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Installation and axial pullout of suction caissons / L. F. Gonzalo Vasquez 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. 1137-1147 Titre : Installation and axial pullout of suction caissons : numerical modeling Type de document : texte imprimé Auteurs : L. F. Gonzalo Vasquez, Auteur ; Dilip R. Maniar, Auteur ; John L. Tassoulas, Auteur Année de publication : 2010 Article en page(s) : pp. 1137-1147 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Caisson  Suction  Anchor  Offshore  Penetration  Porous  medium  Porous  media  Friction  Consolidation  Setup  Pullout  Axial  capacity  Finite  element Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : We outline the development of a computational procedure for finite-element analysis of suction-caisson behavior, highlighting its unique features and capabilities. The procedure is based on a description of clayey soil as a two-phase medium: a water-filled porous solid. Nonlinear behavior of the solid phase is represented by means of a bounding-surface plasticity model. An algorithm is developed for frictional contact in terms of effective normal stress. Furthermore, a special remeshing scheme is introduced facilitating the simulation of the installation process, tracking the caisson penetration path and avoiding numerical complications in the vicinity of the caisson-soil interfaces. To illustrate the use of the proposed computational procedure and examine its validity, complete simulations of available laboratory tests on model suction caissons are conducted. Results are presented and discussed for test-bed preparation (consolidation) followed by caisson installation by self-weight and suction, setup (reconsolidation), and axial pullout. The overall agreement between computations and measurements is good. Possible improvements are identified and recommendations are made regarding future studies. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i8/p1137_s1?isAuthorized=no [article] Installation and axial pullout of suction caissons : numerical modeling [texte imprimé] / L. F. Gonzalo Vasquez, Auteur ; Dilip R. Maniar, Auteur ; John L. Tassoulas, Auteur . - 2010 . - pp. 1137-1147. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 136 N° 8 (Août 2010) . - pp. 1137-1147 Mots-clés : Caisson  Suction  Anchor  Offshore  Penetration  Porous  medium  Porous  media  Friction  Consolidation  Setup  Pullout  Axial  capacity  Finite  element Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : We outline the development of a computational procedure for finite-element analysis of suction-caisson behavior, highlighting its unique features and capabilities. The procedure is based on a description of clayey soil as a two-phase medium: a water-filled porous solid. Nonlinear behavior of the solid phase is represented by means of a bounding-surface plasticity model. An algorithm is developed for frictional contact in terms of effective normal stress. Furthermore, a special remeshing scheme is introduced facilitating the simulation of the installation process, tracking the caisson penetration path and avoiding numerical complications in the vicinity of the caisson-soil interfaces. To illustrate the use of the proposed computational procedure and examine its validity, complete simulations of available laboratory tests on model suction caissons are conducted. Results are presented and discussed for test-bed preparation (consolidation) followed by caisson installation by self-weight and suction, setup (reconsolidation), and axial pullout. The overall agreement between computations and measurements is good. Possible improvements are identified and recommendations are made regarding future studies. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v136/i8/p1137_s1?isAuthorized=no

Installation of torpedo anchors / Mohammad S. Raie in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N° 12 (Décembre 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 12 (Décembre 2009) . - pp. 1805–1813 Titre : Installation of torpedo anchors : numerical modeling Type de document : texte imprimé Auteurs : Mohammad S. Raie, Auteur ; John L. Tassoulas, Auteur Année de publication : 2010 Article en page(s) : pp. 1805–1813 Note générale : Génotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : AnchorsPenetrationSoilViscous  flowComputational  fluid  dynamics  techniqueNumerical  models Résumé : Torpedo anchors are used as foundations for mooring deep-water offshore facilities, including risers and floating structures. They are cone-tipped cylindrical steel pipes ballasted with concrete and scrap metal and penetrate the seabed by the kinetic energy they acquire during free fall through the water. A mooring line is usually connected at the top of the anchor. The design of such anchors involves estimation of the embedment depth as well as short-term and long-term pullout capacities. This paper describes the development of a computational procedure that leads to prediction of torpedo-anchor embedment depth. The procedure relies on a computational fluid dynamics (CFD) model for evaluation of the resisting forces on the anchor. In the model, the soil is represented as a viscous fluid and the procedure is applied to axially symmetric penetration of the seabed. The CFD approach provides estimates of not only the embedment depth but the pressure and shear distributions on the soil-anchor interface and in the soil. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000159 [article] Installation of torpedo anchors : numerical modeling [texte imprimé] / Mohammad S. Raie, Auteur ; John L. Tassoulas, Auteur . - 2010 . - pp. 1805–1813. Génotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N° 12 (Décembre 2009) . - pp. 1805–1813 Mots-clés : AnchorsPenetrationSoilViscous  flowComputational  fluid  dynamics  techniqueNumerical  models Résumé : Torpedo anchors are used as foundations for mooring deep-water offshore facilities, including risers and floating structures. They are cone-tipped cylindrical steel pipes ballasted with concrete and scrap metal and penetrate the seabed by the kinetic energy they acquire during free fall through the water. A mooring line is usually connected at the top of the anchor. The design of such anchors involves estimation of the embedment depth as well as short-term and long-term pullout capacities. This paper describes the development of a computational procedure that leads to prediction of torpedo-anchor embedment depth. The procedure relies on a computational fluid dynamics (CFD) model for evaluation of the resisting forces on the anchor. In the model, the soil is represented as a viscous fluid and the procedure is applied to axially symmetric penetration of the seabed. The CFD approach provides estimates of not only the embedment depth but the pressure and shear distributions on the soil-anchor interface and in the soil. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000159