Incremental Dynamic Analysis of Mid-Rise Buildings with Buckling Restrained Brace Frame System under Pulse-Like Near-Fault Ground Motions

Abstract

Buckling Restrained Braced Frames (BRBFs) are frequently utilized as seismic force-resisting systems due to their considerable ductility and energy dissipation capacity. While BRBFs have shown reliable seismic performance in extensive experimental and numerical studies under far-field ground motions, research on their performance under near-fault ground motions is limited. near-fault ground motions, characterized by short-duration pulses with high amplitudes, impose greater seismic demands on structures. This study conducts Incremental Dynamic Analysis (IDA) on two 8- and 12-story BRBF structures under far-fault and near-fault ground motions. Comparison involves confidence intervals of average IDA curves rather than direct curve comparisons due to record selection uncertainty. At 99% confidence, no significant differences are observed. At 95% confidence, a minor difference is noted, while at 90%, substantial differences emerge, with confidence intervals indicating about a 25% difference for the 8-story and 75% for the 12-story structure. Residual drift comparisons show no significant difference at 99% confidence, a slight difference for the 12-story structure at 95%, and significant differences for both structures at 90% confidence. This suggests the importance of considering near-fault ground motions in assessing BRBF seismic performance, particularly for taller structures.