My driveway is made of dirt, gravel and thin layer of asphalt. There is a 6' x15' spot on the driveway when you walk on it, it's very soft to the point of the surface moving up and down like your walking on a mattress. I'm at a loss as to who or how this can be diagnosed or fix. I know that there is water soaked soil under the surface causing this any ideas ??? the enclosed area in the red outline is the squicy ground