I would hate to do the rebar for it. A 25' long rebar cage that has to
be positioned in the middle of the hole and have clearance to the sides
all around. and pouring would be a problem also, free fall is probably
ok for a normal depth foundation, but for 25'? rohn warns about not
letting freefall concrete hit the side of the hole or moving the rebar,
that could be real hard to control 25' down. While it may have a great
overturning moment I would worry about bending forces on that small of a
cross section unless extra care is taken with the rebar. Also, where is
this that you can drill that deep and not hit ground water??
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of Jerry Keller
> Sent: Sunday, October 05, 2003 17:21
> To: David Giuliani; towertalk@contesting.com
> Subject: Re: [TowerTalk] The tower base is poured BUT...
>
> OK, maybe my ignorance is showing, but does anyone else think it a bit
> preposterous for an engineer to recommend digging a 25 foot deep hole
for
> a tower base? If the soil content would allow augering a 25 foot deep
hole
> only 2 feet in diameter, wouldn't it cave in long before it got that
deep?
> Are there even 2 foot diameter truck-mounted augers available 25 feet
> long? There's something about this idea that just seems wrong... but
then
> I'm no engineer. Any thoughts? Jerry K3BZ
> ----- Original Message -----
> From: David Giuliani
> To: towertalk@contesting.com
> Sent: Sunday, October 05, 2003 12:23 PM
> Subject: RE: [TowerTalk] The tower base is poured BUT...
>
>
>
> The more I read about this, the more I'm liking my emerging plan to
dig
> a
> hole with a truck mounted auger rig -- no forms, no backfilling,
> relatively
> small diameter surface. We're looking at a 2' diameter hole, 25'
deep.
> Relatively simple rebar for the lower 80%. Requires <3 cubic yards
of
> concrete. See "deep base for MA-550" for this thread.
>
> David Giuliani, WA6PXX
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com]On Behalf Of K7LXC@aol.com
> Sent: Sunday, October 05, 2003 6:46 AM
> To: k1ttt@arrl.net; towertalk@contesting.com
> Subject: Re: [TowerTalk] The tower base is poured BUT...
>
>
> In a message dated 10/4/03 9:54:13 AM Pacific Daylight Time,
> k1ttt@arrl.net
> writes:
>
> > Doesn't anyone use forms any more???
>
> What for? I assume you mean below grade. The concrete is
supposed to
> be
> poured into 'undisturbed' earth.
>
> An exception would be when the walls keep sloughing; then the
forms
> would
> be necessary but you have to be real careful to backfill after you
> remove
> the
> forms and tamp the backfilled dirt.
>
> Cheers,
> Steve K7LXC
> TOWER TECH -
> Professional tower services for commercial and amateur
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041
with
> any
> questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041
with
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041
with
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|