requirements for a weld washer at a beam connection that has

huangyhg

requirements for a weld washer at a beam connection that has
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!
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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.
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.
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.
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??
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.