Abstract: A method and apparatus used to increase the stiffness characteristic of soil to improve its ability to support a structures and to provide a tie-back anchoring force. The apparatus includes an anchor having helixes thereon is rotated into the ground. The helical anchor is hollow and includes multiple perforated holes along its length and about its perimeter. Once, the anchor is drilled into the ground, pressurized grout is injected therein. The grout is forced through the helical anchor and out through the perforated holes. The grout fills any voids along the sides of the anchor and stiffens the surrounding soil. Once the grout hardens, it may be used in a tie-back application or to support new and old construction or the like. The grout surrounding the anchor increases its lateral support and prevents deflection thereof.

Abstract: A helical outrigger apparatus attached to an underpinning drive assembly for exerting an auxiliary anchoring force upon the underpinning drive assembly while sinking piers, pilings, screw-type underpinnings and the like. The piers, pilings, etc. are used to lift and support new and existing structures. The anchoring force is used to supplement a principal anchoring force provided by a dead weight of the structure. The helical outrigger apparatus fastens to a pier bracket which supports the underpinning drive assembly during operation. The helical outrigger apparatus includes a screw-type helical anchor that is sunk into the ground temporarily. The apparatus includes at least one outrigger fastened to the pier bracket. Multiple helical outriggers with anchors may be located evenly along the drive assembly. Each outrigger assembly includes an arm that is pivotally and telescopically moveable to facilitate connection between the pier bracket and the corresponding helical anchor.