Continuous Flight Auger (CFA)

CFA piles are suitable for most construction projects. Causing minimum disturbance, they are ideal for noise and environmentally sensitive sites for both load bearing piles and excavation support i.e. contiguous walls and secant walls.

What is CFA used for?

• Noise and vibration sensitive sites
• Interbedded sequences of clays and sands
• Water bearing strata
• Piling in weak rocks
• A broad range of loading conditions
• Retaining walls
• Rapid installation

Basic Technique

A hollow stemmed continuous flight auger is rotated into the ground to the required depth. As the auger is withdrawn, concrete is pumped down the hollow stem while the operator monitors the concrete pressure and flow rate forming a shaft of liquid concrete to ground level. A reinforcing cage is then inserted in to the wet concrete and pushed in by hand, attending excavator or vibrated in.

Advantages

• Minimal disturbance - hence limited risk of damage to adjacent structures
• No casing is required
• Suitable for all soil types
• Ideal for retaining walls
• Speed of installation

Instrumentation

All Quinn Piling CFA rigs are fitted with sensors and a computer based monitoring system as the piles are bored data is sent to the Quinn Piling head office. The system provides instant data on parameters such as:

• Auger depth
• Auger rotation
• Concrete pressure
• Concrete volume
• Productivity

The data is presented in tabular and graphical format analysed on site to produce graphical representations of pile shaft.

 

Please click on the images above to download some case histories. For further case histories please go to our Projects page.