Abstract: A concrete slab which has settled is stabilized and may even be lifted by forcing a pier through the slab and into the underlying soil and then attaching the pier at its upper end to the slab. To this end a vertical hole is drilled through the slab as is a smaller oblique hole, with the latter intersecting and passing through the former. Then a jacking unit is attached to the upper surface of the slab around the vertical hole. The jacking unit forces a succession pier sections through the vertical hole and into the underlying soil, with these sections being fitted together end-to-end to form a pier. In time significant resistance is encountered, and at this point, while the jacking unit exerts a downwardly directed force on the pier and an upwardly directed counterforce on the slab, a hole is drilled through the portion of the pier that is within the slab, this being done by using the oblique hole in the slab as a guide for the drill bit.