UK FOUNDATION contractor Aarsleff Piling was brought in to install precast concrete piles for the three and four storey homes and apartments for KingsOak Homes on the former Trevelyan school site in the shadow of Windsor Castle, Berkshire.
Its £250,000 (e370,000) contract involved installing 740, 250mm square piles between 9m and 14m long. Supplied by the firm's subsidiary Centrum Pile, these were driven by a Banut rig and will carry a maximum 500kN working load.
Ground conditions were about 2m of made ground over 2m of loose to increasingly dense sand over weathered London Clay, which became stiffer with depth.
Nearly 100 of the piles were preaugered to a depth of 3m to 5m to eliminate the risk of any vibration or disturbance to an area very close to a public subway.
KingsOak followed on behind breaking the pile tops to expose reinforcement to allow connection to the buildings' cast insitu ground beams.
Up to 45 piles were driven each day, with 300 installed in just eight days to allow ground works to start early. Piling was finished two weeks ahead of programme.
The development is very close to other housing, but independent noise and vibration monitoring tests showed work was within the required limits.