What are Helical Piers? A Look at the Purpose of Them for Commercial & Residential Structures
Whether you’re in commercial construction, an architect, or a homeowner, you know that building any kind of structure requires a strong and stable foundation. Think about when you’re driving or walking across a bridge. If you see chips in the concrete or an exposed rebar, you begin wondering about the structural integrity of the bridge. Is it safe? A common and effective solution for ensuring the strength and stability of a residential or commercial structure is the use of helical piles.
What Are Helical Piers and Helical Piles?
If you’ve conducted any research, you may have come across two competing terms – helical piers and helical piles. So, what’s the difference? The truth is the two terms are interchangeable and refer to the exact, same product. They both refer to deep foundational elements that leverage compression or tension to transfer/resist vertical and horizontal loads.
Helical piles, also referred to as screw anchors, screw piers, screw piles, helical piers, helical anchors, helical screw piles, and screw foundations are embedded deep underground during the installation process in order to distribute the massive weight that rests on top of them.
The only difference between these two key terms is the size and materials used. Helical piles are commonly made of concrete, long steel, or wood while piers include materials like concrete/masonry. In order to reach their intended carrying capacity, end-bearing piles are placed in rock or dense soil. They can also shoulder the load via the friction created between the surface of the pile and the soil that surrounds it.
Often, piers/piles will leverage cement grout to elevate the surface friction with the soil. Once installed and positioned correctly, helical piers/piles can either be attached to an existing foundation or utilized for new construction.
What is The Purpose of Helical Piles?
Helical piles/piers resemble hollow steel tubes and are an effective way to stabilize structures of all types and sizes. By anchoring the weight of the loan to the surrounding ground, like a driven pile, these products provide unparalleled foundational support. In order to work adequately, they are installed deep into the ground – sometimes even section by section for optimal functionality.
Helical piers are highly effective when dealing with challenging soil conditions. They’re also used in a variety of applications – from repairing weak foundations to building new structures to stabilizing existing foundations that will be taking on heavier loads. When it comes to the restoration process, piles can be used on a wide spectrum of structures, such as bridges, docks, or railroads that reside on a harbor, wetlands, or areas with weak soil.
How do Helical Piles and Helical Piers Work?
The screw piles are installed directly into the soil. Load capacity is predetermined before beginning installation, in order to calculate where they should be positioned. For example, you’ll want to space them at the right intervals to ensure they are equally sharing the weight of the structure on top.
Creating a solid foundation is paramount. Trains, for example, can be derailed if their tracks settle from softened, oversaturated, or weakened soil. Just a few inches is all it takes to throw a structure out of alignment.
During the installation process, a Hydraulic drill motor is attached to an excavator, screwing the piles/piers into the ground at varying depths. Generally speaking, these are installed between ten and thirty feet below the ground’s surface. The depth is ultimately determined by the size, shape, and build of the structure. If they don’t meet the required torque, for example, they will be screwed deeper into the earth for maximal support.
What Are They Made of and How Long Do They Last?
In order to prevent rusting, helical piers are made of galvanized steel and concrete. They will always vary in size, style, and diameter based on the structure that’s being built or repaired. When it comes to their shape, you can expect to see two types of helical piers – ones with square shafts and ones with round shafts. Square shafts are the preferred choice for areas with tension forces due to their tensile strength and greater yield. Square piles are typically sized 1.5”, 1.75”, 2”, 2.25” and up while round piles come in 2 7/8”, 3.5”, 4.5”, 5.5”, 6.5”, 8”, 10”, and higher. Round shafts are effective for construction projects that require strong lateral stability and will be exposed to compression forces. The bigger the diameter, the more you can expect cost-wise for these helical piers.
Generally, piles are expected to last around one hundred and fifty years. Their lifespans may be longer or shorter – it all depends on the surrounding soil conditions.
Foundations created or repaired with helical piers and piles are an effective way to ensure the foundation is adequately reinforced. Not only are they an economical solution, but they’re relatively quick to install and provide a tremendous amount of strength and stability for various structures. They’re especially handy when it comes to reinforcing a foundation that requires repairs. Whether they’re being used in a residential or commercial capacity, their long life spans and proven efficacy make them a popular choice to use when doing construction projects.