Auger displacement piling is a technique that was first developed in the 1960s. It is ideal for use on contaminated land as the method is spoil-free. NCE reports.
Able Piling is promoting the use of auger displacement piling in the UK. Founded in 1994 the contractor has established itself as a regional mini-piling contractor.
After becoming part of Franki Foundations Belgium it has reintroduced auger displacement techniques to the UK.
Both methods have had previous use in the UK by other contractors under licence from Franki.
The techniques were developed worldwide by Franki engineers, Their development started in the 1960s with real improvements in the 1970s. The unique development of the dedicated Atlas rigs with their combination of 40t.m torque independent of up to 80t vertical thrust maintains the ability to form vibrationless and spoil free piles.
“Pile capacities and settlement characteristics are invariably better than for equivalent, more conventional piles, leading to a reduction in pile lengths”
The Omega system utilises high torque masted rigs that can offer suitable continuous pull down along with advanced auger shaping developed through many years of experience. The choice between systems is a combination of ground conditions, load requirements and/or production economics.
The development of auger displacement piling has been assisted by a large amount of research in the UK and in Europe.
Atlas and Omega piles are cast in-place full displacement piles formed by the pushing of a hollow stemmed auger into the ground, such that no vibration is induced and no spoil is created.
Reinforcement can be placed either prior to or after the concreting of the pile shaft.
Some examples of Able projects using Atlas or Omega piling techniques are: Crest Nicholson Regeneration (540 piles), Mullaley Special Projects (200 piles), C&N Homes/Coinford & WH Roads (951 piles), Higgins (340 piles), Belway Homes (358 piles), Morrish Builders (103 piles) and Blenheim House Construction (140 piles).
The Atlas and Omega augers and techniques give reduced ground disturbance.Full displacement techniques give improved load transfer to the surrounding ground in comparison with other bored or augered piles.
Better pile capacities
Pile capacities and settlement characteristics are invariably better than for equivalent more conventional piles leading to a reduction in pile lengths (for same diameters) required.
Major benefits of the Atlas and Omega systems can be realised when a site’s upper ground layers may be contaminated.
Piling without producing contaminated waste is the most obvious of advantages but the greatly reduced risk of both cross contamination between ground layers and creation of a preferential pathway gives these piling techniques further positive advantages.
The benefits of spoil free piling go beyond the saving in not having to cart away and dispose of piling waste. No spoil on site leads directly to cleaner surroundings and reduced attendance costs - no need for an excavator dedicated to the piling operation, no wheel cleaning/road cleaning etcetera.