Are Helical Piles Suitable for All Soil Types?

Helical piles are a popular foundation solution for a wide range of applications, from small residential structures to large commercial buildings. One of the key benefits of helical piles is their versatility, as they can be used in a variety of soil types and site conditions. Let’s explore the factors that determine the suitability of helical piles for different soil types and site conditions and provide some guidance on when helical piles may be the best foundation solution.

One of the primary considerations when selecting a foundation system is the soil type at the project site. Helical piles are particularly well-suited to soils with poor load-bearing capacity or high water tables, which can pose challenges for other types of foundations. The helical design of these piles allows them to be screwed deep into the soil, creating a strong, stable foundation. However, there are some soil types that may not be suitable for helical piles, including extremely rocky or hard soils that cannot be penetrated by the pile.

Here are some soil types where helical piles are often used:

1. Clay soils: Helical piles are an excellent choice for clay soils, which can be prone to settling and instability. The screw-like design of the pile allows it to create a strong, stable foundation in the clay, preventing settling and ensuring long-term stability.

2. Sandy soils: Sandy soils can also benefit from the use of helical piles, particularly if they are located near bodies of water or in areas with high water tables. Helical piles can be screwed deep into the sand, creating a stable foundation that resists the effects of water.

3. Soft soils: If the site has soft or loose soils, helical piles can be an effective solution for creating a stable foundation. The piles can be screwed into the soil to create a solid, stable foundation, even in areas with poor load-bearing capacity.

4. Bedrock: If bedrock is encountered before the pile is drilled below the frost line (usually 4 to 5 feet deep in Ottawa), a bedrock anchor would need to be performed because standard helical piles are not meant to drill through bedrock. With an excavator, the bedrock has to be exposed so steel plates can be anchored on the bedrock and piles welded on the steel plates. Helical piles that are anchored in bedrock allows it to resist to high horizontal and vertical forces, making it an excellent choice for anchoring structures to bedrock.

In summary, helical piles are a versatile foundation solution that can be used in a variety of soil types and site conditions. While there are some factors that may make helical piles less suitable for certain projects, they are a reliable and effective foundation option for many applications. If you're considering helical piles for your project, be sure to consult with an expert helical pile installer to determine the best foundation solution for your specific needs.