Behaviour of Offshore Steel Piles under Cyclic Axial Loading using CDM with Hypoplasticity

authored by: Khalid Abdel-Rahman, Shuhan Cao, Martin Achmus
Abstract: The driven steel piles used as foundations for the offshore structures are often subjected not only to monotonic but also to cyclic axial loading. The pile capacity under cyclic loading decreases with number of loading cycles due to the reduction of pile skin friction. From the limited number of tests available, interaction diagrams have been developed, which give the number of load cycles leading to failure dependent on the mean load and the amplitude of the cyclic load portion, both related to the static pile capacity. However, such diagrams cannot account for different soil conditions or pile geometry. In this paper, the method “Capacity Degradation Method (CDM)” developed by the authors was extended using the Hypoplastic material law, which considers the effect of loading and unloading path, stress level and the soil void ratio. Based on different pile geometries, new interaction diagrams have been developed. The pullout capacity of piles with different pile diameter and embedded lengths under different loading cycles are also presented.
Organisation(s): Institute of Geotechnical Engineering
Type: Conference contribution
Pages: 1183-1190
No. of pages: 8
Publication date: 2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Energy Engineering and Power Technology, Ocean Engineering, Mechanical Engineering

BibTeX

@inproceedings{6a36f02e0a0442ff94c627a0ac1bad93,
title = "Behaviour of Offshore Steel Piles under Cyclic Axial Loading using CDM with Hypoplasticity",
abstract = "The driven steel piles used as foundations for the offshore structures are often subjected not only to monotonic but also to cyclic axial loading. The pile capacity under cyclic loading decreases with number of loading cycles due to the reduction of pile skin friction. From the limited number of tests available, interaction diagrams have been developed, which give the number of load cycles leading to failure dependent on the mean load and the amplitude of the cyclic load portion, both related to the static pile capacity. However, such diagrams cannot account for different soil conditions or pile geometry. In this paper, the method “Capacity Degradation Method (CDM)” developed by the authors was extended using the Hypoplastic material law, which considers the effect of loading and unloading path, stress level and the soil void ratio. Based on different pile geometries, new interaction diagrams have been developed. The pullout capacity of piles with different pile diameter and embedded lengths under different loading cycles are also presented.",
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} 2024 by the International Society of Offshore and Polar Engineers (ISOPE).; 34th International Ocean and Polar Engineering Conference, ISOPE 2024 ; Conference date: 16-06-2024 Through 21-06-2024",
year = "2024",
language = "English",
isbn = "9781880653784",
series = "Proceedings of the International Offshore and Polar Engineering Conference",
publisher = "International Society of Offshore and Polar Engineers",
pages = "1183--1190",
booktitle = "Proceedings of the 34th International Ocean and Polar Engineering Conference, 2024",
address = "United States",
}