A comparative study on a 2-storey benchmark case study through nonlinear seismic analysis

This paper presents the comparison of the results of nonlinear static analyses performed on a simple masonry building with different computer programs that work within the Equivalent Frame Modelling approach. The activity described in this paper is part of a wider research program carried out within the ReLUIS 2014-2018 project (founded by the Italian Department of Civil Protection) whose main objectives are: to support the professional engineers in acquiring a proper awareness in the use of software packages available for the seismic assessment; to provide them analytical tools and a methodological approach for the critical analysis of the obtained results. Within this context, the paper is focused to one of the benchmark case studies conceived in this project that consists in a single-unit two-story masonry building with rigid diaphragms. Seven different configurations have been designed varying the layout of the openings on the four bearing walls and the structural details. The modelling process of the building has been faced by adopting, when possible, common assumptions in order to facilitate the interpretation of the differences in the results obtained by the different software. Comparison of the results involves different aspects: the global scale response in terms of pushover curve; the damage pattern predicted; checks at local scale in terms of generalized forces. In general, the achieved results show a very good agreement when configurations are close to the shear-type idealization while increasing scattered results arise in case of configurations characterized by weak spandrels (i.e. without tensile resistant elements coupled).