Bioinspiration for Anisotropic Load Transfer at Soil–Structure Interfaces

Abstract

Load transfer across soil–structure interfaces plays an important role in the capacity and efficiency of many geotechnical applications. Some geotechnical applications may benefit from soil–structure interfaces that mobilize different amounts of shear resistances depending on the direction of loading. Bioinspiration is used in this study to develop a series of surfaces modeled after the ventral scales of different snake species that exhibit anisotropic interface shear behavior. The frictional behavior of the snakeskin-inspired surfaces was assessed by means of interface shear box tests on sand specimens composed of two different sands. The results indicate a prevalent anisotropic behavior, where shearing in the cranial direction (i.e., against the scales) mobilized larger peak and residual interface strength and dilation than shearing in the caudal direction (i.e., along the scales). A parametric study on the geometrical characteristics of the scales revealed the isolated effect of their height and length, and particle image velocimetry analyses revealed larger soil deformations and dilation induced within the soil during cranial shearing. The scale geometry ratio is shown to qualitatively capture the interface load-transfer mechanisms between the sand and different bioinspired surfaces.