Static and seismic analysis of a historic masonry building in San Pio delle Camere

In February 2021, in San Pio delle Camere, on the Navelli plateau south-east of L'Aquila, a masonry building collapsed suddenly, after repair work had just begun on the damage caused by the 2009 earthquake. The current study, after a detailed examination of all the design documentation and the comparison of the post-earthquake damage with the results of the analysis on the model, finding an excellent correspondence, went to research the possible causes of the structural collapse, which occurred in static conditions. The masonry texture was then analysed, consisting of unworked natural stones of medium-small size bound by poor quality mortar, parameterising the mechanical characteristics with in situ tests, the Masonry Quality Index and the values proposed in NTC 2018. Then, the analysis of the global model lead to the verification of the complexity of the aggregate induced greater pressures, and consequent deformations, precisely in the walls from which the collapse originated. With these assumptions, and from the evidence of the presence of a modest void in an internal facing, the study of the local mechanism was deepened, arriving at the presumption of the possible minimum dimensions of such a cavity and how this, even if minimal, could have been the cause if concomitant with the degradation of the bonding mortar induced by the absence of maintenance and the loss of even minimal resistance capacities.