When engineering the ideal helical pile design for your foundational application, there are many important factors to consider. One of them is shape. Here’s some insight on round vs. square helical pile shafts, so you can decide which might option be best suited for your project.

Round vs. Square Helical Pile Shaft

There are two main helical pile shaft designs: round and square. Neither shape is overwhelmingly “better” than the other — it just depends on your project’s conditions and goals.

Below, we’ll list each type of helical pile design, along with its typical sizes, advantages, disadvantages, and applications.

Round-Shaft Helical Piles

Round-shaft helical piles are made of steel tubes with a circular, hollow cross-sections. They’re typically wider in diameter than most square-shaft piles. This makes round-shaft helical piles the best type of helical pile shaft for resisting lateral loads.

You can see the round shape of these helical piles from one of our recent projects:

Sizes

Typical sizes for round-shaft helical piles are: 2.875”, 3.5”, 4.5”, 6”, 8”, and 10”+.

Advantages

Round-shaft helical piles bring the following advantages:

• Ideal for soft soils
• Able to support large lateral loads
• Higher installation torque rating
• Can be filled with grout for boosted structural durability

Disadvantages

Because round-shaft helical piles generally have larger diameters than square-shaft piles, they can be more difficult to insert and stabilize in very dense or rocky soils.

Suggested Applications

Round-shaft helical piles are most frequently utilized in new construction settings where high lateral loading and/or buckling are concerns.

Square-Shaft Helical Piles

Square-shaft helical piles are solid, square bars made of steel. They’re commonly smaller in diameter than round-shaft helical piles, but can still deliver a great capacity-to-torque ratio. Plus, they offer more stability and ease of installation in certain environmental conditions.

You can see the square shaft of these helical piles from one of our recent projects:

Sizes

Typical sizes for square-shaft helical piles are: 1.5”, 1.75”, 2”, and 2.25”.

Advantages

Square-shaft helical piles have their own set of advantages, including:

• Ideal for very hard, dense, or rocky soils
• Better at penetrating without causing ground damage
• Able to support large axial compressive loads

Disadvantages

Square-shaft helical piles don’t have as much lateral capacity and can’t defend as much against buckling.

Suggested Applications

Due to their unique capabilities and shortcomings, square-shaft helical piles are ideal for projects with rocky or firm soil conditions. They should be avoided in situations where high lateral loading or buckling resistance is necessary.

Combo Helical Piles

In some cases, a combo pile is best. A combo pile is a combination of a round-shaft and a square-shaft pile. It has a square-shaft lead that is followed by a series of round-shaft extensions.

Sizes

Typical sizes for combo helical piles are: 1.5”/2.875”, 1.75”/3.5”, 2.25”/4.5”.

Advantages

Combo helical piles offer the “best of both worlds” when it comes to installation and performance. Here are some of their advantages:

• Great penetrating characteristics of square-shaft piles
• Suitable for very dense or rocky soil conditions
• Large-diameter round shaft extension
• Bucking resistance
• Able to support high lateral loads

Disadvantages

Now you might be wondering, “Why wouldn’t I just always use a combo pile?” Well, it’s not always necessary and it’s always more expensive. The extra material costs make combo piles less affordable, so it’s best to only use them when they’re absolutely needed.

Suggested Applications

Combo helical piles are most often used in compression applications. This is when layers of hard soil are buried deep under softer surface soil. Think of environments like high water tables, grout-restricted sites, etc.

For Helical Pile Design & Installation Done Right, Contact Elite Helical.

To get the most out of your helical pile installation, you need to make sure you’re working with the helical pile design that best suits your application’s needs.

Need help making the right choice? Contact our experts at Elite Helical. We’ll walk you through various options, then help you install a foundational system that will last for years.

You may have heard that helical piles are some of the strongest, most durable foundational solutions on the market. But how long do they actually last? Find out below. 

How Long Do Helical Piles Last? The Breakdown

Generally speaking, helical piles can last 100 years or more. Most contractors estimate a lifespan of around 150 years, but some helical piles have even lasted 300+ years. 

Needless to say, these are some of the longest-lasting tools in the industry. Their great longevity makes a case for them being the most cost-effective and environmentally friendly solutions on the market as well. With fewer repairs and replacements necessary over the years, you won’t have to worry about putting too much time and money in besides the upfront installation investment. 

Factors That Influence Helical Pile Lifespan

Not all helical piles last the same amount of time. Some fail faster than others, and some live to see their 350th “birthday.” How? There are a number of factors that affect helical pile longevity — most of which are environmental and have nothing to do with the helical pile itself. 

