[TowerTalk] (Repost) Engineering advice on above ground foundation

[donovanf at starpower.net]

Rudy,  

In 1912, German company built an 820 foot radio tower not far from you on an ocean front island in Tuckerton, NJ.  They also had a high water table problem and built most of their tower and guy wire foundations above ground.

http://mcnally.cc/tuckmain.htm

They must have done a good job, because the huge foundations are still there!  One is right next to a house where N2GUU, N2NFH and KA2PFL live:

http://ka2pfl.tripod.com/homeeast.jpg

This one is in the middle of a street:

http://www.wikimapia.org/#lat=39.5584565&lon=-74.3706393&z=18&l=0&m=a&v=2&show=/556094/Block-in-middle-of-street-guy-anchor-for-tower&search=tuckerton

And this one too:

http://www.wikimapia.org/#lat=39.5580264&lon=-74.3705642&z=18&l=0&m=a&v=2&show=/556116/Block-in-middle-of-street-guy-wire-anchor-for-tower&search=tuckerton

73
Frank
W3LPL



---- Original message ----
>Date: Fri, 5 Jun 2009 12:27:13 -0700 (PDT)
>From: Rudy Bakalov <r_bakalov at yahoo.com>  
>Subject: [TowerTalk] (Repost) Engineering advice on above ground foundation  
>To: towertalk at contesting.com
>
>
>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
>
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