US Patent 7494299 Piling apparatus having rotary drive

An in-situ pile apparatus 10 includes a helical anchor to which a plurality of elongated generally cylindrically shaped sections can be added. Each of the sections has a specially shaped end portion for connecting to another section. An internal drive is positioned in sections inside the bore of each of the connectable pile sections. The internal drive includes enlarged sections that fit at the joint between pile sections. In one embodiment, the internal drive can be removed to leave a rod behind that defines reinforcement for an added material such as concrete. The rod also allows for a tension rod connection from the anchor tip to an upper portion attachment point.