Seismic performance of structures equipped with BRB

Over the years, the buckling restrained braces (BRBs) have more and more become one of the best solutions for retrofitting or upgrading many existing reinforced concrete framed buildings located in areas with a high seismic hazard. The present investigation studies the effectiveness of BRBs used to seismically retrofit a reinforced concrete (RC) building in L'Aquila defining an advanced non-linear 3D model in OpenSees. The seismic performance of the investigated building is assessed developing the following comparisons: before and after the retrofit through BRBs. Adopting a hysteretic model specific for the BRBs, both non-linear static analyses and incremental dynamic analyses under a set of real ground motion records are carried out to build the seismic demand hazard curves. The numerical results highlighted the influence of the BRBs on the seismic performance of the system components also in relation to the effectiveness of the retrofit.