CFA PILING

CFA Piling Brochure

CFA piles are also commonly known as auger-cast piles or auger-cast-in-place piles. They are constructed by drilling a slender hole into the ground utilizing a hollow stem auger, then pressure pumping grout or concrete through the hollow stem of the auger as it is slowly being retracted. If required, a reinforcing cage or centre bar can be installed immediately after the auger is fully withdrawn.

Driven Piling Brochure

CFA piles are suitable for most soil types, but are particularly suited to collapsible soils with high water tables. This system offers two distinct advantages: there is no need for temporary casing, and the productivity rates are extremely high in comparison to standard bored piles.

CFA PILING ADVANTAGES

  • Good side shear bond in cemented materials

  • Can be installed in very long lengths

  • Low noise / vibration

  • Easy construction in cohesive soils

  • Faster productivity than bored piles

  • No need for casing due to sloughing/seepage as you do with bored piles

  • Partial soil removal during construction increases lateral compression and bearing capacity

CFA PILING DISADVANTAGES

  • Cold weather temperature limit on installation

  • Spoils are generated that need to be handled, adding costs

  • A higher waste of concrete as a percentage than traditional bored piles

  • Difficulty drilling through very hard bearing layers

APPLICATIONS

Continuous flight auger (CFA) piles have been used for more than three decades globally but are a relatively new locally to Canada. CFA piles are
constructed with a hollow stemmed continuous flight auger that is rotated into the ground to the required depth. As the auger is withdrawn, concrete is pumped down the hollow stem under balancing pressure forming a shaft of liquid concrete to ground level. A reinforcing cage is then inserted manually, with equipment, or a vibrator. CFA piles are suitable for most construction projects in commercial, institutional or light/medium industrial applications as well as for excavation support (tangent or secant walls).