Optical measurement of sand deformation around an uplifting deep anchor using digital image correlation method

This report presents a study on the soil deformation around an uplifting deep circular anchor in sand. A scaled model anchor test setup, including a loading frame, a Plexiglas mould, a camera, and a computer, was developed and a series of scaled model test were performed in order to investigate the mechanical behavior and failure modes of a deep anchor embedded in sand. To find the displacement field the digital image correlation (DIC) method was applied. A set of images were captured while a semi-circular anchor was uplifted against the Plexiglas window, and soil displacement field was calculated by comparing any two consecutive images using DIC method. The study shows that the density of soil has a significant effect on both the deformation characteristics and the failure mechanism of the anchor. While in loose sand the failure zone is a compressed bell shape, in dense sand the failure zone is a truncated cone extending from the anchor edge to the surface of the soil. Furthermore, in dense sand the anchor experiences smaller displacement before reaching to the peak pullout force compared to a larger displacement in loose sand. This report has been done by Pezhman Sainia for the M.Eng degree's research project final report with the supervision of Dr. Jinyuan Liu.