State-Dependent Seismic Fragility Functions for Italian Reinforced Concrete Structures: Preliminary Results

The present paper deals with the analytical assessment of structural vulnerability models for Italian reinforced concrete buildings that constitutes one of the results of the ongoing research project RISE (Real-time earthquake risk reduction for a ReSilient Europe). The structures under consideration are taken from the outcomes of the SERA project (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe) and refer to existing reinforced concrete residential Italian buildings. State-dependent fragility curves are evaluated via back-to-back incremental dynamic analyses using equivalent-single-degree-of- freedom systems. The analyses consider four damage states, identified by transient maximum inelastic displacement thresholds defined on the system’s backbone curve, and are performed with the DYANAS software. Such fragilities are required to calculate the seismic structural reliability when it is possible for structural failure to be reached progressively, i.e., due to the cumulative effect of multiple earthquakes.