John:
The key point in your post is that you had a P.E. review
it. That individual has experience with the soil type
and values in your area and could make an engineering
estimate of the soil capacity.. That is key, without
that knowledge or expertise available it would be
prudent to use the lower values I assumed.
Your installation is pretty substantial and I
congratulate you on being wise and have someone with
expertise review it.
As far as the original post... As someone else already
stated, too little information on actual system and
loading.. any advice even mine is worth what it cost.
73
Hank
> In a message dated 6/25/2002 11:50:30 PM Central Daylight Time,
> kr7x@attbi.com writes:
>
>
> > The weak link is not the steel member but the soil's ability to
> > withstand the load you are hoping it will resist.
> >
> >
>
> Good points, however, there many soil types and installations that will
> handle a huge load. I have a very loaded up 110' Rohn 55 Tower (prox 25 sq
> ft. antennas) supported by 3 elevated guy posts which are 8" double wall
> pipe. All are 5' in the ground with two being 8' out and one being 4' out.
> The difference with mine from what I've heard is that the concrete base, 3' x
> 3' x 4' deep is actually 5' down. There is one foot of dirt over all so that
> they can be cut off when I move on. I stuffed about 3' of wire mesh down
> from the top and core filled to that point to keep out water. The 13' pipe
> pieces weighed about 450#, so it was quite a trick getting them in the middle
> of the holes. Welded on 1/2" steel plate ( 2"- 8") for guy connections
>
> The plus with round pipe is that it looks a heck of lot better than "I" beam
> when all painted up. Also there is little to gain by tilting it except that
> it looks terrible! I had a PE pal do some quick checks in my somewhat
> rocky/clay soil, and he said I was fine. It has been up for several years
> and hit by several big storms. Several damaged antennas, but All 3 pipes
> are PERFECTLY straight.
>
> The key, of course, is soil type and depth--but no need for overkill.
>
> John, N0IJ
> Duluth, MN
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