Constant Flight Augering (CFA)

Also known as continuous flight augering or CFA, is a method of excavation commonly used in geotechnical and foundation engineering and to extract landfill gas from landfill cells and bulk sampling of mine dumps or soul. It involves the use of a continuous flight auger, which is a large, hollow drilling tool with a helical flighting wrapped around its exterior.

In CFA, the auger is drilled into the ground using a drilling rig. As the auger rotates, the helical flighting creates a continuous spiral path, allowing for the efficient excavation of soil or other materials. The soil is trapped within the auger flights and remains within the tool as it is extracted from the ground.

Unlike other drilling methods, CFA does not require the use of drill rods, as the auger serves as both the drilling tool and the conveyance mechanism for the excavated material.

The continuous flight auger can penetrate different types of soil and can be used to drill through more challenging ground conditions, such as cohesive soils or soft rock.

CFA has several advantages, including high productivity, minimal soil disturbance, and the ability to drill in unstable or water-bearing ground conditions. It is also an effective method for creating foundation elements that provide structural support and stability to buildings and other structures.