CALIBRATION OF SEISMIC VULNERABILITY INDEX FOR MASONRY CHURCHES BASED ON AHP INCLUDING ARCHITECTURAL AND ARTISTIC ASSETS

Heritage building stock represents a significant element at risk under earthquakes, as recent seismic events have shown, especially in the Mediterranean area. In fact, in the last few years, the issue of its seismic vulnerability assessment is widely discussed by the scientific community. The procedures for the vulnerability assessments involve many critical points, related to the complexity and uncertainty of the parameters involved. In the last few years, the scientific literature has proposed several multi-level procedures adequate for the regional scale analyses of existing buildings of different typology. In particular, among historical constructions, masonry churches have been studied in detail in Italy, proposing empiric approaches in which a vulnerability index is defined based on the classification of recurrent failure mechanisms, and exploiting a macro-elements approach in order to identify the parameters influencing the index. On the other hand, intangible aspects related to the architectural, historical and artistic value, both for the structural part themselves or for additional non-structural elements or contents, are not included in the Index. This paper proposes a procedure that integrates the well-known vulnerability evaluation of existing masonry churches with the evaluation of the exposure related to the artistic and architectural value of structural parts and additional artwork such as frescoes, statues and paintings. In particular, the new methodology will provide a new “Index of artistic and architectural asset” through the application of the Analytic Hierarchy Process. The final objective of the work is to provide a complete information about the seismic risk to regional scale, adapt for elaborating a prioritization scale for the assessment and retrofit of existing masonry churches.