Transmission Tower Anchors

[dauwerda]

I am curious about people's experience using threaded rebar (14J and 18J) as anchors for transmission towers.
Do you specify the use of 14J and/or 18J threaded rebar for anchors? If so, have you had any push back from suppliers. My experience has been that these are getting harder and harder to source and can cost up to twice the amount of more typical F1554 heavy Hex Anchors (with the same diameter and length). Is anyone else having a similar experience, and if not where are you ordering your anchors from?
We recently had a vendor supply prices for both 14J anchors and 1-3/4" dia. F1554 Gr.55 Heavy Hex Anchors for a project with 27 anchor cages. The quote for 14J threaded rebar was $31,080.00. and the quote for 1 3/4" F1554 Gr 55 anchors was $18,700.00

 

[jwkilgore]

I asked several suppliers (Valmont, Sabre, etc.) at the ASCE ETS conference a few months ago in Atlanta. All were still regularly using 18J anchor rods for engineered poles and haven't seen a major shift to F1554. All of my utility clients still spec 18J rods, either full-length anchor-rods as the entirety of the reinforcing cage or else shorter anchor rods transferring to a standard cage.

Personally, as our standard detail has nuts with a spacer/template at the bottom of the 18J bars anyway, the deformations aren't really necessary. If the client allowed it I would go with F1554 without hesitation for poles. But so far none have been willing to make the switch, and they're the one paying for it. The old "that's the way we've always done it" argument.

But I specifically asked about 18J for poles, not 14J. It may be different in your situation with the smaller anchor rods. The only client I have that still regularly installs new lattice towers uses stub-angles, not anchor rods.

 

[transmissiontowers]

The 18J's typically call for a minimum Charpy value. We usually specify A706 that are weldable incase someone bends one over during installation of the pole. We usually don't thread the bottom but use U-Bolts and rolled rings to keep the bolts in alignment.

And yes, our industry boldly goes where we have always gone before.

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I have been called "A storehouse of worthless information" many times.

 

[dauwerda]

Hey transmissiontowers, any word on when we can expect to see the newest edition of ASCE 113? Or when it might be up for public comment?
Thanks!

 

[transmissiontowers]

We are meeting next week to talk about it. Hopefully we will make some progress, but don't hold your breath. We still have to get it where all committee members agree and then on to peer review and address comments.

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I have been called "A storehouse of worthless information" many times.