Simplified Seismic Vulnerability of Several Basilica-Type Churches

Among the cultural heritage masonry structures, basilica-type churches are complex structures often characterized by an open plan layout with slender perimeter walls. Their seismic vulnerability, as already discussed in previous studies, and as once more recently demonstrated by the dramatic recent earthquakes in Italy, is frequently enhanced by the absence of adequate connections between the various parts that constitute the structural complex, together with the presence of thrusting horizontal elements. In this paper, several basilica-type churches located in Tuscany Region have been analyzed with simplified methods, in order to evaluate their main geometric characteristics and their specific seismic vulnerabilities. The simplified methods are the Simplified Indexes proposed by Lourenço and Roque (2006) and the LV1 method, introduced by the Italian guidelines (DPCM 2011). These methods, indeed, are mainly aimed at evaluating a comparative ranking risk between similar structures to be intended as a useful tool for the public administrations for highlighting the most critical situations in the territory and to establish priorities for future investigations and/or interventions.