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#68504 - 08/09/06 10:38 AM Depth to bury a pole
Bill39 Offline
Member
Registered: 11/28/01
Posts: 75
Loc: Indianapolis, IN, USA
Is there a rule of thumb on how deep a power pole must be buried?

Is the burial depth more dependant on the height of the pole or the weight at the top of it(example:transformer, capacitors, etc.)?
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#68505 - 08/09/06 11:49 AM Re: Depth to bury a pole
energy7 Offline
Member
Registered: 06/10/02
Posts: 58
Loc: Oxnard, CA, USA
Weight downward on a pole is not a problem. Figuring worst case of about 600 lb./sq.in (NTS-1991) for wood, bearing on 1000 lb./sq.ft. soil (UBC, IBC); weight, even with XF's, cap's, etc. is well supported.
Resistance to overturning (lateral resistance) is a big deal. Wind load, seismic motion, and conductor tension are the factors, and must be calculated based on location (wind & seismic), soil type, and other factors that our engineers just snowed me with when I asked.
POCO's have standards that are well overdesigned for their areas and equipment, and are the closest to "rules-of-thumb" around.
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#68506 - 08/09/06 11:56 AM Re: Depth to bury a pole
iwire Offline
Moderator
Registered: 01/05/03
Posts: 4391
Loc: North Attleboro, MA USA
You can also find that type of info out in the Linemans and Cablemans Handbook.

Some libraries have it or you can buy it.

Lineman's and Cableman's Handbook



[This message has been edited by iwire (edited 08-09-2006).]
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#68507 - 08/09/06 02:30 PM Re: Depth to bury a pole
carjam Offline
Member
Registered: 05/06/05
Posts: 12
Loc: GrandBlanc, MI U.S.A.
I just set a 12 foot pole in a resi yard. The electrical inspector told me that ...i believe building code (not for sure now) for every 4 ft of pole you go 1ft deep. So i went 3 ft. deep seemed pretty sturdy to me.
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#68508 - 08/09/06 03:01 PM Re: Depth to bury a pole
122ss Offline
Junior Member
Registered: 04/29/04
Posts: 4
Loc: Purdum, Nebraska, USA
I asked the power co. that provides service in my area and they told me 10 percent of pole length plus 2 feet.
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#68509 - 08/09/06 11:47 PM Re: Depth to bury a pole
e57 Offline
Member
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
I have only set a few and it was a long (15 years) time ago. 6' for a 40' pole on straight runs, turns/angles deeper.

Taller poles are deeper ~8-10'.

I think the American Electricians Handbook also has some info in it.
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"Well - I oughta....." -Jackie Gleason
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#68510 - 08/10/06 02:06 AM Re: Depth to bury a pole
Trumpy Offline


Member
Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
As Energy7 mentioned above,
There are a few variables involved in the seating of a pole.
There is no way that there can be a formulaic way of calculating the depth for all situations.
Depending upon where you are in the world and the soil type and so forth,
It's a mine-field, it also depends upon what you are going to use the pole for.
We have used the formula 10%+ 2ft, with standard poles and have had them fall over when the ground freezes and then thaws, causing frost-heave.
My opinion would be, ask your local PoCo Lines Division.
And don't, set the pole in concrete, you are just looking for disaster, if you get bad frost levels and the pole is under any sort of strain.
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#68511 - 08/10/06 06:10 AM Re: Depth to bury a pole
electure Offline


Member
Registered: 12/24/00
Posts: 4259
Loc: Fullerton, CA USA
Quote:
As Energy7 mentioned above,
There are a few variables involved in the seating of a pole.


Yup, you need to take the conditions into consideration.

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#68512 - 08/10/06 12:00 PM Re: Depth to bury a pole
Nick Offline
Member
Registered: 08/13/01
Posts: 599
Loc: Riverside, CA
Electure,
Let me guess. Huntington Beach a little north of the pier south of the dog beach?
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#68513 - 08/10/06 06:16 PM Re: Depth to bury a pole
e57 Offline
Member
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
There are some in the Stinson/Bolinas lagoon... Hwy #1 in Marin.
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"Well - I oughta....." -Jackie Gleason
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