Recent advancements in seismic retrofit strategies have focused on low-impact, rapid, and reversible interventions, with self-centering rocking dual-frame (SCR-DF) systems demonstrating strong potential for enhancing the seismic resilience of reinforced concrete (RC) buildings. These systems, typically integrated as exoskeletons, improve seismic resistance by combining dissipative devices with post-tensioning and column uplift mechanisms to provide self-centering capability, thereby limiting residual deformations and facilitating rapid post-earthquake recovery. This research examines the development and effectiveness of a SCR-DF system applied as an external dissipative exoskeleton to enhance the seismic resilience of a real case study RC building. The expected seismic behavior of the SCR-DF system is validated through simulation results. Equations predicting the load-deformation behavior of the rocking systems are developed, ensuring accurate control of key limit states for reliable performance. Design parameters—such as frame configurations, overturning moment resistance, fuse properties, and post-tensioning stress—are optimized based on the inelastic behavior of the existing structure using a displacement-based design procedure. Nonlinear computational analyses are used to validate these designs. The peak interstory drift ratios (IDR) of the retrofitted building are significantly reduced compared to those of the existing structure, reaching approximately 0.69% in the X-direction and 1.07% in the Y-Direction. Residual interstory drift ratios (RIDRs) are effectively mitigated by the self-centering action of the post-tensioned rocking frames, with maximum values reduced to approximately 0.013% in the X-direction and 0.005% in the Y-direction, well below commonly accepted reparability thresholds of 0.1%. The results demonstrate that SCR-DF systems effectively manage interstory drift and residual displacements, maintaining minimal deformation even under maximum-considered earthquakes and facilitating post-earthquake repairs.
Seismic-resilient retrofit of RC buildings with self‐centering rocking dual-frame systems
Ferraioli M.
;Pecorari O.;
2026
Abstract
Recent advancements in seismic retrofit strategies have focused on low-impact, rapid, and reversible interventions, with self-centering rocking dual-frame (SCR-DF) systems demonstrating strong potential for enhancing the seismic resilience of reinforced concrete (RC) buildings. These systems, typically integrated as exoskeletons, improve seismic resistance by combining dissipative devices with post-tensioning and column uplift mechanisms to provide self-centering capability, thereby limiting residual deformations and facilitating rapid post-earthquake recovery. This research examines the development and effectiveness of a SCR-DF system applied as an external dissipative exoskeleton to enhance the seismic resilience of a real case study RC building. The expected seismic behavior of the SCR-DF system is validated through simulation results. Equations predicting the load-deformation behavior of the rocking systems are developed, ensuring accurate control of key limit states for reliable performance. Design parameters—such as frame configurations, overturning moment resistance, fuse properties, and post-tensioning stress—are optimized based on the inelastic behavior of the existing structure using a displacement-based design procedure. Nonlinear computational analyses are used to validate these designs. The peak interstory drift ratios (IDR) of the retrofitted building are significantly reduced compared to those of the existing structure, reaching approximately 0.69% in the X-direction and 1.07% in the Y-Direction. Residual interstory drift ratios (RIDRs) are effectively mitigated by the self-centering action of the post-tensioned rocking frames, with maximum values reduced to approximately 0.013% in the X-direction and 0.005% in the Y-direction, well below commonly accepted reparability thresholds of 0.1%. The results demonstrate that SCR-DF systems effectively manage interstory drift and residual displacements, maintaining minimal deformation even under maximum-considered earthquakes and facilitating post-earthquake repairs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
