| Direct shear test is pretty common among geotechnical tests for assessing the strength of granular material. However, due to its setup, it has a few drawbacks, which limits it applicability. Studying its specimens during the test is almost impossible due to the shape of its apparatus. Moreover, the test has a predefined failure surface that reduces the accuracy of its results. Image processing and thin sectioning were employed in this study, to study the evolution of direct shear specimens and some of their characteristics including failure plain and local porosity distribution. The evolution of these features was studied at four stages during a direct shear test. A direct shear test was divided into four sections based on the induced shear displacement. Each of these samples studied using image processing and thin sectioning later. The sample images are used to calculate local porosity at different cross sections of the samples. The calculated local porosities are then used to detect the evolution of shear bands and their length scale features during direct shear tests. The rupture systems are studied in more depth in this study. Their evolution during the four stages was examined in more depth giving a more in depth understanding about patterns, formation and their characteristics.;Keywords: Direct shear test; Thin sectioning; Image Processing; Rupture Patterns; shear localization; shear bands. |
