SMA-based rocking dual-core braced-frame system for seismic retrofit of RC buildings

New seismic-resistant systems enhance structural resilience by dissipating energy, minimizing damage, and enabling self-centering for efficient post-earthquake recovery. Among them, base-rocking dual-core (BRDC) braced-frame systems have shown promise for retrofitting existing buildings. This study investigates the application of a BRDC exoskeleton equipped with shape memory alloy (SMA) dampers for the seismic retrofit of reinforced concrete (RC) buildings. The SMA dampers function as replaceable fuses, providing energy dissipation while facilitating the self-centering of the structure to its original position. A displacement-based design method is proposed to optimize the performance of the SMA dampers. Nonlinear analyses demonstrate that the proposed system effectively reduces inter-story drifts and enhances seismic resilience. The results underscore the promise of this retrofit strategy. By ensuring both structural integrity and rapid post-earthquake recovery, the approach offers a viable solution for the protection of critical infrastructure.