The bored piles installed by the CFA technology (CFA – Continuous Flight Auger) have become the most commonly used because of theirs high efficiency, bearing capacity, technological effectiveness and reliability. This method is the best to install piles on a site with the irregular bedding of soils including sand and clay interlayers.
The core of this technology is using of the continuous flight auger. The auger column is driven up to the target depth. After this along the inner tube of the auger a concrete pump conveys concrete up to the place. During the concreting it is necessary to remove the auger column from the borehole. Having the borehole full of concrete it is required to put a space frame specified by a project into this borehole with the help of a vibrator.
Advantages of the CFA technology:
High quality of a borehole’s concreting as concrete is delivered under pressure.
Pile drilling in dense sand layers.
No ground fluctuations.
The CFA method is very useful in narrow urban conditions.
Using of this method allows working very closely to the existing buildings.
To save time during a borehole drilling it is not necessary to change an operating tool.
Specifics of the technology:
It is quite possible that there will be higher consumption of concrete on a site with soft ground.
Driving of a reinforced frame is required using of a vibrator.