Traditional geotechnical engineering is challenged in terms of sustainability, resilience, reliability and resources availability in the context of climate change and urbanization expansion. Abstracting inspiration from nature and adopting to geotechnical engineering, bio-inspired geotechnics can provide innovative solutions to address these challenges. This paper reviews the underlying mechanics of bio-inspired geotechnical engineering from three perspectives, i.e., bio-inspired burrowing strategies and mechanisms, bio-inspired surfaces with textures and bio-inspired underground structures. The results highlight that the bio-inspired burrowing strategies (i.e., particle removal, chiseling/grabbing-pushing, peristalsis, dual-anchor, pivot burrowing, undulatory propulsion, reciprocating, rotation and root growth) differ in their application scopes and burrowing efficacy, and the auxiliary burrowing, the principle of least impendence, as well as the multi-functional root growth presents promising solutions to burrowing challenges. Bio-inspired textured surfaces exhibit performance enhancement with regard to anisotropic friction, wear resistance and actuator initiation. In bio-inspired underground structures, snakeskin- and root-inspired geotechnical elements provide superior performance due to the frictional anisotropy and branching effects, respectively, and the potential implementation techniques are challenging current geotechnical engineering. Finally, transferring issues, potential research trends and future prospects are presented, and the significance of collaborative engagement of both engineers and scientists for promotion in bio-inspired geotechnics is emphasized. (c) 2024 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Deep foundation and anchorage systems are often comprised of simple linear elements, limited by design, materials and techniques employed to build them. Their stability is attained by transferring structural loads to deeper, more stable soil layers across a larger area, reducing potential for excessive settlement and providing resistance against lateral forces from external factors including wind and earthquakes. In comparison, root systems distribute loads to a large volume of soil through a branched morphology of semiflexible elements. Roots also penetrate soil media, reduce erosion, create habitats, and exchange, store and transport resources, while continuously sensing and adapting to environmental conditions. Insights from their integration of multifunctionality can be transferred to civil engineering through biomimicry. As a first step toward designing root-inspired foundations, the effects of various morphological traits (laterals' length, number of nodes, number of laterals, branching angle and laterals' cross section) on foundation performance are evaluated through vertical pullout tests. Out of the model properties, general trends were observed, including the positive correlation between models' surface area and maximum force reached. Yet, due to complex interactions between the model and granular media, no model property fully explained differences in pullout resistance of all models. The effects of each root trait on pullout resistance were analyzed separately, which can serve to adapt the design of root-inspired foundations and exploit granular physics principles. Potential reasons for surprising and counterintuitive results are also presented. Further studies could evaluate the assumptions given as potential explanations of these results by studying identified counterintuitive scenarios.