Optical measurement of deformation using transparent silica gel to model sand

Abstract

This paper addresses an important and critical need in geotechnical engineering. There are no established methods to measure three-dimensional deformation patterns and flow characteristics within a soil mass. As a result, it is difficult to analyze complex soil-structure interaction and ground flow problems. 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. The fundamental premise of this research is that tests conducted with a transparent material with geotechnical properties similar to those of natural soils can circumvent these experimental problems if the response of a model transparent continuum can be measured using non-intrusive optical visualization techniques. This paper presents the geotechnical properties of a new family of transparent materials made of silica gels, which are suitable for modeling the geotechnical properties of sand. A new imaging technique that makes uses of the developed material in measuring spatial deformations in transparent soil models is also presented.