[TowerTalk] Pad and Pier Foundations

[K7LXC@aol.com]

In a message dated 7/10/2005 10:39:28 PM Pacific Daylight Time, 
towertalk-request at contesting.com writes:

>  The ability to dig an "undercut" hole no doubt depends on the soil. I 
gave a local concrete contractor the AN Wireless foundation plan, and he 
said there was no way to dig such a hole. He said the only way to do a 
pad and pier foundation around here would be to dig the hole the size of 
the pad, construct a form the size of the pier, then backfill.

    A couple of comments about the Trylon base design. First, IMO it's a 
stupid design. I'm sure there's a valid engineering reason to have the bottom 
belled-out but it's not only dangerous to be in a hole that deep but it's also 
illegal per OSHA rules to be that deep in a hole without being shored up. This 
was designed by an engineer in an air-conditioned office that never has to 
install one of them. In many cases the soil won't allow it anyway. 

    Second, the design calls for 7 yards of concrete. Make the hole bigger 
(usually happens when you use a backhoe anyway), put in a little more concrete, 
and you're good to go. The Trylon design is one-size-fits-all so there's some 
engineering overhead already built in. 

Cheers,
Steve    K7LXC
TOWER TECH -
A professional tower erector, not an engineer
Cell: 206-890-4188