The JACBO auger drilling technique.
Construction of a drilled pile in detail.

Following determination of the individual drilling points based on the pile plan by a surveyor, the actual drilling process begins. The tip of the auger is positioned precisely above the determined drilling point.

The auger is drilled down to the required depth, computer-guided, vibration-free and under continuous digital monitoring in order to adapt the drilling process according to the prevailing ground conditions. When the required depth is reached, concrete is pumped into the pile hole through the central tube of the auger.

The pressure generated opens the closure cap at the tip of the auger and the concrete automatically pushes the auger together with drilled
material to the surface without rotation. The concrete pressure is controlled digitally and can be increased as required in order to prevent lateral contractions of the pile diameter.

As soon as the concreting process is completed, the procedure is repeated at the next drilling point. Simultaneously, the previously constructed pile is brought to the required height using a mini excavator. By means of this method, capping of the drilled pile heads can be limited to 10–20 cm. The otherwise usual time-consuming pneumatic drilling work is dispensed with.

During the last step, the connecting reinforcement is driven into the fresh concrete. Depending on the pile diameter, the reinforcement may have a length up to 12 m. A positive side effect: Driving in the reinforcement further compacts the concrete at the pile head, which is then covered with protective sheeting to protect it against dirt and drying out.