Abstract: An underpinning pile assembly for supporting a structure upon the earth has at least one steel pipe, at least one concrete pile segment positioned above the steel pipe, and a transition member interposed between the steel pipe and the concrete pile such that the load of the concrete pile is supported by the steel pipe. The steel pipe includes a plurality of steel pipe segments extending in end-to-end relationship in generally vertical alignment. A key member is received in slots formed in the respective ends of the first and second segments. The plurality of concrete pile segments includes a strand affixed in holes formed through the plurality of concrete pile segments.

Abstract: A foundation pile or pile segment is described that provides support for a structure such as a building foundation. The pile includes a generally solid body having a top end wall, a bottom end wall adapted for providing end load bearing capacity, and all around sidewalls. The sidewalls extend between the top end wall and the bottom end wall and has at least a pair of oppositely disposed spiral ridges that extend generally about the surface of the sidewalls. Further, each spiral ridge extends in a generally spiral direction from the top end wall to the bottom end wall. The spiral ridges provide an offset surface that extends generally outward from the surface of the sidewalls. The offset surfaces provide additional load bearing capacity to the foundation pile.