SEISMIC RELIABILITY-BASED DESIGN OF STRUCTURES EQUIPPED WITH DFPS

This work deals with seismic reliability-based design (SRBD) for softening and hardening structures equipped with double friction pendulum system (DFPS) isolators. The isolated system is represented by means of an equivalent 3dof model having a softening/hardening post-yield slope for the superstructure and velocity-dependent rules for the two surfaces of the DFP devices. The yielding characteristics of the superstructures are defined in compli-ance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming ordinary characteristics. Considering several natural seismic records and the relevant random varia-bles, incremental dynamic analyses are carried out for assessing the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability-based design (SRBD) curves for these systems are proposed.