Concrete piles are made from prestressed reinforced concrete. Pile-head reinforcement is often used to prevent damage to the head as the pile is being driven into the ground or to transfer the moment from the concrete structure.
Prefabricated concrete piles are the most widely used type of foundations in the Netherlands. Ballast Nedam Funderingstechnieken specialises mainly in the piling of large, heavy prefabricated piles. Lengths over the 30 m and diameters of approximately 45 or 50 cm, respectively.
Properties of prefabricated concrete piles
Prefabricated concrete piles are conventional soil displacement piles: during the driving process, the pile displaces the existing soil for the entire length of the pile.
Prefabricated concrete piles are suitable for every type of soil. The pile head can also be driven below ground level.
Prefabricated piles can be driven obliquely (so-called shore) to resist lateral forces, this is necessary with structures such as bridges and viaducts.
The piles are available in lengths of up to 38 metres, a limit determined by the maximum lifting capacity and the space available in the factory where the piles are made.
The piles are increasingly driven with hydraulic hammers, which generate lower noise levels than diesel hammers.
Prefabricated concrete piles have a higher load-bearing capacity than wooden piles.
Prefabricated piles are relatively cheap and, together with vibro piles, offer the most economical solution when noise and vibration are not an impediment.