Olivier pile

An Olivier pile is a drilled displacement pile:. This is an underground deep foundation pile made of concrete or reinforced concrete with a screw-shaped shaft (helical shaft) which is performed without soil removal.
History.
The Belgian Gerdi Vankeirsbilck applied for the production patent for the Olivier pile in April 1996. This technique was implemented by his own company and various licences have been granted in Belgium and abroad. Due to its screw-shaped shaft, the Olivier pile is particularly suitable for use in soils with low load-bearing capacities, such as clay and loam. In 2018 a patent was applied for drilling without the use of a lost bit.
Description.
An Olivier pile is drilled into the ground by the use of drilling rig with a top-type rotary drive with variable rate of penetration. A lost tip is attached to a partial-flight auger which, in turn, is attached to a casing. The casing, which is rotated clockwise continuously, penetrates into the ground by the action of a torque and a vertical force. At the desired installation depth, the lost tip is released, and the reinforcing cage is inserted into the casing. Concrete is then placed inside the casing through a funnel. The casing and the partialflight auger are extracted by counter-clockwise rotation. The shaft of the Olivier pile has the shape of a screw.
The casing has an external diameter of 324mm (12.75"), with a wall thickness of 25mm (1"). The casing consists of several parts assembled with watertight couplings, which are strong enough to handle the maximum torque produced by the rotary drive. The various auger heads, for the various diameters of the Olivier Pile, all have a larger diameter than the casing.
Common diameters of the auger head