Rapid seismic retrofit of damaged RC frames using gapped eccentric steel brace system equipped with dampers

Abstract

Earthquake-damaged buildings need to be quickly restored to mitigate secondary disasters and social impacts. A rapid seismic retrofitting method using gapped eccentric steel brace (GESB) system for rehabilitation of damaged RC frames was proposed in this study. A single-story single-bay RC frame was subjected to quasi-static cyclic loading until reached collapse limit state. The GESB system with parabolic metallic damper was installed in the damaged frame to quickly rehabilitate its seismic performance. No repair or local strengthening was conducted during the construction. The retrofitted frame was subjected to the same loading procedure with the reference one. Test results showed that the GESB system restored the seismic performance of the frame with little influence on the fundamental period of the structure. The retrofitted frame exhibited superior energy dissipation and peak strength. A case study based on the nonlinear dynamic analysis of the finite element model was carried out. It was concluded that the employed GESB was effective in retrofitting the damaged RC frame.