CFA augers

What are CFA Piles?
CFA Piles ( Continuous Flight Auger
are bored piles, made with a continuous auger. It is the most popular
method of execution of the so-called foundation piling.

How are Piles CFA executed?
The set of augers is driven into the ground to the desired depth with a rotary motion
using a vertical drilling rig. Then, through the through-hole core of the augers, the concrete mix
is introduced, which under pressure opens the outlet valve at the bottom of the auger.
The previously prepared mixture is delivered by means of a pump to the side inlet
of the auger or to the drilling rig itself – the so-called “”central concrete drilling rigs””. Along with
the lifting of the auger, the drilled hole is tightly filled with concrete under pressure, which
prevents the soil relaxation. Immediately after pouring the entire cavity with concrete and removing
the augers, the previously made reinforcement is inserted into the filled hole, creating
a CFA pile after cooling.
In addition, central feed drilling rigs allow concrete to be injected without necessity
to stop the auger rotation, as is the case when using a auger with a side
feed system. Additionally, drilling rigs with central inflow do not require disconnecting the concrete feeding
pipe during drilling and connecting it to the concreting operation each time.

Where are the CFA piles used?
CFA piles are used wherever there is a need to build bridges,
CFA piles are used wherever there is a need to build bridges, buildings, acoustic screens or other structures on homogeneous
soils, such as: plastic and hard-plastic clays, soft rocks, as well as sandy soils
with an admixture of gravel and less cohesive soils such as, for example, clay and
dust.

What are the advantages of CFA Piles?
The advantage of this technology of making piles is its relatively low cost, short implementation time
and ease of implementation while obtaining high parameters of the pile.
Due to the vibration-free construction of piles, there are no contraindications for their construction
in existing structures.
CFA pile augers are usually made by our Company in typical diameters Ø300- Ø800.
The augers sections are connected with pass-through joints and are usually ordered in
lengths of 1m, 2m, 3m or more. At the end of the augers set there is a auger with an integrated
cutting head. We are able to make drills of various lengths and
diameters, on request.

Download the technical drawing