The first thing to consider is just what wpowokal said. Soil
composition. If it's swamp or loose sand, I'd much rather have
something the size of an Army tank at the bottom of the hole
than just an 8 or 12 inch rotor.
If you have access to a metal recycler (scrap metal yard), maybe
you can get pieces of old railroad track, or an old mobile home
frame, or truck frame. I think one of the Dan's even used a whole
engine as an anchor base. For a deadman, think weight and/or area.
If you take a piece of 1 inch pipe and weld it
in the center of a 3 or 4 foot piece of I beam (Put an eye on the other
end of the pipe for the guy wires), then bury that 3 or 4 feet down,
it will take quite a bit of force to pull that out of the ground.
We are still assuming you're not in the swamp or loose sand.
Then, if you have large rocks available, pile them on top of the
deadman and then your concrete. The concrete will make the rocks
into one huge rock. Then the rest of your backfill. No more than
4-6 inches of fill at a time. Then tamp (compact) the back fill.
Then another 4-6 inches, then tamp. Also you cannot tamp dry dirt.
You cannot tamp mud either. It must be moist in order to compact.
It's just moist enough if you can squeeze it into a ball with your
hand (doesn't fall apart or squirt out through your fingers).
Ralph
