Analytical method for predicting pile running during driving

Abstract

Most offshore structures, such as conventional oil and gas jacket platforms or wind turbines, are typically supported by driven large-diameter steel piles. The piles resist the loads of the superstructure and environmental wind and wave forces. Pile running is a major hazard associated with the installation of driven piles in a layered seabed. An analytical method based on Newton's second law of motion is proposed to predict pile running. Two methods are used to calculate the soil resistance to dynamic penetration: (1) the conventional American Petroleum Institute (API) method, where the strain rate dependency and remoulding of the surrounding soil are considered, and (2) the Cone Penetration Test (CPT)-based method, which accounts for friction fatigue. The drag resistance in the context of fluid mechanics has also been considered for pile running. The velocity at the start of pile running was determined by the energy delivered by the piling hammer. A numerical programme was implemented and validated, and then used for three case studies; the results obtained were in good agreement with field measurements. The method presented in this study is dependable for analysing pile running and can provide significant support for pile installation assessment and risk management in offshore engineering design.