Axial Capacity of Offshore Piles in Dense North Sea Sands

After describing the predominantly dense sand site conditions encountered in the Leman field of the southern North Sea, attention is focused on a 38.1-m long, 660-mm-diameter steel pipe conductor driven from the Leman BD platform, reporting both the driving records and a full-scale tension test to failure. A summary is then presented of new design methods, which have been developed through recent research and been shown to be more reliable than alternative procedures. Applying the new recommendations to the Leman conditions shows: (1) that they predict the Leman BD conductor test accurately; and (2) that the piles supporting the nearby Leman AD II platform are likely to have compressive and tensile capacities approximately 20 and 65 greater, respectively, than expected from the conventional “North Sea variant” of the American Petroleum Institute RP2A procedure. These results have significant implications when considering potential reconfigurations of the platform's load carrying requirements.