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RE: More On Ungrouted Baseplates for Traffic Signal/SignageStruc ture s

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Thanks for the input.  Like Bill, I wouldn't have thought to go to PCI for
this type of information (since we're primarily discussing the design of the
steel baseplate & achor bolts). There does seem to be a little bit of a
"gap" in the application of the PCI guidance and Bill's situation.  You'll
note that the figure shows a 2" min grout space and that section clearly
states that the "ungrouted" condition is for erection loads and temporary
construction loads (emphasizing "temporary").  It also clearly states that:

"Under loads which occur at service, the base plate thickness may be
controlled by bearing on the conrete or grout.  In this case, the base plate
thickness is determined by ...."

Which implies to me that the author's intent is not to have an "ungrouted"
baseplate under service load conditions.  When you start talking signs &
cantiliver support structures I would expect the service loads to be much
greater than the temporary/construction loads; this is much different than a
precast column going into a normal building structure.  Even at that, it
would appear that PCI still wants grout under the column.  Have any thoughts
on my observations ?

Robert C. Rogers, PE

-----Original Message-----
From: Roger Davis [mailto:rdavis(--nospam--at)]
Sent: Wednesday, May 17, 2000 8:29 AM
To: seaint(--nospam--at)
Subject: RE: More On Ungrouted Baseplates for Traffic
Signal/SignageStruc ture s

The PCI Design Handbook for precast and prestressed concrete has a procedure
for designing this type of baseplate and anchorage.  It is in Section 6.10
of the Third Edition.  Their procedure is actually for erection and
temporary loads prior to grouting, but in precast concrete work those loads
can be pretty significant.  They do use bond between the anchors and
concrete in addition to bearing on the hook or bolt head, but you wouldn't
have to.  Anyway, they have a simple formula for sizing the base plate to
bear on the bolts instead of the grout.

Roger Davis
SDS Architects, Inc
205 N. Dewey Street
Eau Claire, WI 54703