Not wanting to continue to re-state the obvious - my initial response
stated there was a difference between our installations - would be nice
if you would acknowledge that, rather than continue to pursue the
"difference". As a former chief of engineering plans and programs for
the USAF, I have a basic understanding of failure analysis - but that
assumes there is a failure. Then again, I understand the
"tongue-in-cheek" response you're making.
73,
Joe
WDØM
David Gilbert wrote:
> You have bedrock to help keep your base from settling, and your base is
> pinned to the bedrock to keep the lateral forces on the tower from
> tilting the base. He has a layer of gravel over a water table deal
> with settling, and he has only the weight of the base to withstand the
> wind forces on a 90 foot freestanding tower. The AN Wireless towers (I
> have one) are spec'd for the foundation to be surrounded by undisturbed
> soil ... not air.
>
> My point is that the time to figure out whether something will survive
> is before you do it, not afterward. Engineering after the fact is
> called failure analysis.
>
> 73,
> Dave AB7E
>
>
>
> Joe - WDØM wrote:
>
>> As I pointed out - similar, but my issue was bedrock, his is water
>> table. It's never too late....
>>
>> 73,
>>
>> Joe
>> WDØM
>>
>> David Gilbert wrote:
>>
>>
>>> Your foundation is pinned to the bedrock ... his isn't.
>>>
>>> It seems to me that the opportunity for N2WQ to properly engineer his
>>> installation may have come and gone.
>>>
>>> 73,
>>> Dave AB7E
>>>
>>>
>>>
>>> Joe - WDØM wrote:
>>>
>>>
>>>
>>>> Hi Rudy,
>>>>
>>>> My situation is similar, although different. I have an above ground
>>>> base but without the water table issues. My problem was bedrock. The
>>>> tower has been up for over 5 years without a problem, and has withstood
>>>> 90 mph gusts that blew out the windows on my home.
>>>>
>>>> http://www.wd0m.com/
>>>>
>>>> Click on Ham Radio, then Tower Project. I hope this gives you some
>>>> confidence that it will work!
>>>>
>>>> 73,
>>>>
>>>> Joe
>>>> WDØM
>>>>
>>>>
>>>> Rudy Bakalov wrote:
>>>>
>>>>
>>>>
>>>>
>>>>> Looks like first post came out very difficult to read so here it is again.
>>>>>
>>>>> I have a rather complex situation that certainly can benefit from the
>>>>> collective wisdom and experience of this reflector.
>>>>>
>>>>> My property has a very high water table and as a result my builder and I
>>>>> decided to build the tower foundation mostly above ground. Specifically,
>>>>> we dug a hole, filled it with compacted gravel that is above the water
>>>>> table, covered the gravel with very thick sheets of plastic, and inserted
>>>>> 2' styrofoam boards around the base. Then we poured the concrete. As a
>>>>> result, only about 1.5' of the foundation is below ground, 3.5' are
>>>>> above. The overall dimensions are 10' x 10' x 5'.
>>>>>
>>>>> Now I wonder what are the additional engineering issues we need to
>>>>> address to make sure the foundation will last and the 90' AN Wireless
>>>>> tower will stay up. Currently, we have identified the following next
>>>>> steps:
>>>>>
>>>>> 1) Waterproof the concrete using silica based solutions, such as
>>>>> Penetron, Xypex, etc. as permanent solution against water getting into
>>>>> the foundation
>>>>>
>>>>> 2) Add extra waterproofing using tar/asphalt-like solutions to make sure
>>>>> we have extra protection should cracks emerge
>>>>>
>>>>> 3) Add styrofoam boards to prevent against freezing (it gets as cold as
>>>>> -25F in Ontario)
>>>>>
>>>>> 4) Backfill around the structure to create a mound that takes the rain
>>>>> and melting snow water away from the concrete. I have also proposed we
>>>>> layer more plastic sheets about a foot below the mound surface to make
>>>>> sure no water gets near the foundation
>>>>>
>>>>> Any further comments and suggestions will be greatly appreciated.
>>>>>
>>>>> Rudy N2WQ
>>>>>
>>>>> _______________________________________________
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> TowerTalk mailing list
>>>>> TowerTalk@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>> _______________________________________________
>>>>
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>>>>
>>>>
>>>>
>>>>
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