Deep foundation systems
CFA Piles
Continuous auger drilling with controlled concreting.
Method overview
Continuous auger drilling with controlled concreting.
CFA stands for Continuous Flight Auger piling. A pile is formed by pumping concrete through the hollow auger stem; reinforcement is then placed into the fresh concrete. Drilling and concreting form a controlled sequence of construction.
Low vibration
An installation option with lower vibration than driven piling methods.
Continuous construction
Drilling and concreting form a complementary sequence in suitable ground conditions.
Process control
Concrete pressure, volume and auger withdrawal rate are assessed together.
CONTINUOUS FLIGHT AUGER
Installation stages
Preparation and setting out
Pile positions, the working platform and concrete supply are planned.
Continuous auger drilling
The hollow-stem auger advances to the design depth.
Concreting and withdrawal
Concrete is pumped from the base as the auger is withdrawn under control; pressure and volume are monitored.
Reinforcement and completion
The cage is placed into fresh concrete; construction records and the pile head are completed.
Applications
- Residential, commercial and industrial building foundations
- Suitable urban sites where vibration effects are important
- Piled retaining systems where specified in the design
Quality and site control
Drilling depth, verticality, concrete pressure and volume, and withdrawal rate are critical parameters. Concrete workability must allow reinforcement placement. The soil profile, obstructions and equipment capacity inform method selection.
Frequently asked questions
When is the reinforcement installed?
In standard CFA construction, the cage is placed into fresh concrete after concreting and auger withdrawal have been completed.
Is it suitable for every soil?
No. Very hard layers, large obstructions, reinforcement requirements and equipment limits affect suitability. Selection follows the ground investigation.
Every sound project starts with the right foundation.
Contact Geofond to assess the ground investigation, structural loads and site requirements together.