Helical Pile Material

Most helical piles are composed of rust-resistant galvanized steel. This is a strong, durable material that will help them perform for centuries. However, if you were to use a different type of material, that performance may suffer or improve even more. 

Load-Bearing Capacity Calculation

Some great benefits of helical piles is that they offer instant load-bearing capacities and that they can support structures of all shapes, sizes, and weights. If you design and space accordingly, they can accommodate hundreds of tons or more. 

However, if you were to get your load-bearing capacity calculations wrong and mistakenly apply too high of a load to the pile system, its endurance could falter. 

Soil Conditions

Helical piles may not last as long in areas with poor, volatile soil conditions. Anything highly acidic, rocky, or eroding could expose the piles to more wear and tear. 

On the flipside, helical piles placed in environments with very stable soil conditions could last much longer than the typical 150-year lifespan. 

Location

Similarly, various regions lend themselves to significant ground movement — which could definitely affect the lifespan of your helical piles. Think of locations like coastal areas, mountainous areas, and places with fault lines. The soil movement in these environments could break your helical piles down much faster than stable soil would.

Helical Pile Life Expectancy vs. Other Foundational Solutions

Let’s take a look at how helical pile life expectancy stacks up against other foundational solutions. You might be shocked! 

Here’s a chart with estimates for how long each choice can last. Please keep in mind that these are estimates and do not take the influencing factors listed above into account. 

Foundation Material	Estimated Lifespan
Helical Piles	150 years
Stone	100 years
Slab Concrete	80 years
ICF Blocks	75 years
Wood	25 years

Ready to Get Your Helical Pile Project Started? Contact Us.

For safer, sounder solutions you can only trust the best. Elite Helical is your top choice for turnkey helical pile solutions that will last a lifetime — or longer! Get in touch with our experts to learn more about how we can support your next project.

The helical pile world can be technical and confusing. With decades of experience in the industry, we’re happy to help simplify it a bit.

If helical piles are a new concept for you or you’re looking for more information before you can fully decide if they’re the right solution for you, you’re in the right place. This is a glossary-style blog post full of all the most important helical pile terms you should know.

15 Key Helical Pile Terms You Need to Know

Every day, more and more information is published about helical piles and how they function to make great foundations. But it can be difficult to fully grasp their capabilities if you don’t understand some of the technical terminology.

Here are 15 of those terms related to helical piles, helical pile design, and helical pile installation — broken down into clear definitions by our experts.

1. Helical Pile

A helical pile is a segment that makes up a larger, deeper foundational system. It consists of a central shaft, and at least one helical plate welded onto it. The plate’s axis is positioned parallel to the shaft’s length — making it look similar to a screw.

Helical piles are also commonly referred to as: helical piers, helical anchors, helical foundations, screw piles, and screw anchors.

2. Helical Plate

A helical plate is one component of a helical pile. It’s a helix-shaped blade that’s welded onto the central shaft of a helical pile section. When embedded into soil, the helical plate helps to support compressive and tensile loads, and they’re spaced in a way that minimizes soil disturbance during installation.

Helical plates are also commonly referred to as helical blades and helical bearing plates.

3. Lead Section

A lead section is the first section of a helical pile. It’s the first to make contact with soil and always has at least one helical plate.

Lead sections can vary in length depending on project needs but are usually between 5-20 feet.

4. Helical Extension

A helical extension is a square bar or round shaft section that connects onto the helical lead section. It’s needed to form a continuous length of steel so the pile can reach its intended depth.

Helical extensions are most often smooth sections, but can also have helical plates welded onto them in certain situations — usually when you’re dealing with very soft soil.

5. Pitch

Pitch is the distance between one helical plate and another along the central shaft. It’s critical that the pitch is uniform to ensure minimal soil disturbance during installation and optimal performance post-installation.

6. Torque

Torque is the force applied to a helical pile (usually by a gear motor) that causes the pile to rotate and embed itself into the soil. It’s an important measurement to calculate before the installation process.

7. Tensile Load

Tensile load is the force pulling at a helical pile, often causing the pile to lengthen or pull out. Examples of forces that produce tension loads include wind, soil, water buoyancy, frost, and earthquakes.

Tensile load is also commonly referred to as tension load.

8. Compression

Compression is the force pushing on a helical pile, often causing the pile to shorten or settle deeper into the soil. It’s the opposite of tensile load.

9. Lateral Load

Lateral load is the force that pushes or pulls on a helical pile in a direction that’s perpendicular to the longitudinal axis of the pile.

10. Down Drag

Down drag is a circumstance where soft soils around a helical pile consolidate and pull downward, causing the pile to settle deeper into the ground. Down drag can occur due to the weight of soil, changes in groundwater or other additional loads put on the ground surface.

