A Comprehensive Set of Testing Protocols for Buckling-restrained Braces Applied to Bridges

Buckling-restrained braces (BRBs) have recently become popular as a ductile seismic force-resisting (energy dissipation) element in building structures (Uang et al., 2004). The upcoming edition of the California Department of Transportation's (Caltrans) Guide Specifications for Seismic Design of Steel Bridges is expected to contain the first set of guidelines for the use of BRBs on bridges (Lanning et al., 2014), however only the worst-case seismic demands have been thoroughly investigated (Lanning et al., 2013), resulting in very promising BRB performances. Currently, buckling-restrained braces (BRBs) within building frames must be prequalified through testing, as governed by American Institute of Steel Construction (AISC) 341, the AISC Seismic Provisions for Steel Structures. Similarly, in the proposed Caltrans guidelines (Lanning et al., 2014), the Near Fault Protocol is suggested for BRBs on long-span bridges near seismic faults. This protocol is likely not appropriate for long-span bridges far from faults nor conventional bridges at risk to either near- or far-fault ground motions