Rock & Alluvium has been putting its first rotary piling rig through its paces on a new residential development in Fulham.
The company has been using the Soilmec SR30 to install 1200mm diameter bearing piles for the scheme, which was carried out in combination with CFA piles for the secant pile wall to reduce the number of piles and cut the construction programme.
The piles form a secant pile wall around the riverside development and bearing piles for the mixed use development which will include a new supermarket, which is being undertaken for Barratt Developments.
The first phase of the job – Rock & Alluvium’s largest ever contract at £3.3M - includes a 498m long perimeter wall which consists of 1,033 piles with 600mm and 750mm diameters to enclose the site and enable excavation for the construction of an undercroft car park.
“We considered sheet piles but they weren’t viable because there was insufficient time in the programme to order piles of the necessary thickness and extensive propping would’ve been required,” said Rock & Alluvium head of operations Nick Dewey. “On top of that piles caps needed to be closer to the wall that a propped, sheetpiled solution would allow.”
The wall – retaining between about 3 and 5m with minimum embedment of 6m – includes a 167m temporary section formed of 395 600mm piles which enables construction of phase 1A to get underway as soon as possible. These piles will be removed as the project progresses because they run across the footprint of the car park.
According to Rock & Alluvium, their early involvement in the scheme meant that the bearing pile layout could be configured around the capabilities of its fleet with the Soilmec rig drafted to assist on the 866 load bearing piles.
Work on the 20 week piling contract is expected to be finished at the end of February.