Open bore piling, also known as augered piles or continuous flight auger (CFA) piles, is a method used in foundation construction. It involves drilling a borehole into the ground using a hollow-stemmed auger continuously rotated into the soil. Here’s how the open bore piling process typically works:
Drilling:
An open-bored piles contractor often uses a drill rig to create a borehole by rotating a hollow-stemmed auger into the ground. The auger has a helical flighting or blade that helps remove soil as it rotates. The diameter of the borehole is usually larger than that of the finished pile.
Soil extraction:
As the auger is rotated and drilled deeper, soil is extracted from the borehole and stored within the hollow stem of the auger. The auger continues drilling until it reaches the desired depth or a stable soil layer.
Reinforcement and concrete placement:
Once the desired depth is reached, reinforcement, such as steel reinforcement cages or prefabricated reinforcement elements, is inserted into the borehole. Afterward, ready-mixed concrete is pumped through the auger’s hollow stem into the borehole, displacing the stored soil.
Auger extraction:
After the concrete is placed, the auger is slowly extracted from the borehole while concrete is pumped to maintain a stable column of concrete within the borehole. The auger is gradually withdrawn, ensuring that the concrete maintains its position and integrity.
Finishing:
Once the auger is completely removed, the top of the pile is leveled, and a capping or structural element is often added to provide a connection point for the superstructure.
From the Best Piling Contractors in London to elsewhere in the world, Open bore piling is used for various construction projects, such as building foundations, bridges, retaining walls, and other structures that require deep and stable support. It offers several advantages, including high productivity, minimal vibration, suitability for various soil conditions, and the ability to penetrate through different soil layers and reach significant depths. It’s worth noting that specific details and variations may exist in the open bore piling process depending on the project requirements, soil conditions, and local regulations. Professional geotechnical engineers and foundation specialists should be consulted to determine the most suitable foundation method for a particular construction project.
Where can open bore piling be used?
Open bore piling, or augered piles/CFA piles, can be used in various construction projects requiring deep and stable foundation support. It is commonly utilized in the following applications:
Building foundations:
Open bore piling is commonly used for constructing foundations of buildings, including residential, commercial, and industrial structures. It provides a reliable and stable support system for the load-bearing elements of the building.
Bridges and viaducts:
Open bore piling is often employed in bridge and viaduct construction to create deep foundation support for the bridge piers or abutments. It helps distribute the weight of the bridge and withstand the lateral forces.
Retaining walls:
Open bore piles can be used to support retaining walls, particularly in areas with challenging soil conditions or where a deep foundation is required to resist earth pressure.
Noise barriers:
Open bore piling can be used to construct noise barriers alongside highways or railways. It provides stability and prevents noise transmission by creating a solid foundation for the barrier.
Infrastructure projects:
Open bore piling can be applied in various infrastructure projects, such as tunnels, underground structures, water treatment plants, and sewage treatment facilities. It helps establish a stable foundation in different soil conditions.
Industrial facilities:
Industrial facilities, such as factories, power plants, and warehouses, often require deep and stable foundations. Open bore piling can be an effective method to create a reliable support system for these structures.
Slope stabilization:
In cases where slope stability is a concern, open bore piling can be used to create retaining systems or stabilize slopes by providing structural reinforcement.
It’s important to note that the suitability of open bore piling for a specific project depends on factors like soil conditions, load requirements, geotechnical considerations, and local regulations. Professional geotechnical engineers and foundation specialists should assess the site conditions and determine the most appropriate foundation method for each project.
Who carries out open-bore piling
Open bore piling, also known as augered piles or continuous flight auger (CFA) piles, is typically carried out by specialized foundation contractors or piling companies. These companies have the expertise, equipment, and experience necessary to perform open-bore piling effectively and safely.
Foundation contractors or piling companies typically have a team of skilled professionals, including geotechnical engineers, project managers, and piling operators specializing in various piling techniques. They are responsible for planning, executing, and overseeing the entire open bore piling process.