8.5 Interconnection of Elements
If the frame girders bear on column corbels, the length of bearing is greater than 3 inches.
The deficiency is in the length of bearing. Calculate the inter-story drift. Judge the adequacy of the connections to retain their vertical load-carrying integrity at a maximum drift estimated to be equal to the drift calculated with the unreduced demand. Conforming buildings that fail this check shall be placed in SPC 4.
The frame girders are not supported on corbels with welded elements.
The deficiency is in the strength of the connection. Check all welded connections that transfer lateral loads or are subject to frame action. Determine where connection failures would be brittle (e.g., pull-out of embedded item would occur before yield of mild steel element). Analyze structure for capacity without such connections or check such connections for seismic force amplified by factor Cd/2, but not less than 1.5. For connections that can allow the diaphragm to fail in a brittle manner, the R values used in computing the seismic demand shall be consistent with those for brittle systems (not to exceed R = 2). Conforming buildings that fail this check shall be placed in SPC 4.