Modelisation de l'intéraction sol-structure en utilisant comportement du sol linéaire équivalent dans la méthode de structuration

• Auteur / Autrice : Dimitris Pitilakis
• Direction : Arézou Modaressi
• Type : Thèse de doctorat
• Discipline(s) : Génie parasismique
• Date : Soutenance en 2006
• Etablissement(s) : Châtenay-Malabry, Ecole centrale de Paris
• Partenaire(s) de recherche : Laboratoire : Laboratoire de mécanique des sols, structures et matériaux (Gif-sur-Yvette, Essonne ; 1998-2021)

Mots clés

Mots clés contrôlés

Fondations (construction)

Impédance mécanique

Interaction sol-structure

Mots clés libres

Modèle linéaire équivalent

Sous-structures dynamiques

Résumé

A numerical procedure, coded into a numerical code (MISS3D-EqL), is developed to accommodate for the effects of the nonlinear soil behavior on the soil-structure interaction (SSI) using an equivalent linear approach. Equivalent linear behavior is assumed for the soil, while the response of the structure to the ground shaking and its effects on the soil are properly taken into account using the substructure method. The proposed procedure is validated against other numerical software and experimental means, such as shaking table and centrifuge tests. The effects of the equivalent linear soil behavior on the soil-structure system response are clearly demonstrated by analyses of representative case studies. A recursive analysis of typical soil profiles and infrastructures is performed to reveal the further softening of the system and the increased energy dissipation, compared to the linear case, due to the equivalent linear soil behavior. Special emphasis is given to the estimation of the foundation dynamic impedance functions. Dynamic stiffness and radiation dashpot coefficients are estimated for typical footings resting on typical soil profiles with equivalent linear behavior. The effects of the nonlinear soil behavior on the dynamic coefficient are shown compared to the linear elastic case. The dynamic stiffness coefficient decreases with increasing input acceleration amplitude, with decreasing soil shear wave velocity and with decreasing soil shear modulus, while it depends on the frequency content of the earthquake. The radiation dashpot coefficient is unaffected by the nonlinear soil behavior for most practical applications.