Helical piles, otherwise known as screw piles or helical anchors, provide support to large structures. Because these piles are deep underground, they have enhanced abilities to support large weights from below. If you know about helical piles, this isn’t news to you. However, did you know there are four types of helical piles?
Here are the four different types of helical piles:
- Square shaft
- Grouted shaft
- Round shaft
- Combo shaft
Below, we will explain what differentiates each type of helical pile. We will also present common uses for these helical piles.
#1: Square Shaft
Square shafts are typically best for usage in stony soils. The rocky consistency of the earth means they are harder to press through. That comes from the narrow width of the steel, allowing it to catch less soil pressure. It’s also easy for the rocky soil to help “hug” the support beam.
As a result of the narrow beams, they aren’t quite as effective in softer soils. The narrow width makes this less sturdy, and soft soils won’t aid in support.
These shafts are characterized by being square-shaped and maintaining a consistent width throughout.
#2: Grouted Shaft
A grouted shaft is a square or round post with fittings made of steel or PVC to assist in support. These fittings are known as grout plates. The extra support seeks to address the disadvantages of square post helical piles by increasing buckling support. They also provide additional support to round shafts with cumbersome structures.
In many cases, they save money over round shaft helical piles because the square portion is still just as narrow. However, grout plates are difficult to force through rocky soil.
Also, grout mixing is typically on-site, making this option not suitable for wet conditions.
#3: Round Shaft
Round shaft helical piles are much broader than their square counterparts. As a result, they provide the most available resistance against buckling. If you have a heavy structure, these are going to come up in conversation.
The larger surface area gives the large-diameter space problems in getting through stony soils. These are ideal for soft soils, as they can easily penetrate the space.
You can also have grouting in this pipe, but only in soft soil locations.
#4: Combo Pipes
Combo helical piles are explicitly for conditions where you have multiple soil layers at differing hardness. With this, you can take advantage of the penetrating abilities. In combination with the sturdiness of round, you have an excellent sturdiness potential.
With this in mind, the combination is not suitable outside of specific applications. Don’t expect to use them in situations where you have exclusively soft or rocky soil. They are more likely to be used in areas low to sea level or with a high water table.
High water tables mean that the groundwater is high enough to create softer soil conditions below.
With this short guide on helical piles, we hope that you have a better idea of what to expect for your project. If you need solutions for your helical pile projects, don’t be afraid to contact us for more information!