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RE: Short anchor bolt projection

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William Sherman wrote:

<<The anchor bolts were set correctly, but a connection redesign and field
modification at the top of the column requires us to make up 3/4"
somewhere - so we want to add 3/4" grout below the base plate.>>


Sorry I'm late in this response.

I think you may have more problems in trying to load your anchor bolts in
shear through a 2 1/4" +/- grout pad than you will with the partially
engaged bolts. If the shear loads are significant and there isn't much edge
distance in the grout, you could blow out the grout and then fail the anchor
bolts in bending. If that happens you might not have more than a couple of
kips capacity in shear per bolt.

Are you confident that all the loose crap and debris was blown out from
below the base plate before it was grouted? Or what about the "It's Miller
Time!" classic where the base plate is dry packed with a thin veneer of
putty around the perimeter? :)

Some personal experiences have made me very distrustful of grouted anchor
bolts taking serious shear loads. I usually use a more positive shear
connection such as a shear key or welding directly to an embed with headed

Just my tuppence worth.

John MacLean