Short Slots in Collectors 1

[SteelPE]

I am currently in the process of reviewing shop drawings for a very large warehouse type structure. The structure was designed in accordance with IBC 2015/AISC 14th edition. I located the LFRS (lateral force resisting system) around the perimeter of the building utilizing a concentric brace frame.

At the perimeter steel, the fabrication is calling for short slots in all of the beam to column connections. I would like to avoid this type of hole in these elements as these beams are acting as collectors for the brace frame system. Out of interest, I went digging into the AISC and they seem to allow for short slotted holes at the discretion of the EOR. The commentary has some discussion about why short slots are allows.... and shocker, it has to do with allowing for proper plumbing of the columns.

In this instance, where the perimeter beams are acting as a collector for the LFRS what are others doing? Are you allowing for short slots to be used in this instance? or do you insist on STD holes?

 

[RWW0002]

@271828 - I am not sure why gravity capacity of the connectors would come into play in this case. If the slip critical bolts are only being used in order to address the collector loading in the direction of the slots, why could you not use design values for bearing for gravity loads (perp. to slot direction) and slip-critical values for lateral loading only (in the direction of the slots)..

In the past I have left this up to the steel detailer - I tell them to use standard holes, however if slots are required for erection tolerance then slip-critical connections may be used at the steel contractor's option (as long as SC bolts are still adequate for the collector loads obviously).