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RE: Anchors in Bending Revisited

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Agreed again.  

For base plate to concrete anchorages with a significant shear and tension
load, I use an oversized setting template.  The setting template has shear
lugs and is cast into the concrete with the (headed) anchor bolts.  The
column and base plate are set on a shim stack and grout bed as usual.  The
anchor bolts have a plate washer to account for the oversize hole in the
base plate.  A plate is then welded to the setting the template and base
plate.  This transfers the shear without any slip from the base plate to the
setting template and shear lugs.  The tension is transferred to the anchor
bolts.  I have been using this detail for commercial buildings, power
plants, and other structures for about 20 years.

The original question and response are still valid.  The capacity is just
very low for normal building columns, base plates, and anchor bolts.  

Harold Sprague

> -----Original Message-----
> From:	Vyacheslav Gordin [SMTP:scgordin(--nospam--at)]
> Sent:	Tuesday, March 28, 2000 3:37 PM
> To:	seaint(--nospam--at)
> Subject:	Anchors in Bending Revisited
> Satish pinpointed the exact substance of the problem:
> Practically any eccentricity of the shear force in regard to the top of 
> concrete results in severe overstressing of concrete in simple bearing.
> It can be shown that such overstressed zone extends several inches below
> the 
> top of concrete, naturally leading to the overstress of the anchor in 
> bending.
> Such situation rarely develops under the DL and LL, but is quite common
> due 
> to WL and seismic.
> So, what do we do?