The Criterion for Determining the Ultimate Pullout Capacity of Plate Anchors in Clay by Numerical Analysis

Abstract

The Ultimate Pullout Capacity (UPC) is an important index in designing and analyzing plate anchors. However, there are still uncertainties in determining the UPC through the load-displacement curves calculated from numerical analysis. The review on the existing criteria for determining the UPC also demonstrates that there has not been a generally accepted criterion and most existing criteria are not only uncertain but also irrational. Considering that there are still divergences and confusions in determining the UPC and specific studies are rare, further investigations are needed to clarify this basic but important topic before analyzing the UPC and the performance of plate anchors. The present work just emphasizes on the criterion for determining the UPC of plate anchors in clay. After a review of current studies on this topic, the maximum resistance criterion based on large deformation finite element analysis is recommended to determine the UPC of plate anchors, which accords with two rules. The first, a deterministic value of UPC can be obtained by using the criterion. The second, the criterion must be rational which means that it implies clear and right physical meaning and can be generally applied. This criterion is validated firstly by three model tests and then applied to rectangular and circular plate anchors at different embedment depths in both uniform and linear clays to calculate the bearing capacity factors.

A Unified Model for Analyzing Comprehensive Behaviors of Deepwater Anchors

“…The analytical results are examined with the centrifuge model tests of the anchor trajectory in clay by O'Neill and Randolph [47], the model tests on behaviors of anchor in sand by Zhang [48], the model tests and numerical simulation of the pullout capacity of a plate anchor in uniform clay by Singh and Ramaswamy [49] and Liu et al [50], and the centrifuge model tests and numerical simulation of the pullout capacity of plate anchor in linear clay by Chen et al [51] and Liu et al [50], as presented in Figures 11-14. As shown in Figure 11, the predicted results with  = 0.3 show good consistency with the experimental data.…”

Ultimate Pullout Capacity of a Square Plate Anchor in Clay with an Interbedded Stiff Layer

“…Advances in Civil Engineering pullout bearing capacity of the plate anchor does not exceed 10% [5], it is assumed that the steady state has been reached and that the average value of the pullout bearing capacity in this steady state is the net ultimate pullout bearing capacity Q n of the plate anchor. e pullout bearing capacity coefficient N c of the plate anchor can be obtained by formula (1) [5].…”

“…Wang et al [3,4] investigated the influences of the plate anchor shapes and the separation mode of the interface on the uplift bearing characteristics of plate anchors using the three-dimensional large deformation RITSS technique. Liu et al [5] used the CEL technique (a fluid-solid coupling algorithm) in ABA-QUS to analyze the large deformation of soils, and the variation rules of the complete load-displacement curves of plate anchors with different embedment depths and sizes were discussed. Athani et al [6] and Evans and Zhang [7] analyzed the behavior of plate anchors during pullout in a granular assembly using the discrete element method, and the microscale physical processes were elucidated.…”

Offshore Geotechnical Problems in Deepwater Mooring Techniques for Large Floating Structures

“…There has not been a generally accepted criterion for determining the UPC and most existing criteria are not only uncertain but also irrational. Presently, the maximum resistance criterion based on the large deformation FE analysis is adopted to determine the UPC (Wang et al, 2010a;Liu et al, 2014b), which overcomes the shortages of other existing criteria. The pullout capacity of anchors subjected to long-term cyclic loading relates directly to the cyclic behavior of soils and is still a great concern of researchers.…”