Pull-Out Behaviour of Square Anchor Plates in Reinforced Soft Clay

Abstract

Anchor plates are generally used for structures like transmission towers, mooring systems, etc. where the uplift and lateral forces are expected to be predominant. The capacity of anchor plate can be increased by increasing the size of the plate, depth of embedment and grouping of anchors. However due to space constraints, it was found that use of geosynthetic can be beneficial in increasing the uplift capacity without altering size of plates. Most of the past research in this area focused on the response of plate anchors in cohesionless type of soil. In the present study it was aimed to determine the uplift capacity of the anchor plates in cohesive type of soils with geosynthetic reinforcement. Numerical simulations were carried out on three different sizes of square anchor plates using general-purpose finite element software ABAQUS. Material non-linearity was considered in the analysis using hypoelastic model. For reinforcement, a single layer geosynthetic was placed at three different positions from the plate. The effects of various parameters such as, embedment ratio, position of reinforcement and width of reinforcement has been studied. Results obtained from the numerical analysis were compared with the previously published experimental results for various conditions. It was also observed that the inclusion of reinforcement results in a shift in overall failure behaviour of plate anchors. Parametric study involving the embedment depth, position of reinforcement in embedded soil indicates the significant role in the behaviour of anchor plates in reinforced soil in terms of ultimate pull-out capacity. The uplift capacity was expressed in terms of dimensionless breakout factor. A formulation for breakout factor has been proposed for different embedment ratio of anchors in reinforced soils.