Modelling capacity of transparent soil

Abstract

The modelling capacity of transparent soil was investigated by comparing boundary soil displacement fields under a model footing in a transparent soil model with those from a natural soil model. Transparent soil is made of either amorphous silica gels or powders and a pore fluid with a matching refractive index to model sand and clay. An optical system consisting of a laser light, camera, frame grabber, and computer was developed to optically slice a transparent soil model. A distinctive laser speckle pattern was generated by the interaction between the laser light and transparent soil. Two laser speckle images before and after a deformation were used to calculate the displacement field using an image processing technique called digital image correlation. The comparative study shows that transparent soil can be used to study natural soil with some limitations. Transparent soil and the developed optical system could be used to explore opportunities for more advanced nonintrusive three-dimensional deformation measurements for various soil–structure interaction problems.