Performance-Based Seismic Design of Hybrid Isolation Systems with Gap-Tunable BRBs for Bearing-Supported Bridges

This study proposes a class of hybrid isolation systems constructed by combining Buckling Restrained Braces (BRBs) with Rubber Bearings (RBs) or Lead (LRBs) for mitigating the seismic responses in bearing-supported bridges under strong earthquakes. Firstly, two different (RB–BRB and LRB–BRB) were preliminarily designed based on energy-conservation concept case bridge Y-shaped piers, which can meet all energy demands at hazard levels. Further, evaluations conducted LRB, RB–BRB, LRB–BRB nonlinear time history analyses. The proposed show two-phase dissipation behavior, facilitates to reduce remarkably earthquake scenarios achieve most performance objectives corresponding code-specified Finally, fragility analyses, effects gap spacing stiffness ratio BRB pier investigated respect failure probability LRB–BRB. It has been validated that performances this study’s be improved considerably optimized stiffness.