Novel Capacity‐Adjustable BRB for Improving the Seismic Performance of Tall‐Pier Bridges

Tall‐pier bridges are commonly employed in mountainous or deep‐water regions. Ensuring the postearthquake serviceability is crucial for the seismic design of tall‐pier bridges. Buckling‐restrained braces (BRBs), serving as prevalent replaceable energy‐dissipating components, can effectively enhance the seismic performance of such bridges. For the seismic design of tall‐pier bridges, the objective is typically to minimize their structural responses under small to moderate earthquakes to maintain serviceability. Under rare or extremely rare earthquakes, efforts should be made to reduce seismic damage to the piers, thereby ensuring their postearthquake repairability. This study proposes a novel capacity‐adjustable BRB (CABRB) to improve the seismic performance of double‐column tall‐pier bridges. The mechanical behavior of the CABRB is initially investigated through experimental studies and numerical simulations. Building upon these, a representative tall‐pier bridge is selected as the research object. Comparative analyses of its seismic performance are conducted under three distinct pier configurations: prototype pier, BRB pier, and CABRB pier. The results indicate that the installation of CABRBs effectively reduces the displacement response at the pier top and the curvature response at the pier base, significantly enhancing the seismic performance of tall‐pier bridges.