Development of a Transparent Material to Model the Geotechnical Properties of Soils

Measurement of three-dimensional deformation patterns and flow characteristics within a soil continuum are usually limited by the fact that soil sensors do not provide a continuous image of the measured continuum. Additionally, soil sensors exhibit static and dynamic characteristics that are different from those of the surrounding soils and therefore can change the response of the measured continuum. Tests conducted with a transparent material which has properties that closely model the geotechnical properties of natural soils can potentially circumvent these experimental problems if the response of a model transparent continuum can be measured using nonintrusive optical visualization techniques. This paper demonstrates the feasibility of producing transparent materials which exhibit macroscopic properties representative of the geotechnical properties of natural soils. The transparent "soils" discussed in this paper were made by consolidating suspensions of amorphous silica in liquids with matching optical refractive indices. The measured shear strengths and permeabilities of the transparent soils are characteristic of natural clays and silts. The stress-strain response of transparent soils is characterized by large strains during consolidation and shear.