# Pole light anchor bolts



## wcord (Jan 23, 2011)

pjg said:


> We went to replace a 400 watt MH fixture with a LED and found the nuts on the anchor bolts were loose and unable to be tightened due to thread damage and corrosion. I have planned to remove the pole and epoxy 1" threaded rod into 9" deep new holes and reset the pole. I consulted with Hilti on the proper materials and the tension strength of the bolts in 2500# psi concrete is 21,060 lbs and shear of 45,360 lbs.
> 
> Does any body have experience with this type of repair?
> 
> ...


Somehow 9"deep doesn't seem enough. Last time we did a bolt replacement, the engineers wanted a minimum of 24"


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## ponyboy (Nov 18, 2012)

wcord said:


> Somehow 9"deep doesn't seem enough. Last time we did a bolt replacement, the engineers wanted a minimum of 24"



Probably depends on the pole height and weight


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## wildleg (Apr 12, 2009)

it also depends on the wind loading (different areas require different wind load calculations.

you can't repair the threads ?


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## pjg (Nov 11, 2008)

wildleg said:


> it also depends on the wind loading (different areas require different wind load calculations.
> 
> you can't repair the threads ?


The threads are flattened due to pole movement and bent. There is significant pitting of the bolt from rust. I'm trying to find info on the wind loading and it's resulting tension on the bolts.


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## ampman (Apr 2, 2009)

How do you know the existing concrete is 2500 psi sounds like the whole form needs replacing 220/221 does a lot of these type of repairs he can help


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## ponyboy (Nov 18, 2012)

wildleg said:


> you can't repair the threads ?



Truth. Have a machinist look at it maybe. You'd be surprised what they can do. Maybe they're not salvageable like he's saying but it can't hurt to look. 


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## ampman (Apr 2, 2009)

ponyboy said:


> Truth. Have a machinist look at it maybe. You'd be surprised what they can do. Maybe they're not salvageable like he's saying but it can't hurt to look.
> 
> 
> Sent from my iPad using Tapatalk


You are going to pay a machinist to come out and look at threads hell why not have an engineer come out to


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## Cow (Jan 16, 2008)

I think I'd try using a die to chase the threads with and then double nutting it if I was concerned the original nuts wouldn't have enough holding power.

But, I have done the hole-epoxy-allthread method on one pole that had a damaged top. It was a small aluminum pole though, maybe 15' or so and it was in a hospital parking lot. I suppose that's a small comfort in case my repair doesn't hold...


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## garfield (Jul 30, 2009)

Once you have a proper drill etc it doesn't take long to drill 12 inches and epoxy that in. I second just getting a die to fix the threads if possible.


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## ponyboy (Nov 18, 2012)

ampman said:


> You are going to pay a machinist to come out and look at threads hell why not have an engineer come out to



Yeah I forgot not everybody here works with 20 of them every day. It's nice when you can break something expensive and have it fixed the same day


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## sbrn33 (Mar 15, 2007)

I third the idea of getting a die and re-threading the existing. I would trust the originals way before I would trust must threaded rod epoxied in. Short pole might be different.


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## chewy (May 9, 2010)

sbrn33 said:


> I third the idea of getting a die and re-threading the existing. I would trust the originals way before I would trust must threaded rod epoxied in. Short pole might be different.


Chemical anchors are good as gold, no fear of cracking the concrete if the hole you drilled is close to the edge or little bit too big.


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## LGLS (Nov 10, 2007)

Sometimes what you think is an anchor bolt is really just a stud, threaded into a rod coupling and then to the anchor bolt inside the foundation. This is done in case the pole is hit by a car, the entire foundation isn't trashed. The damaged studs just unscrew and new ones installed.


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## blueheels2 (Apr 22, 2009)

Did 30 of these back in November. 30' poles double head and we had to drill 2' deep. We were using 1".


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