standing block stability

[Norman Watts <Norman_Watts@zzzzzzz>]

Hi Simon,

I'm no engineer either, but the way I figure the stability is by
drawing a line from the center of mass to the outer edge at the base.
 From the vertical this line subtends an angle of 14 degrees. The is
also the tip angle. If the block were sitting on a totally hard
surface tipping a weight of almost 3 tons up 14 degrees would make
the thing pretty stable. However, in a meadow, even a hard-packed,
well-drained one, I don't know. The ground pressure I mentioned
earlier isn't too great but I can't get away from the feeling that
the ground might shift a bit, and as the angle increases the
instability would grow.

My idea certainly is to put the block on some kind of a temporary
base (its not supposed to be permanent there). But what? I've seen
pictures of huge blocks sitting up on railway ties, and while that
gets the block of the ground and also allows getting something under
it later on, it only increases the stability in one axis. At the same
time it raises the block and decreases the stability in the other
axis. So its a trade off. One option would be doweling to the
reinforced concrete footing as you suggest, but that seems excessive
for something temporary. And how would you get it off later on?

n