Some time back I mentioned that I was being "taken to task" by a reviewer
for putting grout beneath my column baseplates for an overhead sign
structure. Well, mea culpa (I guess) because the guy was right in pointing
out that the Texas Department of Transportation standard drawings AND
specifications explicitly state "no grout under baseplates".
First, I'm not sure why they have a problem with it, but I'll let that
Studying their standard details (duh!) I note that they seem to expect all
the tension AND compression loading on the baseplate to be taken directly by
the anchor bolts themselves. These anchor bolts project either directly into
a drilled shaft foundation, or into a "camelback" piece of traffic railing
that is itself supported by drilled shaft foundations.
The anchor bolts are four in number, arranged in a rectangular pattern as
close (it appears as possible to the supported column). They consist of
threaded bar stock typically 1 1/2" in diameter and 3 ft to 4 ft in length.
They are "connnected" to one another at the bottom of the bolts with at
rectangular steel "template" of unspecified thickness, which itself has a
rectangular opening to allow passage of conduit for cables, etc.
It APPEARS that this template is acting as a mechanical anchor for the
anchor bolts, but I'm not sure how they modeled it. Your pardon if this
seems like it should be obvious, but I just don't see this. If this is such
a wondrous system, why arre we wasting all our time with grouted base
I'd like someone to give such insights as they have into how all this works.
Thanks for the discussion.