SEISMIC RESPONSE OF REINFORCED CONCRETE BEARING WALLS, 2D AND 3D F.E. SIMPLIFIED ANALYSIS Frédéric Ragueneau 1 , Géraldine Casaux 2 , and Jacky Mazars 3 , Member ASCE ABSTRACT This paper deals with the behavior of reinforced concrete bearing walls subjected to seismic loading. The presentation focuses on the numerical tools dedicated to nonlinear transient simplified analysis allowing parametrical studies. In a first step, the multifibers beam approach is presented as well as the local nonlinear constitutive equations. Comparisons between experimental results and numerical computation for 2-D and 3-D case-study are presented. Keywords: seismic engineering, constitutive relations, transient analysis, simplified analysis INTRODUCTION Concerning the study of load bearing walls commonly used in France. Research programs (experiments and modeling) have been carried out on the topic focusing around the realization of experiments on mock-ups (scale 1/3rd) performed on a seismic shaking table. The main purpose of this experimental program consists in demonstrating the ability of reinforced concrete bearing walls to bear seismic loading. The specific design concept is based on the multifuse principle favoring rupture occurrence at several storeys for a slightly reinforced concrete wall. This kind of design leads to lower percentages of reinforcements with their optimized distribution which may generate a wider crack pattern allowing the dissipation of great amounts of energy, and as a consequence, a vertical rising of the masses resulting in energy transformation (from kinematic to potential). Thus ductility is obtained thanks to this particular means to dissipate the earthquake input energy. The studied structure is a mock-up of a building composed of two parallel reinforced concrete load-bearing walls. The behavior of those under the effect of seismic loadings remains a delicate topic with many regards. Indeed, the three principal elements of a calculation must be taken into 1 Laboratoire de Mécanique et Technologie, ENS-Cachan, 94235 France. E-mail: ragueneau@lmt.ens-cachan.fr 2 Laboratoire de Mécanique et Technologie, ENS-Cachan, 94235 France. E-mail: casaux@lmt.ens-cachan.fr 3 L3S - Institut National Polytechnique de Grenoble, BP53, F-38041 Grenoble – E-mail: Jacky.Mazars@inpg.fr