AbstractNonlinear response history analyses were conducted to determine the seismic collapse safety and seismic performance of buildings with special steel moment frames using Simpson Strong-Tie Strong-Frame moment frames compared to equivalent buildings using reduced beam section (RBS) moment frames. The Strong-Frame moment connection consists of a modified T-stub or end plate connection incorporating Yield-Link structural fuses for moment transfer, and a modified shear plate connection for shear transfer. Archetypical 4-story, 8-story, 12-story, and 20-story steel frame buildings designed using ASCE 7-16 were evaluated. The results indicate that the Strong-Frame buildings have a 36% larger adjusted collapse margin ratio and are less likely to collapse, compared to the RBS buildings. The Strong-Frame buildings also have lower probable repair costs and shorter repair time compared to the RBS buildings. The improved collapse safety and enhanced performance of the Strong-Frame buildings are attributed to the stronger column web panel zone, inclusion of column bending moments in seismic overstrength load combinations, delayed connection strength degradation, a distributed global collapse mechanism, and replaceable connection components.
