It might be difficult to just add another 3-4' to the base and still
maintain a good support for the tower legs. I removed a 1 cubic yard base
using a large back hoe and it went very quickly. There are also jackhammer
attachments for these machines. Lifting it out with a crane is probably no
easy task unless you dig around it first.
John KK9A
To: towertalk@contesting.com, krgoodwin@comcast.net
Subject: Re: [TowerTalk] Tower Foundation Pad Removal
From: K7LXC--- via TowerTalk <towertalk@contesting.com>
Reply-to: K7LXC@aol.com
Date: Mon, 18 Aug 2014 10:08:48 -0400 (EDT)
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
> As part of a tower replacement project, a possible plan is to remove the
existing foundation in one piece using an infinitely sized crane attached
to
the tower anchor bolts. The pad is 6.5 x 6.5 X 4 feet (6 cu yards
estimated). An effort to break the dirt from around the foundation would
be
attempted (water hose and some penetrating device inserted down the side of
the foundation pad). The remaining hole would be used for the new
foundation installing new rebar as per Rohn SSV foundation drawings (Rohn
SSV tower, 60 feet using 6N, 5N and 4N twenty foot sections). Any reason
not to consider this as a possible plan for the new tower foundation?
Sure - if you don't mind spending lots of money and time only to do
basically the same thing again.
It's easy enough to drill new holes in the concrete for new anchor
bolts. If the base isn't big enough, you can enlarge the hole on 2 sides
and
add additional rebar by drilling into the existing base and epoxying the
rebar in place. BTW the above 6 yards of concrete will weigh about 24,000#.
What is your proposed base? Are you doing this for a different rebar
schedule or what? I don't see a good reason for doing this in the info
presented.
> Secondary question: Do you tie the tower and the rebar into a ground
connection at the bottom of the foundation? Years ago one isolated the
rebar but I think the thoughts today are just the opposite.
Putting an Ufer ground in the base is a fine idea. Google it or dive
into the TT archives for more info.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for amateurs
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