Seismic Vulnerability Assessment of Churches Affected by the 2012 Emilia – Romagna Earthquake: Comparison among Different Approaches

This paper discusses the seismic assessment of a set of 23 churches placed in the city of Bondeno (district of Ferrara) within the Emilia – Romagna region of Italy. The churches analysed were hit by the 2012 earthquake, which caused many victims and damages to both industrial and historical structures. Specifically, the contribution is about a comparison among three damage indices derived from three different approaches and methods of analysis. The first index resulted from the application of a simplified mechanical model proposed by the Italian Guidelines for Cultural Heritage (IGCH). The second damage indicator was derived from the direct observation of the damaged churches from filling the AeDES form used in the earthquake post-emergency phase. Finally, the last damage parameter came from the kinematic analyses applied to the different church macro-elements aimed at evaluating the accelerations activating the local mechanisms. The final goal of the comparison is to evaluate the reliability of the simplified mechanical model and whether it could be used for a quick estimation of the damage to churches affected by seismic events. The geometrical information about the type of system (i.e. with rectangular or central layout), the construction period and the structural properties (i.e. materials used for vertical and horizontal structures) were achieved through filling the CARTIS form appropriately conceived by the PLINIVS research centre and the Italian Civil Protection Department for typological-structural characterization of these construction type. The comparison among the three indices was herein conducted through the modelling of a case study, on which kinematic analyses based on the available data were carried out. The achieved results gave positive results on the use of the easy method to foresee the church damages, even if further analyses must be done to validate its reliability.