[TowerTalk] Square Hole or Round Hole for Self Supporter?

[jimlux]

On 1/20/18 11:01 AM, Richard Thorne wrote:
> I have an HDX-589.  I'm in the planning stages for getting the tower 
> installed.
> 
> I ran across a driller yesterday that can drill the 10' deep hole to a 
> diameter of 7'  (87" to be exact).
> 
> We have excellent soil here for self supporting towers, caliche. Digging 
> by hand is out and using a back hoe would probably make an over size hole.
> 
> Is there a reason not to use a cylinder vs a square hole?
> 


Nope.. Here in Southern California, there's a big business in drilling 
holes to be used as foundations for things like traffic lights (huge 
bending moment) - you can drill a 4 foot diameter 20 foot deep hole 
where the sidewalk is, lower a rebar cage in, and fill it with concrete 
to make a very solid pier for the traffic light to bolt to.

The whole "cube" is mostly because it's easy to dig by hand/backhoe, and 
easy to calculate.