SPI Piling Ltd, were engaged for the Design, Supply, installation and extraction of AZ36-700N 10.0m piles over a 4 week period using a combination of Leader Rig, Sidegrip and Conventional piling either side of River "Great Ouse" to form 2 cofferdams for bridge abutment works on the new Ely bypass.
Cofferdam plan dimensions 20m x 24m. Supply, installation and extraction of 150 nr minimum PU22-1 section sheet piles in varying lengths (10m to 11m long) to form a temporary cofferdam to allow excavation and casting of Pier 2 foundation.
The rectangular cofferdam will be 23.6m X 20.6m internally (40 piles x 35 piles).
Because of the expected ground conditions (stiff clay overlying dense sands) all sheet pile and clutch positions had to be pre-augered 450mm diameter at 600mm centres to the full depth of the sheet pile toe. Augering was carried out using a continuous auger string (approximately 12 metres long) and auger drive mounted to the mast of the Telescopic Leader Rig.