Effect of Material Law on the Behavior of Offshore Steel Piles under Cyclic Axial Loading

authored by: Khalid Abdel-Rahman, Shuhan Cao, Martin Achmus
Abstract: Steel piles driven into the seabed for offshore structures regularly experience monotonic and cyclic axial loading. The bearing capacity of these piles under cyclic loading degrades with the number of cycles due to the reduction in skin friction. Limited experimental data has led to the development of interaction diagrams, which predict the number of loading cycles until failure based on the mean load and the amplitude of the cyclic load, both often normalized through the static pile bearing capacity. However, these diagrams do not account for varying soil conditions or pile geometries. In this paper, the authors extend the previously developed Capacity Degradation Method (CDM) by incorporating the hypoplastic material law, which accounts for loading and unloading paths, stress levels, and the change of soil void ratios. New interaction diagrams have been developed for different pile geometries. Additionally, the pullout capacities of piles with varying diameters and embedded lengths under different loading cycles are investigated.
Organisation(s): Institute of Geotechnical Engineering
Type: Article
Journal: International Journal of Offshore and Polar Engineering
Volume: 35
Pages: 91-98
No. of pages: 8
ISSN: 1053-5381
Publication date: 03.2025
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Civil and Structural Engineering, Ocean Engineering, Mechanical Engineering
Electronic version(s): https://doi.org/10.17736/ijope.2025.ar03 (Access: Closed)

BibTeX

@article{92dbc911f5a94a86bc06623264bd1056,
title = "Effect of Material Law on the Behavior of Offshore Steel Piles under Cyclic Axial Loading",
abstract = "Steel piles driven into the seabed for offshore structures regularly experience monotonic and cyclic axial loading. The bearing capacity of these piles under cyclic loading degrades with the number of cycles due to the reduction in skin friction. Limited experimental data has led to the development of interaction diagrams, which predict the number of loading cycles until failure based on the mean load and the amplitude of the cyclic load, both often normalized through the static pile bearing capacity. However, these diagrams do not account for varying soil conditions or pile geometries. In this paper, the authors extend the previously developed Capacity Degradation Method (CDM) by incorporating the hypoplastic material law, which accounts for loading and unloading paths, stress levels, and the change of soil void ratios. New interaction diagrams have been developed for different pile geometries. Additionally, the pullout capacities of piles with varying diameters and embedded lengths under different loading cycles are investigated.",
keywords = "Capacity Degradation Method (CDM), cyclic axial loading, hypoplasticity model with intergranular strain, interaction diagrams, Piles",
author = "Khalid Abdel-Rahman and Shuhan Cao and Martin Achmus",
note = "Publisher Copyright: {\textcopyright} 2025, International Society of Offshore and Polar Engineers. All rights reserved.",
year = "2025",
month = mar,
doi = "10.17736/ijope.2025.ar03",
language = "English",
volume = "35",
pages = "91--98",
journal = "International Journal of Offshore and Polar Engineering",
issn = "1053-5381",
publisher = "International Society of Offshore and Polar Engineers",
number = "1",
}