Helical Foundations

Helical foundation systems are a combination of steel components designed to resist axial compression, axial tension, and/or lateral loads from commercial and residential structures. The systems consist of a central shaft, one or more helix-shaped bearing plates, and a load transfer bracket and is advanced into the ground via the application of torque.

A standard helical configuration consists of helix plates that are welded to the first section installed. The helix plates typically have a 3-inch pitch which provides a downward thrust that advances the helical into the soil. Extension sections are then added, with or without helix plates, and the helical is advanced to competent load bearing soil and installation torque. Lastly, a load transfer bracket is attached to the last extension for the attachment to structures, either for new construction or retrofit applications.

Types of Helical Systems

Helical Piles can resist both axial compression and tension loads, in addition to resisting lateral loads, and are typically used to support the foundations for new construction projects. Helical Piles used in retrofit applications to support existing structures typically resist axial compression loads only.

Helical Tiebacks and Helical Soil Nails are different types of helical systems that are typically used to provide support for new or existing retaining walls or for earth retention. Helical tiebacks are commonly used to provide lateral support on retaining walls, foundation walls, sheet pile walls, and soldier pile walls. Soil nails are typically installed in a closely spaced grid pattern to reinforce the soil mass and create an internally stable gravity wall/retaining system.

HeliCast^™ Grouted Pile System

The Foundation Supportworks HeliCast^™ grouted pile system utilizes the same components as helical piles; however, the HeliCast^™ system also includes a grout column around the inner central shaft. This grouted pile system can typically generate larger capacities than a standard helical pile since the compression capacity is generated from both the end-bearing of the helix plates and the frictional resistance of the grout column.