Damages to masonry churches after 2016–2017 Central Italy seismic sequence and definition of fragility curves

The paper presents a detailed report on a large sample of masonry churches damaged by the 2016–2017 Central Italy seismic sequence. The first part of the work analyses the seismic sequence to give an overview of the occurred events in terms of both ground motion parameters and macro-seismic intensities. The surveyed data are organized into a database made, to date, of 990 cases, which represent almost one-fourth of the whole surveys performed during the emergency phase. Such a significant statistical sample was used to carry out a regional scale typological analysis in order to identify the most recurrent typologies of churches present in Central Italy. The analysis of the observed damage and usability outcomes allowed drawing some conclusions on the behaviour of the inspected churches under the 2016–2017 seismic sequence. The collected data were used to create damage probability matrixes for homogeneous classes of churches at different damage levels and, successively, to implement the corresponding fragility curves in terms of PGA.