A helical pile is a steel foundation support with helical, screw-like blades along its shaft, mechanically twisted into the ground rather than hammered or drilled, until it reaches soil capable of bearing the intended load. It’s widely used for both new construction and foundation repair, especially where access is limited or vibration must be minimized.
Installers can measure the torque required to turn the pile as it advances, which correlates closely with the soil’s actual bearing capacity at that depth.
What Does Installing a Helical Pile Involve?
- A steel shaft with helical bearing plates
- Hydraulic equipment to rotate the pile into the ground
- Torque monitoring during installation to confirm bearing capacity
- A bracket connecting the pile to the structure above
Why Are Helical Piles Important?
Because helical piles are screwed in rather than driven with impact force, they produce minimal vibration and noise, making them a practical choice near existing foundations or in urban settings where a driven pile might risk disturbing neighboring structures. They’re also commonly used for foundation underpinning repairs, since compact equipment can install them in tight crawl spaces or backyards where larger pile-driving rigs can’t operate.
This combination of precision and small equipment footprint has made helical piles one of the most widely used foundation repair methods for homes experiencing settlement on expansive or unstable soil. Manufacturers typically provide published torque-to-capacity correlations for their specific helical pile products, giving engineers a reliable way to verify load capacity in the field without needing a separate load test for every installation.
Helical Pile vs. Driven Pile
A driven pile is installed with impact or vibratory force, while a helical pile is twisted into the ground using torque, similar to a large screw. Helical piles generally suit smaller sites and repair work, while driven piles are more common on larger new-construction projects.