The Pullout Behaviour Of Plate Anchors In Sand Under Inclined Loading

From last three decades,offshore energy programs and other development systems extend to deeper waters.Floating facilities generally replace the conventional platforms.More than 50%of renewable energy development systems,such as wind energy,are likely to be in deep water which need floating platforms moored by anchor.The soils at the seabed often consist of sandy soil strata;therefore,offshore structures need anchor systems such as suction caissons,piles and direct embedment of anchor plates.Plate anchors are very suitable for different soil conditions and attractive due to their light weight,high efficiency,compact size and various installation techniques.For securely design of mooring system,more reliable models are required to investigate anchor plate performance in sandy soilsPrevious research on plate anchor has focused on either horizontal or vertical anchors.A limited research focused on inclined plate anchor performance in cohesionless soil,particularly for inclined square plate anchors,has triggered a strong motivation for this research.Therefore,extensive large deformation finite element simulations were performed to investigate the effects of width,embedment depth and inclination angle from a shallow to a deep embedment to evaluate the anchor performance.Coupled Eulerian Lagrangian technique applied to investigate the pullout capacity of plate anchors embedded in sand.Mohr Coulomb model adopted in present research which is based on elastic-perfectly plastic.The computational studies show that breakout factors for 1 m wide horizontal square and strip anchors increase with anchor embedment ratio.Breakout factors produced by finite element analysis software with Coupled Eulerian Lagrangian method,compare reasonably well with established limit state and finite element-based theories.Large deformation finite element analyses were performed to investigate the performance of inclined square and strip plate anchors embedded in cohesionless soil with various inclination angles ranging from 0°to 90°by using Coupled Eulerian Lagrangian technique of finite element analysis software.The study predictions showed a significant sensitivity of breakout factor to the anchor width.Accordingly,the width effect to the design of the anchor plates in cohesionless soil should be given careful consideration,especially for vertical anchors with large embedment depth ratios.For design purposes,a relationship was proposed to determine the breakout factor of an inclined anchor at any inclination angle between 0°and 90°.