Documents disponibles écrits par cet auteur

On the variable mesh finite element analysis of unconfined seepage problems / A. Cividini in Géotechnique, Vol. 39 N°2 (Juin 1989) 

Public ISBD [article]  in Géotechnique > Vol. 39 N°2 (Juin 1989) . - pp. 251 –267 Titre : On the variable mesh finite element analysis of unconfined seepage problems Type de document : texte imprimé Auteurs : A. Cividini, Auteur ; G. Gioda, Auteur Année de publication : 2007 Article en page(s) : pp. 251 –267 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Seepage  Finite  elements  Computation  Keywords  Time  dependence Résumé : Some drawbacks affecting the variable mesh finite element solution of unconfined flow problems are discussed and a procedure is suggested aimed at avoiding them in steady state and transient analyses. In particular, it is shown that the results of standard algorithms often used in practice may present spurious oscillations of the phreatic surface in the vicinity of the intersection with a pervious boundary exposed to the atmosphere. They may become exceedingly large when a limited number of elements is adopted in the mesh, and in some cases lead to non-correct final (steady state) configurations of the free surface. In order to eliminate this negative effect from the finite element analysis, a simple criterion is suggested based on an algorithm for non-linear function minimization. Some applications of this technique are presented to two- and three-dimensional unconfined problems. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.1989.39.2.251 [article] On the variable mesh finite element analysis of unconfined seepage problems [texte imprimé] / A. Cividini, Auteur ; G. Gioda, Auteur . - 2007 . - pp. 251 –267. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 39 N°2 (Juin 1989) . - pp. 251 –267 Mots-clés : Seepage  Finite  elements  Computation  Keywords  Time  dependence Résumé : Some drawbacks affecting the variable mesh finite element solution of unconfined flow problems are discussed and a procedure is suggested aimed at avoiding them in steady state and transient analyses. In particular, it is shown that the results of standard algorithms often used in practice may present spurious oscillations of the phreatic surface in the vicinity of the intersection with a pervious boundary exposed to the atmosphere. They may become exceedingly large when a limited number of elements is adopted in the mesh, and in some cases lead to non-correct final (steady state) configurations of the free surface. In order to eliminate this negative effect from the finite element analysis, a simple criterion is suggested based on an algorithm for non-linear function minimization. Some applications of this technique are presented to two- and three-dimensional unconfined problems. ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.1989.39.2.251