Seismic upgrade of isolated bridges with supplemental vibration control devices

This study introduces a novel seismic protection strategy for isolated bridges by employing the internal mechanism of the Extended KDamper (EKD) as a supplemental vibration control device. The EKD is integrated within a two-span continuous bridge deck, positioned parallel to the isolators at the abutments and piers. To evaluate the effectiveness of this seismic protection strategy, a detailed mathematical model of the bridge system is developed, incorporating various mass-related vibration control devices (VCD), including the Tuned Mass Damper (TMD), the Tuned Mass Damper Inerter (TMDI) and the EKD. A series of parametric analyses is initially conducted to explore the influence of key design parameters of the examined VCDs on the dynamic response of the bridge. Subsequently, having defined the optimum range of the design variables, a constrained single-objective optimization framework is formulated, considering engineering performance criteria and manufacturing constraints to determine the optimal VCD configurations. The seismic performance of the optimized devices is evaluated using a comprehensive ground motion dataset, which includes real near-fault and far-fault earthquake records, as well as artificial accelerograms compatible with the EC8 seismic spectrum. The numerical results demonstrate that the EKD not only provides superior seismic mitigation compared to conventional mass-related VCDs, but also requires substantially lower additional mass (up to 25 times less). The findings of this study highlight the EKD’s potential as a highly efficient, lightweight, and practical seismic protection solution for isolated bridge structures, effectively addressing the key limitations of existing inertia-based systems, while significantly enhancing the overall resilience of bridges subjected to earthquake excitations. • Seismic upgrade of isolated bridges with supplemental KDamper devices (EKD). • The added mass of the EKD is up to 25 times lower compared to TMD systems. • Engineering criteria-driven optimization of EKD based on parametric analyses. • Performance assessment with real earthquakes and artificial accelerograms. • Robust lightweight seismic retrofit solution for isolated bridges.