11. Corrosion

Corrosion is any force of nature that corrodes the helical pile metal and weakens its performance over time. Although it’s an extremely slow process, it is an important factor to consider when looking at your project’s soil conditions and environment.

12. Soil Resistivity Rating

A soil resistivity rating determines the rate at which a helical pile will corrode. It considers things like soil conditions, environmental conditions, the thickness of steel, and any corrosion protection measures that have been taken.

13. Slide

A slide is a device that attaches to the boom of an excavator. It’s used to stabilize and control the forward and backward movements of a torque motor during the helical pile installation process.

14. KIP

Acronym for Kilo-pounds. Helical pile engineers often specify in KIPS while designing helical piles and referring to the loads they can support. 1 KIP = 1,000 pounds.

15. OSHA

Acronym for the Occupational Safety and Health Administration. OSHA has established many health and safety regulations that apply to helical pile installation — the most prominent being OSHA 1926.6603.

Elite Helical is dedicated to ensuring safe helical pile installation practices, so we maintain strict adherence to OSHA standards.

Do You Have a Helical Pile Project in Mind? Contact Us!

The helical piling industry can get technical. At Elite Helical, we’re here to make it easier on you by providing safe, high-quality solutions, and keeping you informed every step of the way. If you have questions on helical piles, the installation process, or if we’re the right choice for you, contact us today.

The construction industry has a large footprint and heavy footfall when it comes to environmental impact. But more than ever, reducing that impact is a necessary consideration for industrial and commercial construction for social, ecological, and economic reasons. This reckoning comes with an exploration of alternatives to traditional methods; in the foundations space, this means helical piles.

Helical piles offer some distinct environmental benefits over conventional foundations, including recyclable materials with a lower emissions profile, reduced soil displacement, and increased durability—all of which are also distinct financial benefits, and reflected in the relatively low cost of helical pile foundations. There are also some exciting applications for helical pile foundations in renewable energy infrastructure.

Helical Piles Are Made from Recyclable Materials

Helical piles are generally made of steel. The current process for manufacturing steel does emit a significant amount of carbon; however, steel is nearly infinitely recyclable—steel that is no longer in use is melted down to create new steel products. When a building or structure using a helical pile foundation is decommissioned, the helical piles can be recycled. In some instances, where the helical piles are still in serviceable condition, they can even be reused, significantly lowering the environmental impact per use as well as the cost of the project.

It is also the case that steel is an alloy of iron and carbon, two naturally-occurring substances. While untreated steel will suffer from corrosion, helical piles are treated for corrosion resistance. Variants of steel such as stainless steel are wholly corrosion resistant and are neutral and inert in the environment.

This is not the case for concrete foundations. Concrete manufacture is responsible for over 8% of annual global carbon emissions, and carbon emission is an inherent byproduct of the chemical reactions that form cement. And its environmental effect doesn’t stop with manufacturing: It is carbon-intensive to transport, and concrete leaches chemicals into surrounding soil and water when it is poured and when it comes into contact with water and acidic substances.

Helical Piles Reduce Soil Displacement

Helical pile foundations require significantly less soil displacement than conventional foundations. This is because rather than digging out a flat surface onto which to pour a concrete foundation, helical piles are screwed into the soil itself.

Heavy, resource-intensive equipment is used to excavate and level the soil for poured foundations. Then the soil that is displaced during the construction of structures is used as fill or removed from the site, increasing carbon emissions due to the transport of tons of heavy soil.

This soil displacement can have knock-on effects on the landscape, such as risking erosion. Any time soil is displaced, the potential for rain and wind erosion increases. It’s also the case, and particularly so for industrial applications, that there may be unknown contaminants in the sediments being exposed by excavation. Contaminated soil that is exposed can pose risks to human and environmental health.

Increased Durability Improves Sustainability

Deep helical pile foundations are extremely durable. In fact, helical piles can have a lifespan of over 150 years in normal soil conditions. Poured concrete foundations are generally considered to have a life expectancy topping out at about 100 years.

While durability isn’t synonymous with sustainability, the longevity of helical pile foundations does reduce consumption. A stronger, more durable foundation that lasts longer means that it uses less resources over its lifetime since it does not require repair, fortification, or replacement as soon as less durable foundation materials.

Green Tech Applications for Helical Piles

While not an argument for the environmental friendliness of helical piles themselves, it is notable that some key green technologies make use of helical pile foundations. Helical piles are used for (non-roof mounted) solar panel foundations, ensuring that wind and weather don’t affect the stability of the panels.

