Cased CFA Piling
Cased CFA piles combine the benefits of rotary piles with the speed of installation of CFA piling.
Cased CFA piles are particularly suited to contiguous or secant piled retaining walls as the temporary casing helps to improve the vertical tolerance of the piles. Cased CFA piles can also be utilised for load bearing piles in areas with poor ground conditions such as loose materials or voids. Permanent casings can be left in the ground where contamination is prevalent that may be damaging to the pile concrete.
The pile casing is installed using the twisted casing system, this uses an integral oscillator with a twisting torque of over 30 tonnes, this coupled with an insertion force of over 40 tonnes means we can install casings up to 1200mm diameter in a wide variety of ground conditions. The pile is then formed by traditional methods with the concrete being pumped through the hollow stem of the auger as it is extracted, and then the cage is installed once concreting has been completed, where casings are temporary they will then be extracted.
Our state-of-the-art on-board piling instrumentation system will provide the operator with a live feed of all processes, such as oscillator torque, auger torque, casing depth, auger depth and penetration speeds. The instrumentation system will also facilitate leaving the concrete at a lower depth within the casing thereby reducing the amount of concrete to be trimmed down thus further reducing costs.
The casing can be either temporary or permanent depending on the requirements of the individual project.
Benefits of Cased CFA Piles:
- Improved vertical tolerances
- Improved plan tolerances
- Reduced concrete over break / wastage
- Limits ‘over flighting’ in poor material
- No requirement for bentonite
- Improved appearance of finished retaining wall
- Limited noise and vibration