[TowerTalk] Tower buried section legs -- Buried in Concrete

[john at kk9a.com]

Or what if you have clay or rock that does not drain.  Eventually you will fill the tower legs and pea gravel with water.

John KK9A

To:	towertalk at contesting.com
Subject:	Re: [TowerTalk] Tower buried section legs -- Buried in Concrete	orBelow
From:	K6OK via TowerTalk <towertalk at contesting.com>
Reply-to:	K6OK <jvarn359 at googlemail.com>
Date:	Fri, 29 Jan 2016 12:15:29 -0800

Generic standard plans for footings by tower manufacturers are compromise
designs meant to work in most areas. They assume flat level ground and
"normal" soil. Putting a standard footing on a sidehill location is at risk
of failure if it isn't redesigned to take the slope into consideration.
Problem soils, such as organic peats, loose sandy soil, expansive clays may
need special designs to generate the needed stability. In other places with
good soil, low design wind speeds
​,​
and nonexistent ice, the standard footings can be overdesigned, resulting
in a waste of money for concrete and steel that isn't needed.

I'm a bit surprised the tower makers still publish standard designs given
the many variables that exist that make a "one size fits all" solution
difficult to achieve.

Case in point, Rohn's generic plan probably did not consider highly
aggressive acidic soil. The risk is if that pea gravel gets saturated with
acidic water, it can eat through the hot dip zinc and expose the steel,
allowing severe rust to set in and travel up the legs. Since your
contractor is knowledgeable about
​your ​
special local conditions his advice is probably right.

73 Jim K6OK