Helical piles, also known as screw piles, are constructed using steel shafts with helical flights (helix/helices) of various sizes to suit the site specific ground conditions.

Helical screw piles illustration

Common uses

Structural support (compression or tension) for both permanent and temporary structures
Underpin existing foundations
Bridges (abutments, columns)
Telecommunication masts/platforms
Electrical equipment, pylons and poles
Buildings/modular buildings
Rail structures (signalling, platforms, overhead line equipment)
Highways structures (signage)
Temporary/permanent seating (stands)
Anchors (back stays/tension guys)
Retaining walls, flood defences
Wind turbines
Solar farms


Piles are generally installed using standard tracked or wheeled excavators with a torque motor attachment which monitors the torque achieved during installation to verify the design.

Helical Piles are advanced to the predetermined (design) bearing strata by rotating the steel shafts with the torque motor attached to the excavator plant/rig. Multiple steel sections are connected via a bolted connection and sections are added to complete the total pile depth.

Helical flights strategically designed along the shaft penetrate the soil without augering, displacing the soil,whilst the torque is carefully monitored as the pile advances. The final torque reading is taken over the last 1m of advancement to ensure the pile is achieving the required design before terminating at the correct datum level.

Helical Piles are able to restrain unfactored (SWL) axial loads of up to 300kN, uplift loads of up to 200kN subject to the ground conditions and lateral loads of up to 25kN. Higher lateral forces can be restrained with the addition of a concrete collar to the top of the pile head.

A detailed understanding of the subsurface conditions (especially soil strata type, strata levels and strength (SPT ‘N’ Values) to depth is necessary to properly interpret the required design and torque capacities.

On completion, the top of the pile can be connected in various ways to the structure by a direct steel flange plate connection or plate/rebar connection to concrete.


Permanent or temporary applications
Removable using the same equipment and method reducing environmental impact
Reusable so a sustainable product
Can be loaded instantly, reducing programme time and cost
Can be installed in all weather conditions
No spoil
Can be installed in contaminated soils
Can be installed in most soil conditions
No noise or vibration during installation

Quality assurance

Keller is able call upon a wealth of knowledge and experience to offer and successfully deliver the optimum solution. Static load testing can be done to monitor and confirm performance and that the required settlement criteria is met.