John Lisle | Common Helical Pier Questions

Helical pier foundations can fail. That might seem like a strange statement coming from a guy who co-founded a helical pier installation company, but it's the truth. And when a helical pier foundation does fail, you can bet detractors will jump on LinkedIn to smugly claim that helical piers are a "flawed technology".

Here's the thing: just because a helical pier foundation can fail (and sometimes does), doesn't mean they're a flawed foundation solution.

There's always a cause of the failure, some deficiency (usually human-related) that sets the process in motion. A properly installed helical pier foundation will not fail, unless exposed to forces far beyond the design intent.

But, I don't expect you to just believe me when I tell you that the social media detractors are simply full of hot air. Or when I tell you that helical piers are not a flawed technology and are every bit as safe (often even more so) than other solutions. Because unlike the detractors, I'm going to use facts to prove to you that helical piers only fail as a direct result of someone screwing up.

Not because the technology is flawed.

Let's take a look at how helical pier foundations fail, why they fail, and what you can do to avoid it.

Are Helical Piers a Bad Deep Foundation Solution?

Did you know there were over 35,000 traffic-accident deaths in the United States in 2019? It's a dangerous gamble, hopping in your vehicle and hitting the road. Especially when you consider most of us don't think twice about eating, glancing at our phone, or fiddling with the radio, even though we're hurtling down the road in a steel cage doing 70mph.
Still, despite the danger, most of us don't think twice about the risks of driving. We simply do it. 
Few people would stop driving just because their neighbor had an accident. In fact, I'll bet some of you reading this have been in a car accident and still drive. 

Driving a vehicle is one of the most dangerous things we do every single day without even thinking about it

See, we understand that a car accident isn't the fault of the car itself. It's the fault of the driver (or a mechanic, manufacturer, etc). The car itself doesn't have anything to do with the accident, instead the accident is the result of human errors or complacency.

In the same way, just because some helical pier foundations have failed doesn't mean the technology itself is flawed. So, why are some folks so eager to dismiss helical pier foundations just because there's some cases where they've failed? Especially when, as I'll show you, the failures are not the fault of the helical piers?

I'm not entirely sure of the exact reasons why people have a deep-set dislike for helical piers, but I think a big part of it is a misunderstanding of the technology. When they see a failed helical pier on LinkedIn, it's easier to leave a comment that digs on helical piers instead of looking for the real story.

I can't cover every failure method of a helical pier foundation in this one article. Instead, I'm taking the three most likely methods of failure and showing you their true cause.

Before we do that, though, I want to make a case for why you should trust helical pier foundation technology.

Why Should You Trust Helical Pier Foundation Technology?

Helical piers have gained an undeserved reputation as some odd new "unproven" foundation that hasn't been around long enough for us to trust. Critics have perpetrated this myth, I believe, to make it seem like helical piers are a scary unproven technology that doesn't belong in "conventional" construction.
Let me tell you something that engineers absolutely hate: unproven things. 
Structural engineers aren't (usually) interested in bleeding-edge never-before-seen solutions. They want to implement solutions that have clear data that supports their use and a track record of success. 
Most engineers don't want to win brownie points by finding the most niche or "out there" technology. It makes sense, too, when you realize that many engineers in the U.S. are afraid of getting sued. 
Helical piers have been used, studied, and improved, for almost 200 years. From small-scale residential to epic installations for ultra high-capacity oil & gas projects, they've proven themselves as efficient and economical foundations across the globe. 

Helical piers helped revolutionize travel on oceans, inlets, and waterways, as they allowed navigation lights to be built in previously-inaccessible areas

If helical piers were as "unproven" as the haters claim, I can absolutely promise you that engineers would have never decided to use over 228,000 helical piers to support an epic 3,300 acre solar farm in Alberta, Canada. No company would ever make that kind of investment in a key component of a project (the foundation) without having absolute confidence in that technology.
The International Code Council includes helical piers in their AC358 "Acceptance Criteria for Helical Pile Systems and Devices". 
Helical piers are studied by major universities in the United States, Canada, Europe, India, and more. 
To say helical piers aren't a well-known, well-studied, well-understood foundation, is to clap your hands over your eyes and ignore the clear data available to us. 
Yes, you can trust helical pier foundation technology.

