Resumen
The structural analysis of historic masonry churches subject to earthquakes is commonly based on two distinct approaches: that of the global response to seismic actions and that of the local analysis of a priori pre-determined collapse mechanisms. This is a conventional decoupling of the structural problem due to the difficulty of addressing the seismic vulnerability of individual parts from the modelling of the whole. The aim of this work is to establish a link between the global behavior of the church and the assessment of the local mechanisms, re-evaluating the value of modal analysis to be associated with non-linear seismic assessment. With this aim, a two steps procedure is proposed, where: the first step is based on the detection of the main vibration modes of the whole building with identification of the structural bi-dimensional macro-elements that are responsible for the overall seismic vulnerability, while the second step, is based on the non-linear finite element analysis of the previously identified macro-elements, to evaluate the failure pattern caused by the earthquakes. The procedure will applied to the case study of the Casamari Gothic church in Veroli (Italy).