Pre-code RC bare frame: Seismic retrofit with alternative strategies

In the last fifty years, a significant number of earthquakes that caused great economic losses and casualties have been recorded. In particular, in the last ten years, many seismic events occurred, and their medium magnitude caused great damage to the existing reinforced concrete buildings. In this context, the optimization of retrofitting strategies has become a crucial issue to evaluate the improvement of the probable seismic performance of the buildings in term of seismic risk reduction and repair costs. This paper deals with the seismic vulnerability of an existing reinforced concrete building not designed with the capacity design criterion. Different retrofitting strategies have been considered in order to evaluate more effective solutions in terms of seismic risk mitigation. The non-linear pushover analysis has been performed to evaluate the performance improvement of the building and compare the seismic behavior of the un-retrofitted and retrofitted building. Moreover, the seismic risk classes, pre and post-structural interventions, have been evaluated following the simplified methodology introduced with the Italian Ministerial Decree No 58/2017 about "Guidelines for seismic risk buildings classification".