Cyclic Behavior of Large Beam-column Assemblies

A series of experiments were conducted to verify the design criteria for beam-column joints under extreme seismic conditions for a 47-story building in San Francisco. The halfscale cruciform specimens were exceptionally large, requiring 18 in. deep sections. The overall size of the specimens was the largest ever tested in the U.S. for this kind of application. The data on the behavior of such large moment-resisting joints under severe cyclic loading are very limited. The experimental evidence clearly supports the use of stiffeners and doubler plates at the joints for the cross-sectional geometries tested. The results are of direct relevance to seismic design of many steel buildings.