^Supra® pile

Specifications

The soil displacement auger is driven into the ground together with the outer casing. The screw thread loosens and removes the soil at the location of the outer casing, causing the rest of the soil torise around the drilling location. 

The outer casing is then lowered to a certain depth and detached from the ground displacement drill by rotating it in the opposite direction for a short time and also applying axial pressure. This causes the pins to move out of the recess in the drive plate, so that the pins are beyond the drive plate and further rotation can continue. The outer casing therefore remains suspended at that height.

The ground displacement drill is then lowered to the desired depth. First, the reinforcementis placed, then concreteis poured , and finally the hollow tube is withdrawn while the remaining cavity is filled with concrete. When the thickening of the hollow tube reaches the pins of the outer casing, the outer casing is also pulled up.  Afterwards, a larger reinforcement cage can be pressed over the first one.

An additional result of the outer casing is that the foundation pile is thicker at the top. The depth to which the outer casing is driven into the ground by the soil displacement drill determines how thick the foundation pile is. An advantage of being thicker is that the final foundation pile is more resistant to bending moments, usesless concrete, and drillsfaster due to its smallerdiameter.

The length of the outer jacket determines the depth to which the outer jacket can be taken. Incidentally, the screw thread does not need to be applied over the entire length of the outer jacket. An initial section of, for example,1 meter is sufficient.

In summary, the invention can be described in more general terms by the following characteristics:

• a ground displacement drill with a hollow tube and a drill bit;
• an outer jacket;
• where the outer jacket can be placed around the hollow tube of the soil displacement drill, but preferably has a diameter that can even be larger than the outer diameter of the drill bit.
• whereby the outer jacket is provided with external threading on at least a lower portion;
• wherein first coupling means are provided between the soil displacement drill and the outer casing, so that the soil displacement drill can take the outer casing with it into the ground in the axial direction and in the direction of rotation, and can disconnect to continue independently without taking the outer casing with it; and 
• wherein secondary coupling means are provided which can pull the outer casing out of the ground in the axial direction.