RCSC Section 6 tells you everything you need to know about washers. There's no impact on capacity, but they are definitely required under the head in certain circumstances.
https://www.aisc.org/publications/steel-standards/rcsc/
Yeah, case 3 is not appropriate here. By following case 3 you have Hb equal to zero, Hc equal to 72.6k, and are dumping significant moment into the column. This does not match the assumptions in example 5.12.
I'd try starting over with the general UFM case, with the workpoint set at the...
Can you post a picture of your mathcad analysis?
I do not believe special case 3 applies to the gusset-to-base plate case, which has connections to both the horizontal and vertical interface. I think you'd need to use the general UFM case where "e" would be the beam eccentricity "eb" but with a...
The intent is that the top chord has local bending capacity as if you treated it like a beam spanning from panel point to panel point, to carry the 100# load. Anything in excess should have a field installed diagonal web member bringing the load back to a panel point (i.e. carried only by axial...
Draw a shear/moment diagram for the uniform load the joist is capable of supporting. As long as the induced shear/bending from the 100# loads does not create a larger bending moment or shear load than the envelope, it would be acceptable.
OSHA laying the blame on the contractor:
Link
I'll save my thoughts on PEMBs, but they are extremely scary while they're going up. Hopefully OSHA publishes the results of its investigation soon.
