Thought I would post some photos and share the experience.
My wife and I built this mega double walled earthbag foundation for a balecob house and it is stronger than I had ever hoped for. At one point I backed my 3/4 ton truck with hitch and carrying two yards of clay into it and it ripped the bag open without any ill effect. This was my first attempt at earthbagging and it was hard as hell, but amazing to build with. From the photos you can see the gap we left between the bags to add in insulation.