ABSTRACT
A series of tests was carried out to visualize the stresses and strains that occur during penetration of a probe into a granular medium. Since there is no unique relationship between stress and strain in granular material, information about stress-strain behaviour can be obtained only by independent measurement of the stresses and strains in the interior of a sample. Currently, only optical techniques, based on the photoelastic properties of transparent granular material, are available for acquiring field information on stresses and strains. The optical technique has been used to digitize the stress distribution in plane strain models with non-cohesive granular material during penetration of a probe.
