PROBABILISTIC PERFORMANCE ASSESSMENT OF LOW- DUCTILITY RC FRAMES RETROFITTED WITH DISSIPATIVE BRACES

The paper illustrates a probabilistic methodology for assessing the vulnerability of existing reinforced concrete (RC) buildings with limited ductility capacity retrofitted by dissipative braces. The aim is to highlight the most important parameters controlling the capacity of these coupled systems and specific aspects concerning the response uncertainties. The proposed methodology is based on the development of fragility curves by performing incremental dynamic analysis within OpenSees and on the use of local engineering demand parameters. The capabilities of the methodology are tested by considering a benchmark RC frame designed for gravity-loads only and retrofitted by introducing elasto-plastic dissipative braces. The results show the effectiveness of the methodology and of the employed simulation software in describing the change of failure modalities due to retrofit.