1 THE ASSESSMENT OF THE SEISMIC BEHAVIOUR OF THE CATHEDRAL OF MODENA, ITALY Simonetta BARACCANI 1 , Stefano SILVESTRI 2 , Michele PALERMO 3 , Giada GASPARINI 4 , Tomaso TROMBETTI 5 , Antoine DIB 6 ABSTRACT The Cathedral of Modena, built at the end of the XI century, is one of the most important examples of the Romanesque art in Italy. In 1997, the monument was declared as “UNESCO World Heritage” site. Due to its cultural importance and with the aim of the conservation of the monument (symbol of the town), the structural behaviour of the Modena Cathedral has been deeply studied, during the last decade, through a multidisciplinary integrated approach. This approach is aimed at collecting all the information obtained from the different fields in order to develop structural analyses and, in particular, a vulnerability assessment of the actual state of the monument. The objective of this paper is to assess the seismic behavior of the monument through a multilevel approach, characterized by a number of different analyses. First, the dynamic properties of the monument (natural periods and mode shapes) have been identified through a natural frequency analysis performed on 3D finite element models. The fundamental periods are in the range of 0.25– 0.35 s. Then, specific hazard analyses have been developed in order to identify the most probable earthquake scenarios which (i) occurred in the past and (ii) is likely to occur in the future in the site of the monument. Both global (i.e. numerical simulations with reference to the finite models of the whole structure) and local analyses (i.e. local collapse mechanisms of the substructures) have been performed. The results of the local analyses reveal that the main local vulnerabilities are the facade mechanisms and the failures of the cross vaults. The results of the global analyses reveal vulnerabilities of the perimeter walls with respect to out-of-plane overturning. These numerical results have been confirmed by the experimental evidences of the damages observed after the recent 2012 “Emilia Earthquake”, which shook the North of Italy. INTRODUCTION Historical buildings are complex structures, built and modified in the course of centuries. Therefore, to perform structural (static or seismic) analyses consistent with the real structural behaviour is essential to have a thorough knowledge of these buildings. The Cathedral of Modena has been therefore studied 1 PhD., Department DICAM, University of Bologna, Italy, simonetta.baraccani2@unibo.it 2 Assistant Professor, Department DICAM, University of Bologna, Italy, stefano.silvestri@unibo.it 3 PhD., Department DICAM, University of Bologna, Italy, michele.palermo7@unibo.it 4 Assistant Professor, Department DICAM, University of Bologna, Italy, giada.gasparini4@unibo.it 5 Professor, Department DICAM, University of Bologna, Italy, tomaso.trombetti@unibo.it 6 PhD., Department DICAM, University of Bologna, Italy, antoine.dib2@unibo.it