Cob: foundation idea

[Shawn Honeychurch]

HI All,
I have an idea about a foundation method for below a cob wall that I'd like
to bounce off anyone out there in the know.  I haven't heard of this being
done, but am not sure why not.  I live on Vancouver Island, BC, where it
doesn't get that cold in the winter but it is damp.
I only need to dig about a foot down to get below the frost line.  I plan to
have a large overhang on my roof (about 8') so the walls stay dry in the
rainy season.  If I dug down a foot, starting 8' out from where the cob
walls will be, and I dig out a big square around and under where the house
will be, couldn't I just lay drainage tile in the bottom and then fill in my
foundation hole with gravel?  If I built a small wood/stone retaining wall
at the edge of the hole, I could bring the gravel up to 1' above ground
level.  If this was compacted, couldn't I just start my cob wall ontop of
this gravel layer?  It seems to me the gravel would keep moisture away from
the cob wall and yet act as a slightly supple buffer in the case of an
earthquake.  I've done a small "sketch" below.  Please tell me what you
think!
-- Robynn
			!  !			   !	! < cob wall, resting on
			!  !			   !	!  packed gravel
			!__!			   !__!
ground	!.....................................! < stone edging
------------! ...............gravel...............! -------
		!.....................................!
		!_____O_______________________O_______!

			  ^ drainage pipes