Fragility curves for Italian residential masonry buildings with retrofit interventions

The earthquakes of the last decades have shown that the Italian residential masonry built her-itage has high seismic vulnerability, in particular when considering structures built before 1919. For this reason, it is necessary to develop effective large-scale risk mitigation strategies in order to reduce the huge losses that could occur in the aftermath of an earthquake. In this paper some retrofit interventions applicable mainly to old buildings are presented, explaining their advantages and potential. These interventions are then implemented, through Vulnus 4.0 software, on a database of 205 buildings built before 1919, previously analyzed in their as-built state. Fragility curves are then developed for each building, and are processed in order to create a vulnerability model for different construction periods that takes into account the possible ret-rofit intervention strategies. Therefore, this procedure allows a comparison between pre and post retrofit intervention fragility, and the results in terms of curves can be used for large scale damage and risk simulations.