Empirical and mechanical analysis methods for seismic vulnerability assessment of clustered buildings of historical centres: A case study

Presently, in historical centres, it is very difficult to analyse buildings as independent structures, since they share the same boundary walls with adjacent structural units. These constructions of the building aggregate interact among themselves under seismic actions, so that their behaviour differs from that of the individual buildings considered as isolated structures. Therefore, it is emerging the need to assess seismic vulnerability of building aggregates. Thus, in this paper both simple empirical and mechanical refined vulnerability evaluation methods of masonry building aggregates are examined in general terms and illustrated in detail through the application on a case study in Mirandola, a district of Modena. On one hand, two empirical assessment methodologies, mainly based on the basic observational data of masonry constructions and properly calibrated on macro-element analysis results on a significant number of clustered buildings, are proposed taking properly into account the interactions among adjacent constructions. On the other hand, a mechanical analysis method at the individual building scale is also applied to evaluate more realistically the seismic behaviour of clustered structural units through the development of appropriate capacity curves.