A small area of my yard has a bounce to it... stepping on this area the ground will sink and come back up to it's resting place.. standing with feet about 3 feet apart and push down with one foot the other will be pushed up with the ground movement...
This was under my patio slabs. I dug down and found a very large construction tape along with bricks buried under the ground. About 3 feet down.
I removed the debris and re-filled the hole. The ground still has a bonce to it, but continues to sink.
The soil is heavy clay. I thought the tarp was protecting voids in the soil from filling in during settling and have removed the tarp would have corrected the problem.
Any idea's of what the problem is.