Ricerc@Sapienza

The 2009 L’Aquila earthquake in southern Italy affected a rather large number of buildings, which experienced macroseismic intensities between V and IX on the Mercalli–Cancani–Sieberg scale. Almost sixty thousand unreinforced masonry constructions were officially inspected and almost half of them ended up losing their usability status temporarily, partially or completely, where the term usability refers to the suitability of a building for habitation or occupancy after a seismic event.

Predicting the usability of a building, i.e. its condition of being occupiable after a seismic event, is relevant both in a post-emergency situation and within a risk-reduction policy. In the past an empirical model was proposed, involving the computation of a usability index based on macroseismic intensity and on seven building parameters, combined by means of regression coefficients and weights. The statistical model was calibrated on data of about 60,000 buildings affected by the 2009 L’Aquila earthquake in Italy.

An overview of some simplified methods for assessing the seismic performance of ancient churches is presented in this paper. In particular, the simplified methods proposed by the current Italian directive containing the guidelines for assessment and reduction of cultural heritage seismic risk are analyzed. These methods have an increasing precision level and they may be applied as well in sequence at a different scale for screening and identifying the present priorities and, consequently, for designing the required interventions.

The protection of cultural heritage from seismic risk is an open issue due to the difficulties in finding technical solutions allowing a balance between their effectiveness and invasiveness. Among the available protection techniques, seismic isolation is one of the most suitable obtaining a significant performance improvement by acting on a limited portion of the structure. In this paper, it is shown an application of such technique on a reinforced concrete frame building cataloged as of historical interest by Italian Ministry of Cultural Heritage.

The seismic risk assessment of the historical and architectural heritage is, nowadays, a very relevant topic due the potential human and economic losses involved in case of global or partial collapse. In order to preserve the inestimable value of such heritage, the prevention and mitigation of the seismic risk is needed and it cannot be postponed.