Search

International audience; The present paper deals with the influence of soil non-linearity, introduced by soil liquefaction, on the soil-foundation-structure interaction phenomena. Numerical simulations are carried out so as to study an improvement method to reduce the liquefaction potential in a sandy soil profile subjected to a shaking. The efficiency of the confinement walls in the mitigation of a liquefiable soil is showed. However, the intervention at the foundation soil modifies the dynamic characteristics of soil-structure system and it seems to be an unfavorable method from the structural point of view.

International audience

National audience; L'objectif de ce travail est d'étudier les effets du comportement non-linéaire du sol dans le cadre des méthodes de dimensionnement en déplacement. Pour cela, un ensemble des bâtiments en béton armé, conçus en respectant les recommandations et pratiques parasismiques usuelles, est utilisé de façon à étudier l'influence de l'interaction sol-structure non-linéaire sur leur réponse lors d'un séisme. Plusieurs simulations numériques dynamiques ont été conduites à fin d'étudier et à identifier le rôle de différents paramètres sur la réponse totale du système sol-structure. L'étude paramétrique comprend les paramètres mécaniques du sol, ceux de la structure, ainsi que les caractéristiques du mouvement sismique. ABSTRACT. This paper concerns the assessment of the effects of non-linear soil behaviour on the structural seismic demand evaluation. For this purpose, a set of reinforced concrete structures designed to be earthquake resistance in accordance with current criteria and methods is selected and the influence of non-linear dynamic soil-structure interaction on their seismic response is studied. Several non-linear dynamic analyses are performed in order to evaluate study the role of several parameters on the seismic performance. This parametric study concerns the mechanical parameters of the soil, of the structure and the earthquake motion characteristics.

International audience; When an earthquake occurs, the surrounding soil and the structural elements can exhibit non-linear behaviour. Usually, only non-linear behaviour of structural elements is evaluated. But, actually, the soil reaches the limit of its linear elastic behaviour before the structural elements. In general, the soil-structure interaction effects are assumed beneficial and thus ignored. Nevertheless, a more precise knowledge of the expected structural seismic response can allow reduce the cost of the structure and improve the earthquake engineering practice. This work concerns the assessment of the effects of non-linear soil behaviour on the seismic demand evaluation. For this purpose, numerical simulations of non-linear dynamic analysis are performed in order to study the role of several parameters on the seismic performance evaluation. This paper presents a summary of the main findings.

International audience; The purpose of this work is to investigate the role of the non-linear soil behavior on the structural dynamic response. Several soil-structure analyses are performed, assuming a linear-equivalent approximation for non-linear soil behaviour into a coupled FEM-BEM approach. A parametric study is carried out including the mechanical properties of both the soil foundation and the structure as well as the characteristics of the input motion. The differences found between the linear and the equivalent-linear dynamic SSI approach demonstrate the importance of a proper soil behaviour evaluation. A technique to derive the soil portion influenced significantly by the structure is presented. This limit defines a neighbourhood of the soil where non-linear behavior may be decisive for the global response of the structure. The results show the dependency of this influenced zone due to structure characteristics and giving a tool to establish when a most refined non-linear soil evaluation must be done.

Ce rapport présente les principes fondamentaux et les méthodes courantes de conception des bâtiments basees sur la notion de performance. L'extension de la méthode pour la prise en compte de facon approchée des effets d'interaction dynamique sol-structure est également presentée.