The present invention is a support structure including elongate hollow cylinder and flat plates secured thereto. A first rigid flat plate is horizontally disposed in overlying relation to each hollow cylinder and a second rigid flat plate is horizontally disposed in underlying relation to each hollow cylinder. Stress-distributing strengthening members are circumferentially positioned about the hollow cylinder and secured to their associated rigid flat plates. A key may extend from a first end of each hollow cylinder and a mating socket may be formed in a second end of each hollow cylinder to facilitate end-to-end interconnection of a plurality of hollow cylinders.