GDP: A New Technology for Gentle Driving of (Mono)Piles-Paper

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The Gentle Driving of Piles (GDP) project is developing a quieter alternative to conventional offshore monopile installation. Its novel vibro-hammer applies low-frequency axial vibrations together with high-frequency torsional vibrations. The approach is intended to ease pile penetration and reduce underwater noise, while maintaining satisfactory foundation performance.<br /><br />During the project’s first year, researchers conducted field trials at a reclaimed sandy site at Maasvlakte 2 in the Port of Rotterdam. Nine piles were installed using impact hammering, conventional axial vibratory driving, or GDP. Four test piles were instrumented, and sensors around the piles recorded soil displacement, stress, and pore-water pressure. The team also carried out cyclic and dynamic lateral load tests to assess how installation method relates to post-installation behaviour.<br /><br />The initial results indicate that GDP drove a test pile smoothly through approximately 5 m of soil in just over two minutes, at a fairly steady penetration rate. Preliminary lateral-load results showed no evidence of impaired soil performance after GDP installation. Tests also demonstrated that cyclic loading can cause permanent lateral displacement, particularly when a new, larger load amplitude is first applied; small-amplitude vibrations had little apparent effect on this accumulation.<br /><br />These findings support the feasibility of GDP installation in sandy soil, but are preliminary. Further analysis and comparisons among installation methods are needed to establish its effects on noise, drivability, and long-term foundation performance. The project’s subsequent work includes advanced modelling of pile installation, acoustic emissions, and geotechnical behaviour.

Keywords

Gentle Driving of Piles

GDP project

offshore monopile installation

vibro-hammer

axial vibrations

torsional vibrations

underwater noise reduction

field trials

pile driving

lateral load tests