Due to Canada's unique geography, landscape, and location, we enjoy what you might call a "challenging" climate here.

We can go from wearing parkas to swimming at the cottage in just a few weeks. Which also means we can go from swimming at the cottage back to wearing parkas in just a few weeks. We'll broil in 30 degree heat in July, then freeze in -40 blizzards by January.

That climate isn't just hard on the people, either. Canada's conditions are even tougher on foundations, especially typical solutions like poured concrete.

As a result, helical piles have emerged as a preferred foundation among many telecom engineers and contractors. They're using helical piles to build communications towers days, even weeks, faster than concrete. Often, they're also doing it more economically than concrete.

As this foundation appears under more projects in more places, more communications tower contractors and engineers are wondering if helical piles might be a suitable foundation solution for their projects.

In this post you'll learn:

● Why Canada's climate is so dangerous for communications towers
● What role soil and climate plays in your foundation performance
● The deep frost line in Canada and what it means for your tower project
● How helical piles work for communications tower foundations
● Why more companies are using helical pile foundations for their towers

Why Canada's Climate is Bad for Communication Tower Foundations

As helical foundation contractors, we think about the soil every day. It's a varied blend of organic matter, minerals, and other materials. Across much of Central Canada, the soil is relatively slowly draining and mixed with dense clay layers.

The nature of our unique blend of soil, known as expansive soil, makes it prone to movement as the ground freezes and thaws.

In winter, the moisture in the soil freezes and causes it to swell. This swelling puts enormous pressure on deep foundations. When a deep foundation can't hold against the pressure of the frost, it ends up being pushed (or heaved) upwards.

When spring comes, the frozen soil melts and leads to a shrinking action. All the pressure is released and the ground settles back down, possibly even settle lower than before the winter season. This is bad news for any foundations that have been heaved. As the ground shrinks and settles, the foundation will settle along with it.

Combine that extreme climate and a deep frost line with our expansive soil and you end up with significant swell and shrink movement as the soil freezes and thaws.

This frozen and saturated ground will experience significant swell/shrink action as the spring thaw sets in and the ice crystals turn back into liquid water

To make things worse, lightly loaded structures (like communications towers) can be especially prone to the effects of these forces. They don't have the weight to exert enough downward force to overcome the enormous uplift strength of swelling forces caused by frost.

Concrete Foundations for Communications Towers

Traditionally, engineers have overcome the frost problem by pouring dense and heavy concrete foundations for communications towers. They, essentially, use sheer bulk to overcome frost heave and provide a sturdy foundation. Reliable enough and cheap enough to build, they've become a common choice due mostly to the familiarity and ubiquity of concrete.

Concrete has been the commonly-accepted foundation for communication towers, but it comes with its downsides

The idea behind a concrete communications tower foundation is pretty straightforward. Pour lots of heavy concrete in a big wide hole, reinforce with rebar, put the tower on top.
(I'm simplifying things, but you get the jist)
For a long time this has worked "well enough" and doesn't take a huge amount of technical skill to install. Plenty of contractors can dig a hole and pour concrete. So, here we are, with concrete foundations being a sort of de-facto standard for tower foundations.
Does that mean concrete is the best choice?
It may enjoy widespread use but it some downsides:
● Excavation leaves tailings to deal with, damage to leased land● Concrete can be expensive and difficult to source in rural area● Climate and soil conditions are harsh on concrete● Removing concrete foundation during site remediation can be expensive● Increasingly harsh climate could damage concrete● Concrete foundations are prone to sinking
If you're building a tower in a well-serviced, easy-access site, some of these downsides might not be a problem for you.
What if you're building a tower five hours north of civilization? With companies putting towers in ever-more rural regions in Canada, contractors and engineers are increasingly running into frustrating challenges with concrete. Whether it's too expensive, too difficult to source, or leaves too much impact on the land.
The need to build towers in remote and harsh locations isn't going away, and is indeed only growing. Time to look at the foundation solution that has engineers and contractors in the tower industry buzzing.

Helical Pile Foundations for Communications Towers

At first glance, the design of a helical pile might seem almost too simple to believe. There's nothing overtly impressive about them. Just one (or more) helix-shaped plates welded to a round or square steel shaft. It certainly doesn't look like a deep foundation that can support upwards of a million pounds.

While a helical pile may not look like a high-capacity foundation at first, a deeper inspection reveals the genius design that make it significantly more efficient than concrete

Yet despite its looks, helical piles absolutely can and do support heavy structures with ease. And they do (generally) faster and easier than other solutions. There's no magic or mystery, just really good design.

To understand how helical piles work and why they're an outstanding choice for tower foundations, let's take a closer look at the pile's design and components.

Pile Shaft

The pile shaft makes up the "body" of the helical pile, and is what all other components attach to. Typically, the pile shaft will be constructed of a hollow round pipe or square shaft, or a solid square bar. Which type of pile shaft is used depends on the structure, loads, soil conditions, and more.

