On Sun, 2 May 2010 09:32:46 +0100, Muddy Horse wrote:

1) Fill the hole in with compacted soil. Presumably this would have to
be repeated every few years.

No different to what you have the horses will carve it up the first
time the go in/out...

2) Extend the concrete ramp with more concrete. This might be hard work
if DIYed, and expensive if done professionally. Any ideas on how the
ramp should be constructed?

That would work but unless you extend the end and cover it with soil
you'll just move the step to the end of the new concrete. Even
covered with soil it might not last that long.

3) Filling the hole with gravel or similar is not acceptable, because it
would injure the horses' feet.

See the other suggestion of compacted MOT1 covered in soil. Dig out
to firmish subsoil, (ie get rid of the mud/stuff that has been cut
up) backfill with MOT1 and hire a whacker plate to compact it. The
ground forces from horses hooves are high, the MOT1 will need to be
very well compacted. Cover with the spoil you dug out and whack that
as well.

4) Constructing a ramp from wooden sleepers might work, but slipperiness
would be a problem.

Yeah, even if you routed large grooves in the wood the edges wouldn't
last long.

--
Cheers
Dave.