Influence of infill panels and floor system in the fragility analysis of existing rc buildings: a case study

In the last few years, the study of the seismic fragility of existing Reinforced Concrete (RC) buildings has been the object of a wide interest within the scientific community, especially after the experiences provided by recent hazardous events, which have shown the vulnerability of the existing RC building stock. The recent studies about this topic have shown that the probabilistic approach of Performance Based Earthquake Engineering (PBEE) is the most suitable methodology for taking into account the different sources of uncertainty in fragility analysis, considering both the nature of the seismic demand and the problems related to the incomplete knowledge. For an accurate probabilistic seismic fragility estimation, a fundamental aspect is to consider the contribution of all the elements that constitute the building system, such as the secondary structural (floor system) and non-structural elements (infill panels). In this paper, the focus is aimed on the investigation of the role of secondary and non-structural elements in the evaluation of fragility curves of existing RC buildings. In particular, a real case study, representative of the typical existing school buildings of the Southern Italy, is analysed and discussed.