Allowable gap in between faying surfaces of snug-tightened joints

[AraEng]

We have an HSS beam with end-plate connections (no moments at the ends) that's field modified. As a result the modification, the beam is short and the faying surfaces of one of end-plate connections have 7/16" gap in between them. The contractor has not used any shims. Instead, they've tightened the bolts enough to deform the end-plates (with 7/16" gap still visible in the middle of plates). I'm concerned about the secondary tension stresses in the A325 bolts. I can refer to the tolerance requirement on the length of the member in my documentation of the issue, but is there any requirement that limits maximum gap in between faying surfaces in a snug-tightened connection? I'm trying to avoid stress analysis of the bolts.

 

[canwesteng]

I'd be worried about prying more than anything here as you've deformed the plate. Is there any tension in the tension in the design connection?

 

[rb1957]

I don't see prying here, I see a heavily deformed web and highly loaded fasteners !

Why wouldn't the contractor use shims (not allowed on the drwg), or asked how to fix, or maybe packed the joint with washers (as shims) ? anything would be better than deforming the web by something like it's thickness ??

my 2c ... cut off the web, refinish the beam ends, maybe use shims to fill the gap, maybe add end plates to the beam ?

another day in paradise, or is paradise one day closer ?

 

[SwinnyGG]

The ASIC document that explains 'snug tight' actually says:

The plies should be in firm contact, a
condition that means the plies are solidly seated against each other,
but not necessarily in continuous contact.

Although I do not think this statement is intended to allow this type of situation.

I would also echo canwesteng's thought about prying in the fasteners- any tension on the beam is going to create very large prying forces, on top of the prying forces that are already there because of the fasteners deforming the flange.

Any compression in that beam is also going to result in at least 7/16" of displacement at one end or the other until the full strength/stiffness of the beam is available to resist the load.

The easiest solution would be to just cut a spacer the size of the flange, with the bolt hole pattern drilled into it, and install it at one end.

Whether or not that is acceptable is up to you, really... you say no moments at each end, so does that mean no shear force through this joint? Adding shims/spacers might compromise the joint's shear force capability, if that's a concern.

 

[dhengr]

AraEng:
Have them remove the HSS beam and properly straighten or replace the end plate. Then have the end pl. welds inspected for any cracking. Make two shim plates, the same size as the beam end pls., with the proper matching bolt holes, one pl. is 1/4" thk. and the other is 3/16" thk., and reinstall the HSS beam.

 

[atrizzy]

Can't improve upon what dhengr suggests.
It's hokey sh** like this that gets us in trouble.
I'm currently dealing with a steel installer who has pulled some egregious shenanigans that they didn't tell me about and I had to find out via inspections. It's very disheartening but, sadly, not surprising.