[TowerTalk] Advice needed on embedding guy anchor rod in concrete deadman

[jimlux]

On 6/10/16 8:08 PM, Richard (Rick) Karlquist wrote:
> I'm planning some concrete deadman guy anchors
> using Rohn GAC303 or Endurance Helix4-54 anchor
> rods, to be embedded in the concrete.  I am
> looking for suggestions on how to fixture
> the rod correctly to prepare for the concrete pour.
> Obviously, I need to get both the azimuth and
> elevations angles correct so that the guy cable
> pulls in a pure axial mode, without putting
> a deflecting load on the rod.  I'm trying to
> brainstorm some positioning technique.  Any
> suggestions?  How about if I pre-attach the
> rod to a rectangular piece of plywood at the correct
> elevation angle.  Then I mount the plywood
> such that it is square and plumb with respect
> to the foundation perimeter?
>
> Alternately, I tie the bottom of the rod into
> the rebar cage and install a temporary post
> in the ground that will support the top of the
> anchor rod.  Seems difficult to get this post
> correctly positioned in 3 dimensional space.
>

I would think of some sort of wooden cribbing - not a single post 
because it's easy to knock it, but maybe a couple of posts and wire them 
together?

Sure, you want it "reasonably close" to aligned, realistically, 10-15 
degrees is probably close enough.  The rod will bend a bit under the 
load, won't it?

When I worked at a place where they placed the anchors with a hydraulic 
system on a truck, they basically got "close" to the right orientation 
as they screwed them into the ground.  When we loaded the guys, either 
the shaft of the anchor bent or there was an angle between the guy and 
the shaft, depending on the load and the size of the shaft (it takes a 
fairly hefty load to bend a 1" solid bar of steel).





> Surely someone has solved this problem before.
> I don't remember seeing any previous discussion
> of it on TT.
>
> Rick N6RK
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