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International audience; The destructive 1999 Chi-Chi earthquake (Mw 7.5) was the largest inland earthquake in Taiwan in the 20th century. Several observations witness the non-linear seismic soil response in sediments during the earthquake. In fact, large settlements as well as evidence of liquefaction attested by sand boils and unusual wet ground surface were observed at some sites. In this paper, we present a seismic response simulation performed with CyberQuake software on a site located within the Chang-Hwa Coastal Industrial Park during the 1999 Chi-Chi earthquake in Taiwan. A non-linear multi-kinematic dynamic constitutive model is implemented in the software. Computed NS, EW and UP ground accelerations obtained with this model under undrained and two-phase assumptions, are in good agreement with the corresponding accelerations recorded at seismic station TCU117, either for peak location, amplitudes or frequency content. In these simulations, liquefaction occurs between depths 1.3 and 11.3m, which correspond to the observed range attested by in place penetration tests and other liquefaction analyses. Moreover, the computed shear wave velocity profile is very close to post-earthquake shear wave velocity profile derived from correlations with CPT and SPT data. Finally, it is shown that in non-linear computations, even though a 1D geometry is considered, it is necessary to take into account the three components of the input motion.

International audience; The assessment of historical elements at risk from earthquake loading presents a number of differences from the seismic evaluation of modern structures, for design or retrofitting purposes, which is covered by existing building codes, and for the development of fragility curves, procedures for which have been extensively developed in the past decade. This article briefly discusses: the hazard framework for historical assets, including a consideration of the appropriate return period to be used for such elements at risk; the intensity measures that could be used to describe earthquake shaking for the analysis of historical assets; and available approaches for their assessment. We then discuss various unique aspects of historical assets that mean the characterisation of earthquake loading must be different from that for modern structures. For example, historical buildings are often composed of heterogeneous materials (e.g. old masonry) and they are sometimes located where strong local site effects occur due to: steep topography (e.g. hilltops), basin effects or foundations built on the remains of previous structures. Standard seismic hazard assessment undertaken for modern structures and the majority of sites is generally not appropriate. Within the PERPETUATE project performance-based assessments, using nonlinear static and dynamic analyses for the evaluation of structural response of historical assets, were undertaken. The steps outlined in this article are important for input to these assessments.

National audience; ABSTRACT. Earthquake shaking represents complex loading to the structure. It cannot be accurately characterized by a single parameter, e.g. peak ground acceleration. The goal of this work is to compare the role of various strong-motion parameters on the induced damage in the structure through numerical calculations. To this end, a robust structural model that can perform several dynamic calculations, with an acceptable cost, is required. The developed methodology is based on the use of structural elements with nonlinear behaviour of damage mechanics and plasticity type. The damage level of a typical reinforced concrete structure is evaluated by the use of nonlinear numerical calculations. The effect of numerous ground-motion parameters on the computed damage is analyzed and discussed. A set of weakly-correlated parameters are chosen that characterize different aspects of the shaking. Natural accelerograms were chosen based on a consideration of the magnitude-distance ranges of design earthquakes. It is expected that an increase from one to two or three groundmotion parameters would lead to a significant reduction in the scatter in the fragility curve, which when more than one parameter is used will be a surface. RÉSUMÉ. Le mouvement sismique applique un chargement complexe aux structures. Un seul paramètre, e.g. " PGA ", ne peut pas caractériser correctement ce chargement. L'objectif de ce travail est d'évaluer le rôle de plusieurs paramètres caractérisant un séisme sur le niveau de dégradation des structures. Pour y parvenir, il est essentiel de disposer de modèles fiables et robustes nous permettant de réaliser plusieurs calculs de structures avec un coût limité. La méthodologie développée s'appuie sur l'emploi d'éléments de structure capables de tirer profit des lois de comportement non-linéaires de type mécanique de l'endommagement et plasticité. Les simulations sont réalisées à l'aide d'accélérogrammes naturels ayant des caractéristiques variées et imposées suivant les trois directions de l'espace. Ces études permettent d'estimer les niveaux d'endommagement des structures en béton armé pour différentes intensités de l'action sismique. Lors des simulations E.F. réalisées sur un modèle d'un bâtiment R+7 les effets de plusieurs paramètres du mouvement sismique sur l'endommagement ont été analysés. Grâce à deux ou trois paramètres caractérisant l'action sismique, nous espérons diminuer significativement la dispersion des résultats des études de vulnérabilité sismique du bâti.