CFA Piles, also known as auger cast piles or Augefred Cast in Place (ACIP) piles, are deep foundation elements ideally suited to open sites and/or where speed of installation is desired.

The technique is vibration-free and since drilling for pile installation is a continuous operation, no casing is required. However, since continuity of operation is integral to the integrity of the piles, this technique is limited to soils. McKinney Drilling provides auger cast services throughout the USA.

Common Uses

  • Structural support systems for buildings, retaining walls, tanks, bridges and piers, and high mast lighting

Technical Details

CFA Piles (Auger Cast) are constructed using a hollow stem auger fitted with continuous flights. Pile diameters typically range from 12 to 24 inches. Piles are installed in groups and tied into a pile cap. A load test is typically required by the project geotechnical or structural engineer to verify design assumptions.

The auger is rotated into the ground to design depth or to refusal in a continuous operation. As the auger is advanced, the flights are filled with soil, and additional drilling flights are added to achieve the required bearing depth. This provides lateral support and maintains the stability of the uncased hole. At design depth, pumping of grout or high-strength concrete is initiated through the hollow stem as the auger is gradually withdrawn to the surface. Control of pressure and grout volume is critical to continuity of the pile throughout its length. A full-length center reinforcing bar may be added to the wet column immediately after the auger is withdrawn.