Helical piers are used to level the foundations when a building shows signs of foundation settlement. Helical piers contain components including a round, steel shaft and screw-like plates. When employed for foundation leveling, the helical pier can be screwed into the soil, much like a screw being driven into wood when doing carpentry. Helical piers can support many different types of structures, and they have a diverse range of applications.
Foundation leveling with helical piers involves screwing the helical pier into the ground using a high-torque motor to the point where the pier reaches load-bearing strata and the engineering capacity is achieved. A steel bracket is placed to connect the pier and the foundation wall, and a hydraulic ram then pushes the steel bracket down against the pier. The downward force of this action causes the structure to lift in a similar way to a car being elevated by a jack.
The primary use of helical piers is to transfer the weight of a structure from inadequate, weak soils to more suitable load-bearing strata beneath the surface of the ground. This provides greater stability and reduces the risk of foundation settlement.
Helical piers can also be employed to prevent or lower the risk of foundation heaving if a building is constructed on expansive soils. This term means that the soil changes due to environmental and meteorological conditions.
In both the scenarios outlined above, it’s possible to place a helical pier either before or following construction. In most cases, installation is preferable beforehand, as this is likely to save money. If a helical pier is positioned before construction, the soil should be tested by an experienced, licensed geotechnical engineer. Analysis of the soil and the project will determine whether using helical piers is the right decision.
Did you know that helical piers have equal capacity in terms of tension and compression? This means that they can be pulled up and pushed down with equal force.
As well as being used to level and stabilize foundations, helical piers also serve a number of other important roles, including:
Due to their ability to provide tension strength, helical piers are used widely within the energy industry. The most common uses include anchoring and stabilizing telephone poles and electric pylons, and more recently, solar fields. When the wind blows beneath the solar arrays, the piers keep them firmly anchored, creating an effect similar to that of a boat’s sails. Helical piers are also employed to hold gas lines in the air, and to secure them to the ground. This is particularly critical in colder climes, when the ground can heave as the soil freezes and hardens. Without the use of helical piers, there would be a risk of the ground heaving and the pipes cracking and bending. Helical piers can also be used in the same role to stabilize oil pumps located in crude oil fields.
If you have an expansive retaining wall, this can result in intense soil pressure, which can cause the walls to lean, break, fracture or even fall. To prevent this from happening, helical piers are used to strengthen the wall and hold it back, acting like the anchor on a ship.
Helical pads have also been utilized to create strong, stable launch pads at NASA’s Cape Canaveral base.
Boardwalks are placed to enable us to enjoy nature reserves and other areas of natural beauty without interfering with the landscape or native species and ecosystems. Helical piers are often fitted to secure low-impact boardwalks
The Advantages of Using Helical Piers
Helical piers offer a raft of advantages, including:
- Suitable for delicate, fragile areas
- No risk of overburden or spoils from the soil
- Eco-friendly and low-impact: suited to areas where protecting ecosystems is a priority
- Measurable outcomes and trackable results
- Minimal risk of weather delays: adverse weather shouldn’t put completion at risk
- Rapid installation
- Cure time is not required for cement
- Can be removed very easily if necessary
- Capable of transferring weight immediately following installation
- Lack of vibration enables helical piers to be used close to existing structures
The Installation Process
- Holes are created at specific points to access the foundations
- Concrete is removed to facilitate the placement of the piers close to the foundation wall
- The helical piers are driven down to the torque capacity
- Steel brackets are positioned on top of the pier, ready for lifting
- The structure will be lifted
- The access holes are closed
If you have any questions about helical piers, or you’d like more information, don’t hesitate to contact Rhino Foundation Systems today.