Performance-based approach to earthquake protection of masonry cultural heritage

Within the framework of Performance Based Assessment (PBA), the paper focuses on the implementation to the case of ancient masonry constructions. Actually, the complexity and wide variety of historical masonry buildings (such as churches, palaces, towers, columns, etc.) require the adoption of different modelling strategies, through a versatile procedure. Within this context, one of the main issues is the definition of performance levels on the capacity curve, provided by the nonlinear pushover analysis. Firstly, performance objectives have to be defined also considering cultural relevance concepts: thus, the preservation of the cultural heritage asset and the safety of the people using it should be considered in an integrated approach. To this aim, in the paper, a multicriteria approach to define damage levels is proposed by considering: a) the damage at the scale of structural element (local damage), b) the mechanisms in architectonic elements (macroelement), c) the global behaviour of the building (represented by its pushover curve). Then, proper criteria are established to correlate damage at the three scales and define performance levels on the capacity curve.