Session: 10-04-01 Anchors and Moorings 1

Submission Number: 156927

Post-Installation Consolidation of Helical Anchors in Clay 

Helical piles have emerged as a promising foundation solution for offshore wind turbines in deep-water environments, providing stability and installation efficiency. While extensive research has focused on understanding the behavior of helical piles during installation, the consolidation process in the surrounding soil post-installation remains insufficiently explored. Accurate prediction of this consolidation behavior is critical for long-term stability, as it affects load-bearing capacity and settlement over time. Traditional methods, such as piezocone penetration tests, provide valuable estimations of soil consolidation coefficients. However, due to the geometrical and load transfer differences between helical piles and piezocones, these methods cannot fully capture the unique consolidation process of helical pile consisting of a central shaft and a helix (or multiple helices).

This study addresses this gap by reporting centrifuge tests exploring the consolidation behavior of helical piles installed under varying advancement ratios (AR), enabling detailed monitoring of excess pore pressure dissipation. Comparative analyses with piezocone dissipation tests reveal key differences in pore pressure response, driven by distinct soil remolding and consolidation mechanisms around the helical pile. From these observations, an 'operative' coefficient of consolidation is proposed, aimed at more accurately predicting consolidation durations for helical piles under specific loading and site conditions. The findings offer critical insights to refine helical pile installation strategies, optimize post-installation performance, and enhance foundation design for offshore wind applications in clay soils.

Presenting Author: Yinghui Tian University of Melbourne

Presenting Author Biography: Dr Yinghui Tian is a full professor, Fellow of Institution of Engineering Australia, currently as an ARC (Australian Research Council) Future Fellow, working at the Department of Infrastructure Engineering of the University of Melbourne. His research background is offshore geotechnics and he is currently focusing on research supported by the ARC Future Fellowship.
He is the recipient of the Institution of Civil Engineers (ICE) David Hislop Award for the best paper on offshore engineering in 2017. He has produced a total of 225 publications (125 journal papers, 72 conference papers, 3 book chapters, 25 technical reports for industry projects).