FUNDEX – The full displacement bored pile system

To manufacture the pile, a tube fitted with a drill point is hydraulically pressed into the ground and rotated. The resulting system pressure is continuously monitored while laying the foundation and aligned with a point-bearing diagram. The system pressure serves as proof that the pile foundation is technically flawless and is thus documented fully.

Applying a vertical force of 250 kN and a torque of up to 450 kNm, a thick-walled steel tube with a point at the bottom is pressed into the subsoil and rotated using a hydraulically driven rotary table. The drill point is positively connected to the tube through a corresponding tooth, such that a jointing compound laid on the tooth seals the tube tightly from groundwater seepage.

The cast-in point has screw threads that enable lateral displacement of the soil and compact the soil surrounding the pile. By pressing and rotating, a hole is created in the ground, which is later filled with concrete until a finished pile is formed.

After reaching the required depth, it is checked whether the driven pipe is dry. Then the connection reinforcement is placed in position and concrete is poured for the full pile length. On pulling the casing pipe by turning it to the left and right, the concrete goes to the bottom of the tube. The drill point remains in the subsoil as the pile footing.

The concrete is hardened due to the rotational movements and the profiled outer surface of the finished pile takes shape. After the concrete hardens,

the finished pile can be cut to its required height and the connection reinforcement can be exposed.

The basic equipment for manufacturing the pile with leader and drive unit can be moved with the help of a crawler. To change the direction, the device is lifted from the ground, the moving mechanism is rotated in the new direction and the process is repeated after lowering it. The building site is thus barely damaged.