RB launches new displacement auger piling technique

CDA piling

Roger Bullivant has developed an innovative displacement solution as an alternative method to driven piling or CFA piling where minimal spoil/muckaway is required. We are building on our success with Continuous Helical Displacement (CHD) piling with our small new diameter displacement pile – CDA – our Continuous Displacement Auger. This technique has the benefits expected of a CFA or bored pile in terms of vibrations and noise but provides additional benefits over this conventional technique. CDA is suitable for light to moderately loaded piles, typically up to 500kN compression loading across the residential, commercial, and industrial sectors, and is suitable for a range of soils including soft, stiff clays, silts, and loose granular soils. The benefits of CDA piling involve using less concrete per linear metre of the pile than our higher capacity CHD pile and providing higher compressive load capacity than a comparable size and length CFA pile.

Where can you use CDA piling?

CDA piles are ideal for low rise housing schemes, for example, houses that are two to three storeys or low-rise apartments. This technique can be used for school/education complexes, commercial buildings, or industrial buildings. CDA can be designed to account for a variety of loadings including heave situations where the pile design can allow for upward movement of the ground around the piles by introducing specific reinforcement.

Why you should choose CDA piling?

CDA is our new, small diameter displacement pile – up to 40% shorter than 300mm Continuous Flight Auger (CFA) piles to achieve similar compressive loadings, with associated valuable savings in volume of concrete. This provides an outstanding option for reducing materials and increasing sustainability characteristics on residential, commercial, and industrial schemes as cement production is estimated to account for 6-7% of man-made greenhouse gas( predominantly carbon) worldwide. Not only this, but the reduced volume of concrete being installed in the ground reduces the number of concrete truck journeys to the site. At Roger Bullivant, we are constantly striving for new innovative ways to work to make our product more environmentally friendly.

How does Continuous Displacement Auger Piling work?

Upon setting the rig at the required pile position, our bespoke displacement tool penetrates the working platform and underlying soil to a depth predetermined by an experienced Design and Engineering team. Once the design depth is achieved, concrete is pumped through the rig as the CDA tool is extracted, concreting the pile back up to the working platform level.

Boring (the drilling of holes into the ground) and concreting are computer-controlled and recorded using onboard instrumentation to ensure high-quality piles are constructed. This also allows remote monitoring and data capture and our bespoke rigs are easily converted on site between CFA, CHD, and CDA piles so a combination of these techniques can be used to achieve the requirements of a wide range of schemes. The required reinforcement for the pile is installed after the pile has been concreted. This method of installation by displacement produces a pile that is more efficient in compression than a traditional augured pile, resulting in shorter piles to achieve the required loadings and overall quicker installation! Since this is a displacement technique, less mess is generated.

What are the advantages of CDA piles?

  • Less environmental impact – CDA uses less concrete, requires less spoil removal, and significantly reduced associated vehicle and plant movement. Reducing the carbon footprint of your site.
  • Offers a higher compressive load capacity than a comparable size and length CFA pile.
  • Reduced spoil.
  • Saves money in the reduced spoil.
  • Improved installation programme compared to CFA.
  • Suitable for light and moderate loads up to 500kN.

For more information on this technique click here. For all enquiries please email info@roger-bullivant.co.uk or alternatively call 0845 838 1201 to speak to your local RB office.