Rotary displacement or CHD piling systems provide improved soil strength, pile capacity and load transfer to the surrounding ground. This approach also offers a reduction in overall foundation costs by reducing pile lengths and diameters, as well as substantially reducing or eliminating the cost of pile spoil disposal.
Drilling technique: Similar to CFA / Replacement Pile methods however, the auger string, instead of breaking down the soil for extraction from the bore, forces the ground away from the bore laterally. This results in very high capacity relative to the bore diameter as the shaft capacity is enhanced significantly.
Ground conditions: Displacement piling is amenable to a medium range of ground conditions from loose or medium dense sands and gravels through to soft or firm clays. The technique is not recommended in very dense or stiff soils as the torque required to rotate the auger is very large and the improvement in shaft capacity is diminished. However, for this kind of challenging ground, other piling techniques should be explored.
Advantages of Displacement Piles:
Sectors: residential, commercial (multi-storey)
DISPLACEMENT PILE CONSTRUCTION SEQUENCE