How Do Helical Piers (Typically) Fail?

Alright, if helical pier technology is so "proven" and "tested", why do some helical pier foundations still fail?
This is an important question to answer, because at the root of every foundation failure (helical pier or otherwise) there's important lessons we can learn. 
Covering all the possible failure modes of a helical pier foundation would be quite a challenge, because if you look close enough no two failures are ever truly "the same".
But, most helical pier foundation failures tend to take on one of three primary forms:● Bending/breaking● Sinking/settlement● Lateral shifting/settlement
We'll take a look at each of those types of failure, then I'll uncover what you can do to avoid foundation failure.

Bending and/or complete breaking of the helical pier

If you've seen photos of an excavated helical pier foundation with bent or broken piles, it can look pretty dramatic. A complete failure of a helical pier (either by bending or breaking) is a serious incident and thankfully not very common.

When we're talking about helical piers bending or breaking, there's a few different places to look for answers. And the best place to start is with the design of the foundation itself. 
Many factors are considered by an engineer when designing a helical foundation. Structural loads, soil conditions, climate, load types, these are just a handful of factors that influence a helical foundation's design.

Some of the factors we consider when designing a helical pier foundation

Designing a helical pier foundation takes skill, training, experience, and science. It also demands that the designer have an understanding of the soil and how it interacts with deep foundations.
Let's say you build two identical structures on two identical helical pier foundations... 
"Structure One" is built on firm, well drained, non-expansive soil, in a mild southern climate. 
"Structure Two" is built on soft, poorly-drained, expansive soil, in a harsh northern climate. 

Fast-forward 10, 15, or 20 years. 
Structure One is standing firm without any foundation issues. 
Structure Two, however, has experienced failure of the helical piers as they were unable to resist ground movement and ultimately bent or broke entirely. 
Why is this? How could two identical structures on two identical foundations end up with different outcomes?  
You've probably guessed the answer, but the reason is that Structure One and Structure Two shouldn't have identical helical pier foundations!
A helical pier installed into good soil with mild conditions will behave very differently compared to a helical pier in difficult soil with harsh conditions. That's why our designers work to understand the soil and climate conditions at your jobsite. Those conditions can have a big impact on how your foundation is designed and which helical piers are used. 
In the case of our two fictional structures, here's the solution...
Structure Two, facing harsh soil and climate, should have used a beefier foundation design compared to Structure One. Our hypothetical helical contractor should have recognized the difficult conditions for Two and revised the foundation accordingly. 
If a helical contractor doesn't account for the unique properties of the structure, site, and soil, the result is a foundation that won't perform how it should. 
Another cause of helical piles bending or breaking is poor manufacturing practices. You usually see this failure when a smaller helical pier contractor tries to save a few bucks by sourcing cheap piers or even tries to manufacture piers themselves. They'll source cheap materials, do sloppy welding, and completely ignore any sort of quality control.
Thankfully, this behavior is easy to avoid as long as you work with quality contractors who can show you engineering papers for their helical piers. Good contractors love good engineering and will be happy to share it with you.

Sinking or settlement of the helical pier

One of the benefits of helical piers is that they resist sinking and settlement better than other foundation solutions. They're able to do this because of the unique design of the helix plates that help give them enormous strength. These wide plates anchor in firm layers of soil and help the pier resist compression and tension forces.

Helix plates are designed to smoothly turn into the soil and anchor in firm & supportive layers of soil

Unlike other typical deep foundations, the design of a helical pier allows us to have a wide surface area that resists movement underground without requiring excavation or hydraulic hammers. 
This unique property is why helical piers are great in loose or saturated soils - the force of the soil pressing on the helix plates prevents them from moving.
When a helical pier sinks, it's typically the fault of:● An inadequate installation● Not studying the geotechnical report● Failure to test piers after installation
A helical pier must be installed to a specified depth and torque specification (determined during the design process) in order to achieve the desired load capacity. Load testing of the foundation might even be required for certain projects. If the piers aren't installed to proper specification, the foundation can't performed as it was designed.

Sinking could also occur in other circumstances, like if a helical pier was anchored in a layer of firm soil that rested on top of a layer of loose or shifting soil. In this scenario, the pier could "punch through" the firm layer because there's not enough support beneath the helix plates. However, this type of failure can be avoided with good geotechnical reports and load testing piers of concern.

