Seismic assessment and retrofitting of an under-designed RC frame through a displacement-based approach

Many existing reinforced concrete buildings were designed in Southern European countries before the introduction of modern seismic codes and thus they are potentially vulnerable to earthquakes. Consequently, simplified methodologies for the seismic assessment and retrofitting of existing structures are required. In this study, a displacement based procedure using non-linear static analyses is applied to a four-storey RC frame in order to obtain an initial estimation of the overall inadequacy of the original structure as well as the extent of different retrofitting interventions. Accurate numerical models are developed to reproduce the seismic response of the RC frame in the original configuration. The effectiveness of three different retrofitting solutions countering structural deficiencies of the RC frame is examined through the displacement based approach. Non-linear dynamic analyses are performed to assess and compare the seismic response of the frame in the original and retrofitted configurations.