Chris:
Yes you can back guy the guy post. This is getting more
complicated though and additional work. If designed
properly the cantilever elevated guy post will be
adequate.
Actually the 60/40 ratio recommended is not a bad rule
of thumb especially if you do not know the bearing value
of the site's soil or have previous experience with the
specific site.
Hank
> I have seen guy stays placed at a slight angle away from the tower and
> another guy (or extention of the guy) down at a sharp angle. Now would
> this arrangement be OK?
>
> Chris opr VE7HCB
>
>
> At 09:48 PM 2002-06-25 -0700, Hank Lonberg wrote:
> >Joe:
> >
> >I find it amazing that you can determine the soil bearing capacity at
> >the guy's site without any test or default basis.
> >
> >Based on the worst case UBC soil lateral bearing and isolated post
> >capacity equation; using a 3' hole 4' deep filled with concrete and
> >casting in a Steel member that is 6' above ground I get a capacity of
> >about 1000 pounds horizontal and say 1000 pounds vertical which equates
> >to a total guy capacity, assuming 45 degrees, of about 1400 pounds. This
> >would be the safe total load on your eyeball system given no available
> >soils information. This value is base on table 18-I-A in the 1997
> >Uniform Building Code. Your mileage will vary depending on what code you
> >use.
> >
> >It is quite possible that the total guy load on a 70 ' tower will exceed
> >this amount. Most likely if two or more guys are attached to the
> >elevated guy post.
> >
> >The weak link is not the steel member but the soil's ability to
> >withstand the load you are hoping it will resist.
> >
> >Hank Lonberg, S.E.,P.E.
> >KR7X
> >
> >
> >
> >
> >-----Original Message-----
> >From: towertalk-admin@contesting.com
> >[mailto:towertalk-admin@contesting.com] On Behalf Of Joe
> >Sent: Tuesday, June 25, 2002 7:56 PM
> >To: K7LXC@aol.com; jperalta@tampabay.rr.com; towertalk@contesting.com
> >Subject: Re: [Towertalk] Raised Guy Stays
> >
> >At 03:53 6/26/02, K7LXC@aol.com wrote:
> > >In a message dated 6/25/02 4:22:43 PM Pacific Daylight Time,
> > >jperalta@tampabay.rr.com writes:
> > >
> > > > I'm getting ready to extend the height of a 30' Rohn 25 bracketed
> >tower to
> > > > about 70' and I would like to use raised guy stays ( I think that
> >is what
> > > > they are called ) to get the guy wires above head height.
> > > The best material is I-beam (eye-beam, H-beam). It's much stronger
> >than
> > >round elevated guys.
> > >
> > > Put 60% of the guy in the ground and 40% above the ground and
> >you'll be
> > >in good shape.
> >
> >I-beams are the way to go. But let's see here, guy wires above head
> >height
> >= say 6 feet. Therefore 40% of x = 6 feet. If I recall my algebra
> >correctly
> >x would = 15 feet. Which would equate to 9 feet in the ground? I think
> >this
> >is a bit much for any 70 foot tower. Put the i-beam in the ground 4 foot
> >
> >with rebar and Johnson studs with concrete and it will hold anything you
> >
> >want to put up. A 10 foot i-beam is plenty.
> >
> >Joe - WL7E/W7
> >
> > >
> > >Cheers,
> > >Steve K7LXC
> > >TOWER TECH
> > >
> > >_______________________________________________
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> >
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> >
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>
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