Like everything else on a helical pile, the shaft is manufactured from tough steel. The wall thickness will vary based on factors like structural forces, soil conditions, and intended design life. We can add additional thickness to a pile to defend against corrosive soil and ensure it meets the service life.

While it's tempting to think the pile shaft plays a big role in determining the load capacity of the pile, that's not entirely true. The pile shaft does provide strength to the helical pile, but its most vital role is to transfer loads down to the helix plate. This is why the shaft is relatively narrow compared to the helix plate.

There's no need, in most cases, to have a large diameter pile shaft. Many communications tower foundations can use piles with a diameter of less than 12". We can value-engineer helical piles to ensure you're not paying for more foundation than you need.

Lead Section

The lead section is the first part of a helical pile to be installed. It's usually 5 or 10 feet long and includes at least one helix plate. At the end is the pilot point, cut on an angle to make installation easier.

You may also see other types of pilot points like drill bits or auger tips. These are used in situations like very dense soils that need some extra muscle to install into. For the majority of jobsites, we don't have to worry about using special pilot points.

Extension Section

A helical pile in Canada may need to go as deep as 100 feet or more into the soil in order to reach firm stratum. Since it would be impractical to transport a 100 foot helical pile, they're manufactured in (typically) 10, 15, or 20 foot sections. To reach the required depth, we use extensions to add length to the pile.

Once a section of helical pile is turned deep enough into the soil, the install is paused momentarily so an additional extension can be attached. A coupler is used to securely attach these extensions together. We can increase the length of the pile until the appropriate depth and torque is reached for each specific pile location.

Here's an example:

Let's say that, during the design phase, your geotechnical report indicates good soil at about 35 feet. Install day comes and your helical pile contractors discovers that, for two of the piles, the soil at 35 feet is still weak.

Instead of having to re-design the foundation, our crew can add extensions to the piles until they reach supportive soil. What could be a complicated and expensive change order is nothing more than a brief hiccup that's resolved in record time when choosing helical piles over traditional piles.

Couplers

Pile extensions need to be coupled together in order for the installer to reach the required depth. This is the job of the coupler They come in a variety of designs and can be secured with threads, pins, bolts, or welds. Regardless of which specific method is used to attach them, they're all designed to firmly attached the sections of helical pile together and withstand structural loads.

Helix Plate

A helix plate (pl. helices) is made from a steel plate that's (typically) stamped into a spiral shape and welded to the pile shaft.

It's the helix plate that really makes a helical pile special.

It follows a defined pitch, regardless of its diameter. This pitch is identical for all the helices on a pile, but the exact geometry varies depending on the application. Helices are arranged to ensure they follow the same track through the soil and minimize disturbance.

Depending on the soils profile the helices will be spaced far enough apart on the pile shaft so they don't influence each-other. Or, they'll be optimally spaced to engage cylindrical sheer which amplifies the capacity of helical piles.

Helix plates can support an enormous amount of force in both compression and tension. They function on a straightforward concept that's been studied since helical piles were first invented almost 200 years ago.

As the helices turn into denser soil, the soil exerts increasing force on the helices. We can read this force during installation in terms of the torque we have to exert on the pile to get it to turn. If it takes more torque to turn the pile, that means the soil is exerting more force on the helices. Helical pile contractors can utilize torque to predict the soil capacity and thus pile capacity.

This force exerted by the soil on the helices gives a helical pile its load capacity. The pile shaft transfers structural loads from the surface down to the firmly-anchored helices.

Pile Cap

After the helical piles are turned into the ground, they still need to become a cohesive foundation. This is achieved with a pile cap. A pile cap adapts the top of a helical pile to whatever structure is being supported.

This helical solution ties several helical piles together to provide axial and lateral support to a monopole communications tower

Pile caps can be as simple as a sleeve and steel bearing plate, or they can be beautifully designed custom adapters.

A quality pile cap makes attaching a communications tower to the helical foundation a breeze and can save a bundle of time on-site. For communications towers, pile caps might tie together pile groupings with a single plate, multiple plates or a custom tower grillage.

Benefits of Helical Piles for Communications Towers

Faster and easier to install (and uninstall)

Helical piles are ready for loading immediately after install, meaning your foundation could be installed and ready to use in just a few hours. They're easier to install than concrete, too, which makes them a breeze to coordinate.

Equally important is that helical piles are easy to uninstall.

Towers are often built on leased land, which means you'll have to fully remediate the site when the lease expires and you decommission the structure. If you pour a big concrete pad, you're looking at extensive excavation work to remove the foundation and new fill to remediate.

Helical piles are easy to install and they're easy to remove, making future site remediation significantly less costly in terms of money and time

Helical piles simply "unscrew" from the ground, leaving zero trace they were ever there. This makes restoring the site dramatically easier and more affordable compared to concrete.

Often cheaper than concrete foundations

Helical piles are generally less costly than concrete foundations for communications towers, particularly in remote or rural locations in Manitoba. Concrete demands a large amount of materials, equipment, and people to install. Hauling all of this to a rural jobsite can be an expensive proposition.

