Evaluation of the Pullout Behavior of a Self-Flip Anchor Installed in a Sandbox

Soil or ground anchors are lightweight foundation systems designed to resist uplift or rotational forces acting on a structure. The percussion-driven earth anchor (PDEA) is a self-flipping anchor that can be efficiently installed in various ground conditions using conventional construction equipment. This study presents the results of laboratory pullout tests conducted on PDEA anchors embedded in a soil box filled with poorly graded sand with gravel (SP). The box, measuring 100 cm in length, 90 cm in height, and 36 cm in width, was equipped with a flip-enabled anchor connected to a wired tendon and subjected to a vertical monotonic pullout using a manual hoist. Digital image correlation (DIC) and close-range photogrammetry were employed to analyze soil-anchor interaction mechanisms. The influence of embedment depth, anchor size, installation orientation, and soil compaction on the pullout capacity of PDEA anchors was investigated. Load distribution was obtained from DIC analyses, and limit equilibrium analysis was used to verify the maximum measured pullout loads. The formation of wedge-shaped failure mechanisms and the inclination of slip surfaces during the pullout process were revealed through DIC observations. The results indicated that PDEA anchors exhibited slightly lower capacities compared to equivalent plate anchors.