Performance Assessment of Buckling‐Restrained Braced Frames Subjected to Near Field Earthquake

Abstract

Ground motions recorded within 10‐15 km of a seismic source display distinct near‐field characteristics, most notably high amplitude velocity pulses associated with forward directivity and fling‐step effects. These pulses release large amounts of seismic energy within a few cycles, imposing severe demands on structures. To mitigate such effects, passive control devices are effective, with buckling restrained braces (BRBs) offering stable hysteretic behaviour under both tension and compression, enabling significant energy dissipation. This study investigates the seismic performance of buckling restrained braced frames (BRBFs) with diagonal and inverted‐V configurations in 3, 6, 9 and 18‐story buildings subjected to recorded near‐field ground motions. Nonlinear analyses were conducted in OpenSees(OS) to evaluate interstory drift ratios, yielding mechanism, brace hysteresis behaviour, and energy dissipation demands. Results reveal that the impact of near‐field pulses is influenced by building height and bracing configuration, with inverted‐V layouts enhancing energy dissipation in mid to high‐rise frames. Findings provide useful insights for optimising buckling‐restrained braced frame design under near‐fault seismic hazards.