Evaluation of Pull-Out Capacity of Helical Anchors in Clay Using Finite Element Analysis
Akhil Pandey, Vinay Bhushan Chauhan
Abstract
In the present study, an attempt is made to evaluate the ultimate pullout capacity of the vertical helical plate anchor embedded in clay with a number of geometrical configurations using the limit analysis based on the finite element method. Ultimate pullout capacity (qu) of single and multiple helical plate anchors are determined using numerical analysis considering the two-dimensional axisymmetric model and the stress-controlled loading in the present work. Evaluation of the ultimate pullout capacity of the single helical plate anchor is determined with varying embedded depth (H). Also, the ultimate pullout capacity of multi-plate anchors are evaluated using a detailed parametric study with the consideration of parameters namely numbers of plate (n), spacing between consecutive helical plates (S) while keeping the diameters of the helical plate (D) and anchor shaft (d) constant. The present study underlays the optimum H/D and S/D ratios for single and multiple helical plate anchors, respectively, and establishes a simplified equation for the estimation of qu for a multi-plate helical anchor. Additionally, this study also examines the development of failure surfaces with varying embedded depth for single plate anchor and the interference of failure surfaces in the soil for the multi-helix plate anchors with the variation of S/D ratio.