Alternative passive energy-based retrofit of an earthquake damaged reinforced concrete structure

An alternative passive energy-based retrofit design is proposed for a reinforced concrete building, seismically retrofitted in 2013 and damaged by the 2016 Central Italy earthquake. An evaluation analysis carried out by referring to the pre-2013 conditions shows unsafe stress states in most structural members and severe damage in the masonry partitions and perimeter infills. The alternative retrofit strategy of the building, which consists in the incorporation of a dissipative bracing system equipped with pressurized fluid viscous spring-dampers, allows attaining a substantial seismic performance improvement. This is assessed by a safe response of all columns and beams, and at most a very slight damage in the masonry panels, in post-intervention conditions.