Helical piles, also known as screw piles, are a time-tested solution that support structures built on less-than-ideal soil conditions. Each helical pile is built from a round steel shaft and several helical blades that extend outward. When installed, the helical design creates an anchoring effect against compressive and tensile loads. The piles significantly strengthen foundations—especially for structures built on soft, unstable soil.
Below, we provide a comprehensive overview of helical piles for those who seek helical contractors:
- The history of helical piles
- Where are helical piles used?
- Types of helical pile designs
- How are helical piles installed?
- What are the benefits of using helical piles?
- Finding the right excavation contractor for installation
Where Did Helical Piles Originate?
Helical piles originated nearly 200 years ago. First invented in the 1830’s by Alexander Mitchell, these early designs supported marine structures, such as lighthouses or boat moorings, in the challenging ocean environment.
Over time, engineers realized that helical piles had mainland applications, but the labor required to install deep foundation options put them in and out of fashion over the years. Notably, steam-powered pile driving in the early 1900’s reduced the popularity of labor-intensive helical piles, although it wasn’t long before helical piles made a resurgence.
These days, helical piles are popular again and are often thought of as a “new” strategy for foundation design, given that many engineers and excavators were undertrained on their applications. As it turns out, helical piles have a broad range of applications that make them a great choice for many installations.
Where Are Helical Piles Used?
Helical piles are versatile and applied in a wide range of industries. Let’s explore some common uses for helical piles across different sectors.
Helical piles are a common choice for foundations of single-family homes, townhouses, and apartments. On the commercial side, they can be used for office builds, retail spaces, and other commercial structures—including factories, manufacturing plants, and other industrial facilities.
Helical piles are often seen in infrastructure, such as for bridge abutments and overpass supports. They can also be used to boost stability in retaining walls, support boardwalks along coastlines, or other structures that require stabilization.
Another application of these tools is in the energy sector. Helical piles are a solid foundation system for solar panel arrays because they anchor them to the ground. They’re commonly seen in wind turbines, which must have strong, stable foundations to withstand high wind forces.
Given that helical piles were designed for aqueous applications, it’s no surprise that they’re a longstanding choice for marine jobs. Helical piles provide stable support for docks, piers, marinas, and waterfront structures, and they help reinforce coastal protection structures against erosion caused by waves or tides.
These examples demonstrate just how useful helical piles are as a foundation system. Whether it’s residential, commercial, infrastructure, energy, or marine construction, helical piles can do a lot—provided, of course, that they’re designed the right way.
Types of Helical Piles
As helical pile systems are used to provide stability and support to structures, it stands to reason that different variations exist. The different types of helical pile designs include round shaft, square shaft, and combination piles—each with different characteristics. Let’s take a closer look at each type.
- Round Shaft Helical Piles: These piles feature a round-shaped shaft with one or more helical blades attached to it. These blades, also known as helices or flights, are spaced evenly along the length of the shaft. Round shaft helical piles are versatile and can be used to support structures across various soil conditions, although they work best in loose, weak soils.
- Square Shaft Helical Piles: As the name suggests, square shaft helical piles have a square-shaped central bar with welded flat plates that resemble helical blades. The flat plates create additional bearing capacity when they displace soil laterally during installation, making square shaft piles a good choice for hard and rocky soils.
- Combination Helical Piles: This type is built with a square shaft and rounded blades that give the pile a coordination of benefits not found in either option described above. Combination piles are ideal for strata with layers of hard soil located deep below looser, surface soils. However, due to their unique design, combination piles tend to be less affordable than other options.
How Are Helical Piles Installed?
Helical piles are installed through a multi-step process that uses several types of hydraulic equipment, depending on the project. Smaller-scale and lightweight helical piles can be installed with portable torsion bars, skid steers, or mini excavators, while high-capacity piles require large excavators powerful enough to drive the pile into the ground.
The installation process follows several steps:
- Review the site to evaluate soil conditions and determine which helical pile design is appropriate.
- Select and mobilize equipment based on the size of the piles and project scope
- Position and align piles at their designated locations
- Apply torque to advance the pile and penetrate the strata
- Continue rotating until the correct depth is reached
- Verify and adjust the piles, with additional load testing and fine-tuning as needed
- Document and provide final reports
For most projects, helical piles will be installed 10 to 25 feet below the soil, although the exact parameters will depend on the project. Regardless of what strategies are used, a qualified piling contractor should perform static load testing to confirm adherence to settlement criteria and document all criteria in a piling report. Rather than simply search for helical contractors near me, make sure that the contractor of choice follows these processes to reduce liability and be sure that all project goals are met.
The Benefits of Helical Piles
Now that you know a lot about helical piles and how to install them, you might wonder what specific benefits helical piles bring when installed by a qualified excavation contractor.
Permanent & Temporary Applications
Helical piles cater to both permanent and temporary applications and provide a versatile foundation solution for many types of construction projects.
Helical piles offer the advantage of easy removal using the same equipment employed during installation. This streamlined process reduces environmental impact and makes the project more efficient.
Reusable for Sustainability
Helical piles are reusable, so they contribute to sustainability in construction practices. The ability to repurpose these piles for multiple projects minimizes material waste and promotes environmental responsibility.
Can Be Loaded Instantly
Helical piles support immediate loading, which allows for instant application of structural loads. This feature reduces program time and project costs by accelerating construction timelines.
Can Be Installed in All Weather Conditions
Helical piles can be installed in all weather conditions, which leads to construction freedom. This adaptability ensures that projects can progress regardless of rain, snow, or other weather challenges.
Helical pile installation generates no spoil. The absence of excavated material simplifies the construction process, eliminates the need for disposal, and helps workers maintain a clean and organized worksite.
Can Be Installed in Contaminated Soils
Helical piles excel in contaminated soil conditions and offer a robust foundation solution where other methods may be impractical. Their installation minimizes soil disturbance and makes them a strong choice for environmentally sensitive areas.
Can Be Installed in Most Soil Conditions
Helical piles are versatile because they can be installed in a wide range of soil conditions. They can be installed in sandy, clayey, or rocky terrains because they adapt to varying soil types and provide consistent performance.
No Noise or Vibration During Installation
Helical pile installation is silent and vibration-free. This is particularly beneficial in urban or sensitive environments where noise and ground disturbance are concerns.
Find the Best Helical Pile Installers Near Me
With all of the above in mind, it’s important to recognize that, for most projects, helical pile installation is just one part of the equation. Those who seek helical pile installation should vet their options and make sure that their contractor can handle all essential tasks in the project workflow, including excavation, demolition, and debris clearing.
By entrusting the project to a qualified excavation contractor who can do it all, businesses can save time, effort, and avoid the need to coordinate multiple vendors. There’s no better way to ensure that all project elements are seamlessly integrated and executed with precision.
Need help with a helical pile project? Contact Rock Hard Excavation and see the difference that generations of experience can make!