Fragility curves for URM buildings typologies in a historical center of Central Italy: the influence of seismic input

It is well known that unreinforced masonry building typologies (URM) of Italian historical centers are particularly vulnerable toward out-of-plane mechanisms (Sorrentino et al., 2019), as even highlighted by recent seismic events of Central Italy (2016-2017). A first step toward prevention and mitigation actions, aimed to safeguard the building heritage of historical centers, is certainly represented by the prediction, at a large scale, of the potential damages that buildings may suffer after a seismic event of a certain intensity. The fragility curves can provide an adequate and useful tool for this purpose, as evidenced by numerous studies available in the current literature (Cima et al., 2021a, 2021b, 2021c; Zucconi et al., 2021). The aim of this research is, then, to propose an approach for evaluating fragility curves of unreinforced masonry building typologies typical of a given geographical area with regard to the most probable out-of-plane mechanisms. The detection of these typologies is based on the data collected within the CARTIS project (DPC/ReLUIS 2019-2021) and reported in the CARTIS database (Zuccaro et al., 2016). In the proposed procedure, both spectral-shapes derived by the Italian code and combinations of natural spectra, have been considered in order to analyze their influence on the fragility curves. The procedure is applied to the building typologies detected in the historical center of Sora in the province of Frosinone (Lazio Region), a medium size town of Central Italy assumed by the authors as case study.