Helical Piles
MANUFACTURING HELICAL PIPE PILES FOR LOADS UP TO 500 TONS
IDEAL manufactures a wide range of round shaft helical pipe piles and anchors and round corner square shaft (RCS) helical screw piles and anchors. All products can be bare or galvanized steel. With helical pipe pile shaft diameters up to 24”, we are the leaders in the high capacity helical pipe pile industry.
Our highly efficient production processes and principles combined with our commitment to consistent quality allow us to provide superior products with some of the shortest lead times in the industry. The IDEAL team is often called on to fabricate custom piles and brackets to exact client specifications or designs. This is another area where our design and production teams have become highly recognized for their innovation and skill. Our unique approach to design and production allows us to provide you numerous benefits whether you’re an installer, contractor, or engineer. All of our standard Helical Piles, Helical Anchors, and associated Brackets and Hardware are ICC-ES Certified under ESR-3750-IDEAL Manufacturing, Inc. This includes 1.50” RCS (solid square shaft), 2.875” x .203” W.T., 2.875” x .276” W.T., 3.500” x .216” W.T., 3.500” x .300” W.T.
Advantages of Helical Piles
WIDE RANGE OF ALLOWABLE LOADS
Suitable for supporting a deck, a dock, a transmission tower, or a high rise building. From a few hundred pounds to 500 tons, there is a helical pile that can meet the design requirements.
EASE AND SPEED OF INSTALLATION
Not quite finger-snap fast, but it’s hard to beat the ease and speed of installation with helical piles.
NO DEPENDENCE ON WEATHER
Barring the obvious, such as thunderstorms and tornados, Helical piles can be installed in any weather or temperature.
CAN BE EASILY REMOVED
Easily removed and reused in temporary applications such as shoring and movable structures.
MINIMAL VIBRATION AND NOISE
Helical pipe piles are installed with almost zero vibration. This is why they’re often a preferred piling method when deep foundations are required near schools, hospitals, historical buildings, or any structure with an already compromised foundation.
MINIMAL MOBILIZATION AND DEMOBILIZATION COSTS
Hauling equipment to and from a site is costly and time-consuming, especially in metropolitan areas. Minimal support equipment is needed for installation. A drive head, torque indicator, and a few other components and you’re up and running. Just by the way, IDEAL offers the most complete drive head packages in the industry.
Additional Advantages:
- Adaptability to a variety of installation angles
- Lower cost than driven or drilled piles – do not go as deep to reach the same capacity
- Ideal for low-headroom and other limited-access areas
- Little or no earthwork and spoil material (a particular advantage at contaminated sites)
- Easy pile cutoffs
- No concrete-related delays
APPLICATIONS FOR HELICAL PILES
A helical pier is a deep foundation. Its purpose is to transfer a structural load to deeper, stronger, and less compressible materials bypassing any weaker and more compressible materials that would be unsuitable for the support of a conventional shallow foundation. As a deep foundation, a helical pier should be considered for most applications that would call for a driven pile, drilled pier, or mini pile. Helical piles and anchors are usually a great foundation solution to any of the applications below whether it’s a new build or existing structure.
- Commercial Buildings
- Mobile Home Anchors
- Tilt-up Wall Anchors
- Work Camp Foundations Towers – Quad Base
- Towers – Monotube
- Utility Anchoring
- Substations
- Lighting <50FT
- Sound Walls
- Bridges/Boardwalks/Docks
- Roadway Signage Traffic Signals Billboards/Signage Generator Bases
- Tie-Downs/Moorings
- Tie-Backs/Wall Anchors Retaining Walls
- Bulkheads
- Shoring Pipeline
- Guy Lines/Wires
- Tanks and Silos
- Underwater Support
- Machine Bases
INSTALLATION OF HELICAL PILES
A helical screw pile is rotated into the ground by using a hydraulic drive head, powered by an excavator. IDEAL requires installers to monitor installation torque and pile alignment during the installation process. This is required for a few reasons.
It is important to have a qualitative assessment of the soils being penetrated at various depths. Using a graph, the recorded installation torque and depth is interpreted against the existing soil data to obtain a correlation that enables a simple verification strategy to be determined.
The soil data is interpreted against the installation torque and a correlation is obtained to maintain the integrity of the helical screw pile during installation as well as mitigate damage by exceeding the allowed torsional strength to any of the pile’s components. Every helical screw pile has a maximum stress level that must not be exceeded in order to avoid compromising the structural integrity of the helical screw pile unit. Check out PROJECT CASE STUDIES and PROJECT INSTALL VIDEOS on our blog. Curious about our helical piles? Don’t hesitate to get in touch with a team member here at IDEAL. You can also get started with a quote for your upcoming project.
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The unit is called a helical pier if it resists compressive loads, which are usually downward. It is called a helical anchor if it resists tensile loads, which are usually upward or inclined. Many helical units function as both piers and anchors.
A helical unit is installed by simply screwing it into the ground. The central shaft may be round or square and it may be hollow or solid. Hollow (pipe shafts) are often preferred, because they provide a greater section modulus for the same cross-sectional area of steel. Pipe shafts, as compared to solid shafts, generally provide greater resistance to installation torques and buckling under compressive loads.
A typical helical unit is shown to the left. It consists of a central steel shaft, to which can be attached one or more steel helices. The central shaft can be lengthened by adding extension pieces as necessary.
Pipe shafts range anywhere from 2 7/8″ to 36″ in diameter, and helices range anywhere from 5″ to 48″ in diameter and are seldom less than 3/8″ thick.
Experience and theory have combined to suggest that the preferred spacing between multiple helices is equal to 3 helix diameters of the preceding helix.
The final component to the helical unit is the Load Transfer Device (LTD). This is used to transfer the tension or compression load from the structure to the helical unit.
Simply put, the helical unit transfers tension or compression load to competent soil strata below incompetent soils.
This is the bracket or load transfer device (LTD). This may also be referred to as a Pile Termination Accessory.
There are many variations available. Here we have shown one of the most common ones used in new construction.
HISTORY OF HELICAL PILES
The first helical screw pile was invented in the 1830s by a blind Irish marine construction engineer named Alexander Mitchell. His design proved to be a major improvement over traditional straight pile designs so Mitchell and his son promptly patented the cast iron screw pile. In 1840 the first screw piles were installed to support the Maplin Sands lighthouse at the mouth of the Thames River. This innovative design caught on and made its way across the pond quickly and before long most of the lighthouses in the mid-Atlantic region were being built on helical pile foundations. There were more lighthouses built on helical pile foundations in the Chesapeake Bay than anywhere else in the world. A total of Forty-two helical screw-pile lighthouses were built on the Chesapeake Bay between 1850 and 1900.
The helical screw pile technology didn’t stay on the east coast. Over the next few years, helical screw pile lighthouses could also be found in the Great Lakes Region and the Gulf of Mexico.
The foundation of a typical screw-pile lighthouse consisted of one central pile installed in the center and then flanked by another six or eight piles around the perimeter. This design increased the anchoring properties and the bearing power of the helical screw piles. These early helical screw piles were often installed by using large torque bars and the power of men, horses, or oxen.
Alexander Mitchell’s helical screw pile design is just as effective today as it was in the late 18th century and continues to be installed around the world.