Patent ID: 8807876

Claim:
A device for supporting a lightly loaded structure, including a concrete slab, on highly expansive soils, said device comprising: A) a plurality of elongated polyvinyl chloride (PVC) domes, each of the plurality of elongated PVC domes comprised of one-half of a 4-inch PVC pipe cut in half lengthwise, defining a semicircular cross section, a convex side and a concave side, and positioned in an evacuation in the highly expansive soil: 1) side-by side, 2) parallel to each other and 3) separated from each other by no more than 0.33 inch, with the plurality of elongated PVC domes being positioned between the concrete slab of the lightly loaded structure and the highly expansive soil with the convex side positioned upward toward the lightly loaded structure and the concave side positioned downward toward the highly expansive soil, B) a layer of road base material located between the plurality of elongated PVC domes and the concrete slab, C) vapor barriers positioned: 1) vertically between the road base material the highly expansive soil, 2) horizontally between the plurality of elongated PVC domes and the road base material, and 3 positioned horizontally between the road base material and the concrete slab; wherein exerted pressure of the highly expansive soil against the lightly loaded structure is minimized.