At 11:36 AM 10/12/2006, Michael Baker wrote:
> When have you EVER seen a tower foundation FAIL? I mean deteriorate
>to the point it wouldn't work as a tower base anymore.
I had a tower base "fail" about 20 years ago. It may depend on what people
think "fail" means.
During Hurricane Gloria in 1985, I had a 4-6" tree limb fall on a lower guy
anchor of a 90' Rohn 45 tower guyed at 30/60/90' and with 20/15/10 monobanders
and a couple of inverted Vees on it..
The tree limb caused enough down pressure to actually bend one leg of the tower
- it bent outward several inches (about 4' from the ground). That in turn
caused a guy anchor on the other side to pull out of the ground (a screw in
anchor that should have been in concrete). So the tower started to sway and
then titled about 20 degrees onto some nearby trees. My wife and I grabbed
the loose anchor and tied it around a nearby tree and I think that kept things
from completely failing.
The next day after inspecting the damage I noticed the ground was broken about
two feet out from the tower, almost all around the base. What had apparently
happened is that as the tower leaned over into the trees, it had enough
leverage to move the entire base within the (somewhat sandy) soil. To me that
was a foundation failure. The concrete didn't deteriorate though.
I was able to fix the tower - I put in a concrete anchor, then had a
professional tower crew come and untangle the tower from the trees, get it back
vertical, and I think the base moved "back" to where it started. I also had a
welder come in a few weeks later and remove the bent portion of the tower leg
and put in a replacement.
I moved a few years later so the base was discarded. That tower section is
still in use at the present QTH.
-- Tom
--------------------------------------------------------------------------------------------------------------------
e-mail: frenaye@pcnet.com YCCC --> http://www.yccc.org/
Tom Frenaye, K1KI, P O Box J, West Suffield CT 06093 Phone: 860-668-5444
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