This paper presents an experimental and analytical study to investigate the effect of shape on the pull-out capacity of shallow horizontal plate anchors in sand under drained loading conditions. Novel dynamically penetrating plate anchor concepts have been proposed for use in the offshore energy sector. These anchor concepts may have shapes that are atypical, and the analysis of pull-out capacity of these shapes may be needed for design. Most of the research on the capacity of shallow horizontal anchors has focused on square, rectangular or circular shapes. Physical and analytical modelling was used to study the capacity of circular, square, triangular and kite-shaped plate anchors. The 1g physical model results indicated that the circular anchor had the highest capacity, which was up to two times higher than the square anchor, which had the lowest capacity of all shapes included in this study. The equilateral triangle and kite shapes had capacities that fell between the circle and the square shapes. A new generalised non-associated flow limit equilibrium model was developed to predict the pull-out capacity of shallow plate anchors with convex polygon anchor shapes. The model was most accurate at embedment ratios of 4 or less, with a bias of less than 10%.@en

In recent times, interest in dynamically installed foundation systems for deep-sea construction has increased; however, these foundation systems are still under development and need quantification of various soil parameters with different perspectives. For the design of dynamically installed foundations, it is essential to assess the strain-rate effect on very soft soils. The T-bar has been widely used to characterize soft offshore sediments, such as silt and clay, and there is extensive existing literature on the interpretation of test results. Strain-rate dependence has not previously been fully examined for T-bar tests in very soft clay at very high rates of penetration. This paper examines this aspect using a physical model test. A 65-cm-thick kaolin clay bed was formed using vacuum consolidation. A T-bar was driven into the clay bed at rates that varied from 0.1 cm/s to 60 cm/s. The tests revealed that the resistance factor increased by 9 % for every 10-fold increase in the penetration rate for the material tested in this research.

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This paper addresses scaling issues related to small-scale 1-g model tests on plate anchors in sand under drained loading conditions. Previous centrifuge studies from the literature have suggested that the results of conventional 1-g model testing are inaccurate because of scale effects. Other studies have suggested, however, that scaling errors can be reduced in 1-g model tests if the results are presented in dimensionless form and the constitutive response of the model soil is representative of the prototype behavior. There are no experimental studies in the literature that have tested the validity of this approach for plate anchors. A simple 1-g scaling framework was developed for vertically loaded, horizontal plate anchors. Small-scale 1-g model tests were performed on square plate anchors in dry sand, and combined with existing centrifuge and 1-g model test data from the literature to test the scaling approach for both capacity and deformation. The 1-g model tests provided a reasonable representation of the full-scale prototype behavior when the scaling approach was applied.@en