Seismic vulnerability overview of historical masonry churches in Europe

This paper presents a contribution for the safety assessment of historical masonry churches located in earthquake prone areas. Six different simplified safety indexes (three in-plane and three out-of-plane) are analyzed, taking into account a large sample of forty-four European churches. The sample of buildings has been organized according to the seismic hazard. All inplane indexes are compared with proposed thresholds, in order to detect cases in serious risk and to define priority of studies. These indexes do not present a clear tendency with respect to seismicity, though a slightly trend can be established. Even for low seismicity areas, in-plane indexes are often violated. Based on the results achieved, a proposal for the usage of the simplified indexes is made. The analysis of the out-of-plane indexes illustrates that a logical common trend with respect to seismicity can be found, which points out the possibility of defining threshold criteria, as used for the in-plane indexes. The results indicate that valuable information can be obtained from simplified methods, with respect to performing a first screening and to prioritizing further deeper investigations.