New insights into the failure mechanisms of horizontal plate anchors in clay during pull-out

Abstract

Offshore wind developments are moving towards deep-water regions where energy is abundant, visual impact is minimised and the larger turbine sizes can make the energy production more cost-effective. One of the key challenges facing the industry is the development of reliable substructures. While fixed foundation systems are widely used for shallow-water (,60 m) developments, permanent anchors are seen as one of the most viable mooring solutions for floating structures in deep water. In the current study, the pull-out behaviour of square plate anchors in clay was investigated using large-displacement finite-element analysis. The anchor capacity and failure mechanism were considered for a range of embedment ratios and undrained shear strengths. Three distinct modes of anchor failure identified in previous studies were examined through the analysis of four descriptors including: the pull-out capacity of the anchor, the pull-out displacement required to mobilise this capacity, the energy absorbed by the anchor during pull-out and the variation of the pull-out capacity with respect to a normalised overburden pressure. The findings of the study are presented in the form of a series of charts that can aid design through understanding of the factors controlling the development of anchor failure modes, in addition to identifying the transition point between different failure mechanisms.

An anchoring system for supporting platforms for wind energy devices

“…Proceedings of the Institution of Civil Engineers -Geotechnical Engineering, https://doi.org/10.1680/jgeen.22.00245 clay varied with anchor shape, soil strength and the depth below the seabed, normalised by anchor width (Aubeny, 2019;Das and Seeley, 1975;Giampa et al, 2019;Jalilvand et al, 2022;Lai et al, 2020;Liu et al, 2010Liu et al, , 2012Meyerhof and Adams, 1968;Neubecker and Randolph, 1996;O'Neill et al, 2003;Roy et al, 2021aRoy et al, , 2021bSahoo and Ganesh, 2018;Thorne, 1998;Vesic, 1971: Yu et al, 2015: Zhuang et al, 2022. Novel concepts such as the suction embedded plate anchor (Zook and Keith, 2009), OMNI-Max anchor (Kim and Hossain, 2017), multiline ring anchor (Lee et al, 2021, Lee andAubeny, 2020), fish anchor (Chang et al, 2019, Hossain et al, 2023 and dynamically embedded plate anchor (O'Loughlin et al, 2014) have been developed in recent years.…”

Study of the Indoor Model Test and CEL Simulation of Jacking Force in the Vertical Tunnelling Method

“…Terefore, solving engineering problems by model tests and numerical simulation has become a trend for many scholars to study problems [14]. A coupled Eulerian-Lagrangian (CEL) approach [15] based on an explicit time integration formulation has been widely used for solving large-deformation problems [16][17][18][19].…”