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In recent decades, different macro-models have been proposed for simulating the behaviour of concrete shear walls because of their significant role in the seismic performance of urban buildings. The ability of Timoshenko's beam theory to evaluate the behaviour of slender and moderate-aspect-ratio concrete shear walls was evaluated in this work. For this purpose, a non-linear displacement-based Timoshenko fibre element was first added to OpenSees software. A new constitutive model based on modified compression field theory was used for the stress–strain relationship of the materials. To validate the element and the materials used, the results of the numerical model were compared with a set of laboratory tests of concrete shear walls subjected to cyclic and seismic loads (shaking table tests). Evaluation of the numerical model and the experimental results revealed that the analysis procedure used to model the reinforced concrete walls predicted their overall and local responses with acceptable accuracy. It can thus be used as a reliable tool for the analysis of slender and moderate-aspect-ratio concrete shear walls.

IntroductionSeismic provisions in current building codes and standards include rules for design of structures using nonlinear response history analysis in some conditions. Due to the lack of recorded data for the design level earthquakes (which are usually rare events), it is critical to develop systematic methods and useful tools to select and modify from current ground motion databases to provide a group of earthquake motions that can realistically represent important aspects of the design motion controlling the nonlinear response of civil engineering facilities [1]. The best method for selecting and scaling ground motions will depend on the type of assessment being performed. ATC-58-1 identifies three types of performance assessment: intensity, scenario, and time-based. Intensity-based assessments are the most common of the three types and compute the response of a building and its components for a specified intensity of ground shaking (this approach is the focus of this paper). A scenario-based assessment computes the response of a building to a user specified earthquake event, which is typically defined by earthquake magnitude and the distance between the earthquake source and the building site. A risk-based (referred to as time-based assessment in ATC-58-1) assessment provides information on response over a period of time (e.g., annual rates). This is the most comprehensive type of assessment and involves a number of intensity-based assessments over the range of ground motion levels of interest [2]. Despite the scenario-based assessment which computes the response of a building based on a specific earthquake event, intensity and time-based assessments have been conducted subjecting to a group of records. Time-based assessment acquires information of all occurred earthquakes which have been utilized to adjust hazard curve of the assessed region; so, as much as records could be provided, the confidence level will promote, so many researchers attempts to enlarge records category to reduce record-by-record variations incorporated in this type of assessment. However, intensity-based assessment deal with number of records represented by intensity measures (IM), like peak ground acceleration, spectral acceleration on fundamental period of the model or etc., which are scaled associated to the intensity assumed target spectrum. Therefore, although enlarge-

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