Our faculty member, Assoc. Prof. Reşat Atalay Oyguç, contributed to a recent research collaboration resulting in the publication “Seismic Retrofitting of Substandard RC Frames Using Tube-in-Tube Buckling-Restrained Braces: Shake Table Evaluation and Field Insights,” published in Bulletin of Earthquake Engineering. The study investigates the use of an all-steel Tube-in-Tube Buckling-Restrained Brace (TnT-BRB) system to strengthen deficient reinforced concrete (RC) frames. The research combined large-scale cyclic tests of TnT-BRB components with shake table experiments on one-third scale single-story RC frames, comparing an unretrofitted specimen with one equipped with the TnT-BRB system.

The retrofitted frame demonstrated substantial improvements in lateral stiffness, deformation capacity, and energy dissipation under increasing earthquake intensities, while the unretrofitted frame suffered brittle joint failures, shear cracking, and residual drift. In tests replicating the 2023 Kahramanmaraş earthquake, the retrofitted frame preserved its structural integrity and exhibited controlled yielding as intended. These results highlight the system’s practical feasibility and its potential to transform vulnerable RC frames into ductile, earthquake-resilient structures.


          (a) Details of Specimen 1 (Bare Frame) and (b) Specimen 2 (TnT Frame)

To read the full article: https://doi.org/10.1007/s10518-025-02229-3