Experimental and analytical stability of thick origami panels for deployable anchors to prevent coastal erosion

Underground anchors are often large and heavy due to being over-designed, and this results in expensive transportation costs that consume significant amounts of fuel. Underground deployable anchors offer materially efficient alternatives that can address the growing challenge of slope instability in coastal areas exacerbated by shifting climates. A novel design for deployable ground anchors consists of a pile with deployable attachments, referred to as awns. This design uses less material to achieve an equivalent surface area when compared to cylindrical piles. The installation process for deployable ground anchors is torque-driven, like that of drilled shafts, rather than using impact or vibration hammers. This paper presents an experimental methodology to determine the increase in the shear plane in sandy soil using deployable underground anchors. Ink dots were placed on the bottom of a test box, where a document camera captured the movement of the ink dots, and an ink tracking technique was employed to locate the shear plane. In addition to experimentally assessing the performance of the ground anchors, a computational analysis is completed by creating an equivalent bar and hinge model of the awns, considering both in-plane and out-of-plane loading scenarios. The findings of this study are that the ink tracking technique in sandy soil is useful for experimentally determining the shear plane effects of deployable awns from the ground anchor, and that the bar cross-section optimization adequately represents the behavior of thick origami as it pertains to the deployable awns under in-plane and out-of-plane loading. These insights are significant advancements for understanding the optimal design and functionality of deployable ground anchors.