Helical piers are an extendable deep foundation system with helical bearing plates welded to a central steel shaft. Loads are then transferred from the shaft to the soil through the helical bearing plates. Helical piers are available in various sizes and shapes. (Square shaft and pipe) for connections to underpinning and pile cap brackets. Helical piers are commonly used for support or correct proposed or existing foundations. Much of Northern Virginia and Washington, D.C. are intertwined with poor and problematic soils causing settlement issues with residential and commercial structures. Helical piers provide the most cost effective method for underpinning buildings. Helical piers are also used for tiebacks to existing or proposed retaining walls.