A Pushover-Based Preventive Procedure for Assessing the Seismic Performance of Masonry Structures Under Earthquake Sequences

The Mediterranean is a well-known seismic region where earthquakes often occur as repeated shocks of similar intensity. Most of the built heritage consists of masonry structures, which are inherently vulnerable to horizontal loads. To preserve these constructions and ensure public safety, it is essential to assess their behavior under repeated seismic events. This study proposes a preventive assessment procedure for existing structures based on pushover analyses of Finite Element models, combined with the N2-method, methods usually adopted in common practice and recognized by European and Italian building codes. First, the capacity curve (in terms of base shear force vs. displacement) of the undamaged structure is assessed through a pushover analysis, and the structural performance point is identified with the N2-method against the design earthquake prescribed by the standards. Once the performance point is identified, the structural damage induced by the design earthquake can be quantified. The capacity curve of the damaged structure is assessed performing a pushover analysis on the damaged model, determining its performance under a second design earthquake through the N2-method. The procedure is applied to a masonry arch with buttresses and is validated through non-linear dynamic analysis.