Abstract: Presented herein is an assessment of current nonlinear
static procedures (NSPs) for seismic evaluation of bucklingrestrained
braced frames (BRBFs) which have become a favorable
lateral-force resisting system for earthquake resistant buildings. The
bias and accuracy of modal, improved modal pushover analysis
(MPA, IMPA) and mass proportional pushover (MPP) procedures
are comparatively investigated when they are applied to BRBF
buildings subjected to two sets of strong ground motions. The
assessment is based on a comparison of seismic displacement
demands such as target roof displacements, peak floor/roof
displacements and inter-story drifts. The NSP estimates are compared
to 'exact' results from nonlinear response history analysis (NLRHA).
The response statistics presented show that the MPP
procedure tends to significantly overestimate seismic demands of
lower stories of tall buildings considered in this study while MPA
and IMPA procedures provide reasonably accurate results in
estimating maximum inter-story drift over all stories of studied BRBF
systems.