Seismic analysis of RC buildings by modeling floor deformability and infill walls

In the last few years, the assessment of existing RC buildings has been a primary focus of interest within the scientific community, especially in areas characterized by high seismic hazard and presence of buildings vulnerable because of the structural design or materials’ decay. In order to study the response of buildings under seismic actions, it is necessary to study 3D finite element (FE) models, which simulate the structural behavior. The accuracy of results depends by the initial hypotheses assumed for the numerical model, such as the rigid floor assumption, which allows reducing the Degrees of Freedoms of the structure. As shown in the literature and in modern codes, this hypothesis is not always valid, especially when buildings are characterized by irregular geometries or distribution of mass and stiffness. The aim of the paper is to assess the influence of the rigid floor hypothesis on the accuracy of results provided by 3D FE models. This is made by an accurate modeling of the floor system and by considering the variation of the vertical resistant system (addition of RC walls) and non-structural vertical elements (infill walls). The influence of these parameters on the global response is discussed for a real case study.