep. In these stress drop-creep tests five different magnitudes of stress drops were employed: 0, 100, 200, 300, and 400kPa . The results involving conventional creep effects and stress drop-creep effects are presented and analyzed. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000067