Seismic performance quantification of buckling-restrained braced RC frame structures under near-fault ground motions

摘要

The near-fault ground motion records with forward directivity (FS) and fling-step (FS) effects are characterized by the obvious velocity-pulses which will impose high seismic energy input to the building structures. The buckling-restrained braces (BRB) are one of the most commonly adopted lateral-force resisting and energy-dissipating components and BRBs are increasing configured in reinforced concrete (RC) frame structures to form a dual structural system (BRB-RCF). This paper presents the seismic performance quantification of BRB-RCFs subjected to near-fault ground motions with FD and FS effects. Suits of BRB-RCFs corresponding to different story numbers, BRB-resisted story shear ratios and BRB configuration types (single diagonal, inverted-V and V-type), were designed using the performance-based plastic design method. Three sets of 36 near-fault ground motions with FS, FD and non-pulse effects were selected. The seismic response including the maximum interstory drift ratio, floor acceleration, BRB ductility, BRB-resisted actual story shear ratio, etc., were investigated. Furthermore, the actual BRB-resisted story shear ratio was quantified and the design BRB-resisted story shear ratio was suggested. The analytical results can provide significant insights to the behavior quantification of BRB-RCFs when subjected to near-fault ground motions.