Lest anyone miss the point of the multiple posts....
it's the SOIL that matters most. Every example offered
was with a gravel/clay soil. From his e-mail address,
Julio is in Florida. Sandy soil, probably no clay.
Probably high water table. The SHAPE of the anchor structure
probably matters more than the mass, in that case.
Everyone of the PE's who waded in on this said the same thing....
get a PE to do the analysis properly. That's the only right
answer. At a minimum, find one who's a ham, and get him to
show you how to do the analysis properly....if he doesn't have
to put his seal on it for your building permit, it'll save you a lot.
Towers are a lot like sailboats. When the ground tackle is
big enough, you get to sleep nights.
Jim Jarvis, N2EA