Seismic vulnerability assessment of historic towns, the case of Benevento in Italy

Masonry buildings are in general characterized by a wide variability of parameters that influence the structural behavior both under vertical and horizontal loads. However, a lot of historical centers in Italy, constructed in coeval periods and with similar building techniques and materials, present comparable typological characteristics. Based on this consideration, the historical center of Benevento has been chosen for carrying out large scale in situ relieves (more than 220 buildings have been examined) in order to individuate frequent building typologies and to fix the ranges of variability for the main geometrical and mechanical parameters. These considerations led to simulate 96 prototypes. Then, a procedure for assessing the seismic vulnerability was developed by carrying out push-over analyses for all the 96 simulated prototypes by examining their behavior in terms of load-displacement curve. Successively, the distribution of damage in each class of buildings has been estimated through the construction of 'fragility curves' in terms of PGA. Such curves have been used in the present paper for assessing the seismic vulnerability of the real buildings in the historical center of Benevento for several damage levels and under different design seismic actions.