Requirements for a weld washer at a beam connection that has been slot 3

[wesstallmann]

I have a condition where I need to slot some holes on a beam to anchor bolt connection (AB's were misplaced). I have heard rumors that there is a code that requires a weld washer be installed on the flange to better hold the beam in position. I am wanting to find out what the requirements for the size of the weld washer are, specifically the thickness. Someone told me ot was a min. 1/2 the thickness of the flange ( in my situation). I would like to nail down what the exact requirements are rather than trust rumor. If you know where I can find this information please let me know (specific code requirements)
Thanks Guys!

 

[Lion06]

There is actually a requirement to completely cover a long-slotted hole that is in an outer ply. See AISC 360-05 spec section J3.2(third paragraph on page 16.1-106. It says not less than 5/16" thick.

 

[Ron]

It is not a weld washer, but a plate washer, and as StructuralEIT noted, at least 5/16" thick. It should cover the slot because of the potential for "in slot" deformation during loading.

 

[nutte]

That requirement is for steel-to-steel bolted connections. It wouldn't apply to an anchor bolt connection.

Depending on the slot/hole size, plate washers might be necessary, but I'm not sure of a prescriptive requirement for their thickness.

 

[wesstallmann]

To clarify, AB's on top of masonry pilaster intended for beam to seat on top of the bolts. I think that the plates are intended to negate horizontal shifting if the holes remained slotted. Does that clarify anything??

 

[rcd445]

AISC Design Guide #10 (page 16) says: "...as a rule of thumb, it is suggested that the thickness of the washers be a minimum of 1/3 the diameter of the anchor rod, and the length and width of the washers equal the base base plate hole diameter plus one inch as a minimum." This is a guide for a round hole but the same logic would seem appropriate for an elongated hole. These plate washers do not need to be hardened ASTM F436 washers.