Appraisal of masonry infill walls effects in the seismic response of RC framed buildings: A case study

In the last few decades, the scientific community has been extensively involved in the investigation about the interaction between infill masonry walls and RC frames in the seismic structural behavior, both for new and for existing buildings. With respect to this issue, some extensions of the N2 Method have been proposed in order to evaluate the contribution of masonry infill to the structural response. This paper presents an extensive case study regarding the analysis of an existing RC framed building located in a high seismic risk area in Calabria (Southern Italy), for which the project, dated back to the early ‘70s, provided only the presence of vertical loads. In order to collect the data required for the application of the safety assessment procedure and achieve the necessary knowledge level, a broad experimental test campaign was performed on the building in order to assess the condition and quality of both RC elements and infill walls. A number of non-linear static (pushover) analyses were performed on proper structural models of the building, considering both the bare framed structure and the infilled one, in order to appraise the influence of infill walls on the failure mechanisms. In particular, a sensitivity analysis was performed by assigning different Partial Safety Factors (PSF) to the mechanical parameters of infill walls, in order to investigate their effect on the overall structural response of the building.