I want to build a 100' x 60' building on my property. The dirt is black and is great for growing vegetables and crops. The biggest problem I assume would be the foundation. The black dirt is more than 6' deep and is very soft. I had a mobile home on the property for over a year, that was sitting on just tires and a couple of blocks and it didn't settle to much. I have used a floor jack to get the blocks under the mobile home, so the dirt can sustain some load. When I use a backhoe and put the pans down, you can feel the ground shake, just to give you an idea what the soil is like. Any insight on this would be greatly appreciated. Thank you