By comparison, a helical pile install only takes a few crew and some simple equipment.

Skidsteers or mini excavators can be used for some sites, while particularly challenging soils may need the help of a larger excavator. In either case, this equipment is easily transported by a truck and trailer. The piles themselves are lighter than concrete and take up much less space, so they're often transported on the same trailer as the equipment.

Some helical pile communication tower foundations may only require a lightweight mini-excavator to install, such as this project in Canada

One expense often overlooked is the site preparation work required prior to construction so heavy equipment can access the site. Helical pile equipment and mobilization is much more nimble and light which means less site preparation is required, and often no ground improvement or matting is required.

At VersaPile we also send along a welding support truck so our crews can attach pile caps, grillages, or other structures, to your piles.

The result is fewer vehicles, people, and equipment, need to be on your site. This reduces your mobilization costs, minimizes site disturbance, and slashes your time-to-build.

More environmentally-friendly than concrete

Concrete is, no secret, very bad for the environment. It's takes enormous amounts of CO2 emissions to produce it, a huge effort to remove it, and you need a lot more of it to support your tower. In fact, it could take up to 900% more raw material to install a concrete foundation compared to a helical pile solution.

Helical piles are manufactured from steel. While steel has environmental impacts all its own, the hugely efficient nature of helical piles means you could decrease your per-pile emissions by as much as 500% (or more) with by using a helical foundation.

Uses dramatically less raw material

It takes an enormous amount of raw material to install a poured concrete foundation compared to a helical pile solution. Like I mentioned earlier in the article, the unique design of helical piles means they can support an enormous amount of weight relative to their size.

Concrete, on the other hand, uses large amounts of raw material in order to provide support. Not only does this create a more significant impact on the environment, it adds weight (and hassle) that you need to transport to your jobsite. Considering the fact that communication towers are often built in remote locations, every kilogram of weight you have to transport adds to your cost.

No Soil Disturbance

Helical piles don't require excavation to install, so they don't disturb the soil like other foundations will. Poured concrete, conversely, requires extensive excavation and soil displacement. This has significant environmental considerations, but also impacts the cost of your project as it's up to you to deal with the tailings.

The helix plate on a helical pile ensures the pile advances smoothly through the soil without significantly displacing material. What that means for your project is no tailings to deal with, no environmentally-costly excavation, no disruption to the local ecology.

Easy to uninstall

Removing a helical pile is the reverse of installing it: simply turn it out of the ground using a hydraulic helical drive. The helical design helps it reverse from the ground without creating any disturbance, leaving no impact to the soil and making site remediation easy.

This feature makes helical piles an ideal solution for temporary structures or ones built in ecologically-sensitive areas that need to be completely remediated at the end of their service life.

Recyclable

The steel from a salvaged helical pile can be 100% recycled into new products like car frames, appliances, or even another helical pile. In fact, more than 70% of the steel produced in North America is done so using recycled steel which drastically lowers production emissions.

While some components of concrete can be repurposed, it isn't a truly recyclable materiel like steel is.

Supports axial and lateral loads in compression and tension

Communications towers are subject to an intense climate on the open prairies. Straight-line winds exert huge amounts of lateral force on the tower. Winter slams it with savage blizzards and heavy ice buildup. Even the soil is constantly shifting and moving.

When the forces are particularly high helical piles shine bright in overcoming massive bending moments, lateral reactions as well as axial and tension loads when installed in battered pile groupings. By installing helical piles on opposing batters we are able to group multiple piles tightly but where the helices are spaced far enough apart that the piles are undermining one another.

Installing piles on a batter, which is not possible with many traditional pile alternatives, can be a huge advantage in satisfying large lateral and bending moments.

VersaPile crews installing helical piles on an angle (battered piles) to increase lateral load support for a transmission line project

The result is that a tower has to withstand complex loads than can change very quickly. Not only will the foundation need to hold axial (vertical) and lateral (horizontal) loads, but it needs to do it under compression (pushing) and tension (pulling) energy.

A helical pile's design makes it ideal for resisting these dynamic conditions. Like you saw when we studied their design, a helix plate anchored in firm soil excels at resisting compression and tension forces. And no matter what the axial and lateral load capacity requirements, an engineer can design a pile configuration to meet them.

Conclusion

Communications infrastructure in rural Manitoba has been a pain-point for residents in these communities for decades in some cases. It's fantastic to see companies making the investment to improve the services in these communities and help reliably connect them to the world.

Helical piles are being used by engineers and contractors to get more out of their investment in rural infrastructure. By saving time and money on the cost of a concrete foundation they can build better towers, in less time, for less money. That's a good deal for everyone.

Why not find out if helical piles can help your communications tower project save time, money, and headaches. Scroll down to have a friendly no-obligation chat with one of our communications tower foundation experts. They'll learn about your project, do an honest assessment, and help uncover the unique benefits a helical pile foundation could have for you.