Helical piers shifting laterally

The final failure we're looking at is a lateral failure. In this failure, the pier is essentially pushed over in the soil and fails. Unsurprisingly, this one comes down to good old-fashioned human error too.

When we design a helical foundation, we consider all the types of load the structure could experience. One of these types of load is called a lateral load, which is force exerted in a horizontal direction on the structure. Lateral loads can come from wind, ground movement, freeze/thaw cycles, or even seismic activity.

Some examples of lateral forces that can act on a helical pier foundation

Thankfully, helical foundation engineers can design a pier configuration that defends against lateral loads. Usually, this involves installing additional helical piers at an angle to provide increased support from lateral movement. Often, for projects that require lots of lateral support, helical piers will actually be the preferred foundation because of their performance.

We see lateral failures on helical piers when either:● Foundation design was insufficient for the real-world lateral loads● Helical pier contractor failed to follow design specs or install piers correctly

In both cases, once again, helical pier technology is not to blame. With a good foundation design, and a helical contractor who follows it, lateral loads should be no problem whatsoever. Want proof? Check out this helical foundation for a massive slug catcher with off-the-charts lateral loads.

How Can You Prevent Foundation Failure?

Okay, enough with the scary "here's how foundations can fail" talk. Even though foundations can fail, it doesn't mean they will fail. 
You have a huge amount of control over the performance of your foundation. Even if you aren't a foundation engineer.
Did you notice all the failures we looked at today had something in common? They were all the result of flawed thinking and actions, not of flawed technology. 
Knowing this, how can you make sure the foundation for your project is safe, efficient, and long-lasting? 
It really does come down to one key step: finding an expert foundation contractor.
Working with a professional, experienced, and quality foundation contractor is the best way to ensure you end up with a solid and long-lasting foundation. 
True foundation professionals take time to: ● Invest in quality foundation design● Follow the best engineering practices● Closely analyze geotechnical reports● Perform testing when needed● Use the best materials from reputable manufacturers● Track installation data in real-time to ensure quality ● Check and re-check their installation
Foundations are complex, and there's never going to be "one solution" that's right for every single scenario. Helical piers could be an ideal solution for your project, or maybe there's a different foundation technology that would be a better fit. Nothing is perfect, and I won't pretend that helical piers should be used for every project without exception.

Challenging site conditions and huge loads made helical piers a perfect foundation solution for this energy storage system project

What I will say, however, is that the claims people make about helical piers being more prone to failure than other foundations is nonsense. If a helical foundation is used for the right situation, designed correctly, and installed to specification, it's every bit as durable (if not more so) than other solutions.

If you're curious how you can actually find true foundation experts among all the dangerous amateurs out there, I wrote a post about that exact topic that you can check out by clicking right here. There's even a free cheatsheet to help you find great foundation contractors with ease.

Helical piers, like anything, can fail if they're not used the right way. That doesn't mean the technology itself is a problem, it means the people using the technology aren't doing it correctly.

If a drunk driver crashes their car we don't blame the vehicle... we blame the person who got behind the wheel after drinking. In the same way, we shouldn't blame any foundation solution that fails if it wasn't used as intended.

That goes for helical piers, concrete, or driven piles.

Conclusion

There's only one way to say this...

Helical piers are not "more prone" to failure compared to other foundations.

The people who loudly proclaim that (usually on social media) are either pot-stirrers or are chasing an agenda of their own. If you've read my other blog articles then you know my goal is to give you the straight facts and let you decide what to do with the information.

That brings me to one last point. Helical piers aren't right for every single project.

There's going to be situations where other foundation solutions perform better or make more sense. I'm not shy about saying that. Any helical contractor worth their salt knows it's better to be honest and open, not shoe-horn a helical solution where it doesn't belong.

Long and short is that helical piers are a reliable deep foundation technology that's used across the world. If there was an insidious problem with the technology, multi-billion dollar companies wouldn't trust them to support critical infrastructure. The rare helical pier failures we see can always be traced back to bad manufacturing or installation practices.

If you're curious about helical pier foundations, or want to know more about avoiding foundation failure, get in touch with our team by scrolling down.