THE CONTINUOUS FLIGHT AUGER pile is another form of non-displacement pile.
A continuous flight auger drill is used to excavate a hole and concrete is injected through a hollow shaft under pressure as the auger is extracted. Reinforcement is then inserted after the auger is removed. This creates a continuous pile without ever leaving an open hole.
Continuous flight augering can be used to construct a secant piled wall which can be used as a retaining wall or as shoring during excavation. Once initial piles are set with concrete, other shafts are augured between them, slicing into the original piles, with the new ones receiving rebar. The finished result is a continuous wall of reinforced concrete that aids and protects workers during excavation.
Unlike in the case of bored piles where the three processes of earth boring, installation of reinforcement and concreting are taking place in a separate step-wise order, in CFA, boring and concreting takes place simultaneously.
There is minimal disruption of the earth crust since there is no use of casing
Useful in unstable soil strata.
It is especially important in sites where there is need to significantly reduce noise
Useful in making large projects where minimum vibration is desirable.