Transparent amorphous silica to model clay

The fundamental premise of this research is that transparent synthetic materials with geotechnical properties similar to natural soils can be used in model tests to study three-dimensional deformation and flow problems using nonintrusive optical visualization techniques. The transparent "clays" discussed in this paper were made by consolidating suspensions of amorphous silica in a pore fluid with a matching refractive index. Conventional triaxial compression, consolidation, and permeability tests were performed to study the behavior of the material under normally consolidated and overconsolidated conditions. This paper demonstrates the feasibility of producing a family of transparent materials, which can be customized to exhibit shear-strength, pore-pressure, volume-change, and permeability characteristics that are consistent with the behavior of natural clays.