Helical piles are also used in some wind turbine applications. As with solar panels, wind turbines are top-heavy, requiring deep foundations to ensure their stability. Battery installations, often in conjunction with solar panels, also make use of helical pile foundations, necessary because of their weight.

For applications like solar panels, helical pile foundations have an additional environmental benefit in that they take up less surface area on the ground. This is beneficial because it means less of the surface is impermeable. This is a boon for plant life, which grows in soil, not concrete, but also protects the soil against erosion from runoff. Impermeable surfaces like concrete prevent stormwater from filtering back into the groundwater naturally, which can cause drainage and infrastructure issues and contribute to flooding.

Learn More About Your Helical Piling Options

If you’re looking to invest in a more eco-friendly foundation solution, helical piles are your go-to. With unmatched durability, minimal installation vibration, and recyclable materials, helical piles not only outperform poured foundations, but they’re also more sustainable. Contact our team of helical piles experts at Elite Helical to learn more.

Before helical piles are installed, there are a few design considerations you need to make to ensure they’ll effectively support the intended structure. Without taking into account the size and shape of the piles, the type of soil, the pile capacity, and other such factors, your design may risk failure. Keep reading for six aspects of helical pile foundation design to consider when planning your industrial construction project.

1. Load-Bearing Capacity

The load-bearing capacity of the helical piles to be used for your project is the first and most important consideration for helical pile foundation design. You need to know whether the piles will be able to bear the load of the intended structure, which informs other aspects of design, like the shaft size, number of piles, spacing, and depth.

There are three primary methods to determine helical pile capacity:

• Direct capacity measurement
• Torque correlation
• Bearing capacity in the soil

At least two of these methods should be used in conjunction when calculating load capacity for helical pile design to ensure accuracy and safety.

2. Shaft Size and Type

There are three main types of helical piles: round, square, and combination. These different shapes are suited to different conditions. The hardness or weakness (looseness) of the soil can inform the shaft type to be used. Some soils may be too hard to use round piles, and square or combination shafts may be required. Conversely, round shafts are better suited to loose, weak soils due to the compressive loads they’ll experience in that soil condition.

3. Spacing of Helical Piles

The spacing of helical piles depends both on the number of piles you need to safely bear the load of the structure and the size of the helical plate. The helical plate (also referred to as the helical bearing plate or helix) is one pitch (complete revolution around the pile) of the screw thread. The larger the helical plate, the larger the minimum spacing required.

Since the helices do not extend the entire length of the helical pile, maintaining the necessary minimum spacing is necessary not at ground level, but at bearing level, where the helices are in their final installed position. For structures that require additional load bearing capacity, helical piles can be installed at angles that ensure minimum spacing at bearing level while reducing spacing at ground level.

4. Depth of Helical Pile Installation

Like other deep foundations, helical piles are generally installed at greater than 3 meters below the ground’s surface. The depth should be at least 6 times greater than the diameter of the biggest helix, as measured from the top of the pile to the uppermost helical plate.

Increased depth = increased torque = greater load bearing capacity.

For applications where the soil doesn’t provide enough friction to support the load of the structure at shallower depths, longer, deeper helical piles may be required. Challenging landscapes, such as offshore construction, may require deeper foundations, to support the weight of the installation in water and sand.

5. Soil Type

It’s crucial to consider the soil type when designing a helical pile foundation, as the strength of the load bearing capacity of the piles depends on the torque applied to the piles due to resistance from the soil. When considering soil type for helical pile installation, soil is classified into two general types: fine-grained and granular. Fine-grained soils have a diameter of less than 0.075mm; granular soils have a diameter of greater than or equal to 0.075mm.

Type of soil	Classification
Clay	Fine-grained
Silt	Fine-grained
Gravel	Granular
Sand	Granular

6. Location and Environment

In addition to the soil present at the construction location, there are other environmental factors to consider that are location specific. Given that helical piles are driven deep into the soil, it’s also critical to know that there are no obstructions where your piles are to be sunk.

This entails more than just calling Miss Dig—you need to ensure that there are no underground utilities, impenetrable rock, caves or caverns, underground water sources, pockets of natural gas or oil, or even just the ruins of old structures or debris. Anything that could impede the screwing in of a helical pile or reduce its torque could compromise the integrity of the foundation.

Helical pile foundations are revolutionizing foundation design with distinct advantages over poured foundations in difficult landscapes and heavy industrial applications. But it’s important to consider the above factors in your helical pile design. If you need help with helical pile design for your construction project, contact a trusted helical pile installer.

Interested in using helical piles to support your next construction project? You’re going to need a solid design before getting started. As your turnkey helical pile contractor, Elite Helical can help with all steps of the process — from design to supply to installation. Contact us online today.