30/04/2025
First use of the Screwsol® technique for McDonnell Piling !
Since 2022, McDonnell Piling has been exploring the innovative Screwsol® technique. Following in-depth analyses and collaboration with several Soletanche Bachy business units, McDonnell has applied Screwsol® for the first time on a residential development project. The result: a 90% reduction in excavated spoil using less materials and shallower piles in comparison to CFA piles.
A cross-BU collaboration
McDonnell Piling began investigating the Screwsol® technique in 2022. The sand and gravels in the Cork region, where McDonnell operates, were ideal for this method. These low-density gravels are easy to drill and allow the auger to displace them efficiently.
To kick off the process, the teams visited Bachy Soletanche in the UK to carry out design analyses. These confirmed that Screwsol® was a viable solution for the soils found in the Cork area.
Next, the teams traveled to Hungary to visit HBM and several project sites, including the BMW factory project. This collaboration helped McDonnell’s teams deepen their expertise in the Screwsol® technique.
Focus on the project
McDonnell used Screwsol® for the first time on the ‘Ford Project’, which includes 12 apartment blocks of up to 14 stories high. The team designed a foundation solution combining CFA and Screwsol® piles. A total of 105 Screwsol® piles, of diameter 430/600 mm, were installed to a maximum depth of 17.1 m. These piles were designed to support a load of 1,800 kN (SWL).
The client was highly satisfied, especially thanks to the 90% reduction in spoil generated and reduction in CO2 emissions when compared to CFA piles. This was a critical factor, as the site was a heavily contaminated brownfield site. Static load tests conducted on site proved that the Screwsol® pile performs on par with CFA piles, even though it is shallower and requires fewer materials. The product has now been validated on the ground, and the McDonnell team is hopeful to secure the next phases of the project using the same technique.
Congratulations to the McDonnell team!
What is Screwsol®?
This technique minimizes soil extraction through a threaded profile, reducing the amount of concrete required. It also allows additional savings by improving soil properties during drilling.
