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RE: Baseplate Anchorage

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Scott / Roger,

I understand and agree with your assessment of "stabbing" anchors into
concrete but this did bring up another concept that I haven't resolved for
myself. What do you think of pouring the concrete, "stabbing" the anchor but
before hitting the concrete with the "stinger"? Does the "delayed" vibration
bring you back to a condition similar to having the anchor held in place
before pouring concrete and if not, what am I missing or what has happened
that causes it to be different?

Just curious,
Calvin
Portland, OR


		-----Original Message-----
		From:	Scott Maxwell [mailto:smaxwell(--nospam--at)engin.umich.edu]
		Sent:	Tuesday, October 29, 2002 10:41 AM
		To:	seaint(--nospam--at)seaint.org
		Subject:	Re: Baseplate Anchorage

		David,

		I will second Roger's (and your) concern about "stabbing"
the anchors into
		the concrete.  Not particularly a good idea and something
that I typically
		don't permit.

		Having said that, if you are "forced" into that situation,
then you could
		look at headed studs or rebar with a hook on it to act as
anchors, as
		someone else pointed out.  The headed stud are actually
meant to be welded
		on in that fashion.  Rebars could attached in a number of
		fashions...welded directly to the plate at the bar end (weld
around the
		perimeter of hte bar diameter), welded directly to the plate
by first
		bending a horizontal leg and then welding that leg (although
would have to
		worry about a possible "zipper" effect on the welded
portion), could weld
		a threaded coupler (from someone like Erico) then thread the
bar to the
		coupler (again these types of couplers are designed to be
welded in this
		fashion), etc.

		HTH,

		Scott
		Ypsilanti, MI


		On Tue, 29 Oct 2002, M. David Finley, P.E. wrote:

		> Roger,
		>
		> Acutally they will be constructing a frame to hold the
"new" plates in
		> position.  I agree with your concerns about stabbing
anchors into plastic
		> concrete.  I also anticipate requiring c couple of holes
in the baseplate to
		> allow trapped air to escape and help ensure proper
concrete consolidation.
		>
		> I had envisioned endplates on the angles or channels - a
similar concept to
		> headed anchors.  If  I use anchor rods, I would probably
use ASTM F1554
		> grade 55.  How is the weldability supplement speicified?
ASTM F1554, Grade
		> 55 with weldability supplement?  or is there a slightly
more formal
		> phrasing?  Of course, my initial concern was just how good
a welded tension
		> connection could be made between the anchor rod and the
bottom of the new
		> baseplate.
		>
		> M. David Finley, P.E.
		> 2086 SW Main Boulevard - Suite 111
		> Lake City, FL  32025
		> 386-752-6400
		>
		> ----- Original Message -----
		> From: "Roger Turk" <73527.1356(--nospam--at)compuserve.com>
		> To: <seaint(--nospam--at)seaint.org>
		> Sent: Tuesday, October 29, 2002 9:50 AM
		> Subject: Baseplate Anchorage
		>
		>
		> > Dave,
		> >
		> > It sounds like they want to "punch" the anchors into
plastic concrete. My
		> > GSN specifically prohibits this as it always leaves a
void above whatever
		> > projection the anchor uses to engage the concrete.
		> >
		> > With 75 kips uplift, you have to engage 750 cu. ft. of
concrete to provide
		> > uplift resistance and I wouldn't want to take the chance
of a void being
		> > above or alongside any anchor.  Nor would I want to rely
on bond on
		> > vertically oriented angles for this amount of uplift.
		> >
		> > HTH
		> >
		> > A. Roger Turk, P.E.(Structural)
		> > Tucson, Arizona
		> >
		> > David Finley wrote:
		> >
		> > . > I've got a project where some industrial equipment
is being relocated.
		> > . > Rather than cut the baseplates loose, the owner
wants to cut off the
		> > . > existing anchor bolts and then move the equipment to
the new location.
		> The
		> > . > supporting legs, with baseplates still welded on,
will then be set
		> onto
		> > . > new (larger) baseplates and the 2 plates welded
together.
		> >
		> > . > For the new baseplate, they want to weld "j-hooks"
to the bottom of
		> the
		> > . > plate to eliminate any projection through the
baseplate. I'm somewhat
		> > . > concerned about whether they will actually use
weldable material (no
		> > . > matter what I spec) and how good a weld can really
be achieved this
		> way.
		> > . > Obivously there is no way to inspect the assembly
after the concrete
		> has
		> > . > been cast.
		> >
		> > . > In lieu of anchor bolts, I'm considering using
vertically oriented
		> angles
		> > . > or channels so that the weld length is substantially
longer.  Any
		> > . > thoughts or other suggestions?  Each leg is subject
to about 75 kips
		> of
		> > . > uplift (service load).
		> >
		> > . > M. David Finley, P.E.
		> >
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