Identification of Contacts in Volumetric Images of Granular Soils

Abstract

The contacts are critical in granular soils because they control force transmission and therefore the loadbearing capacity of granular soils. In the last decade, the advances of X-ray Computed Tomography (X-ray CT) techniques enabled researchers to capture three-dimensional (3D) volumetric images of soils, in which contacts can be observed. Many researchers have used a 3D image processing technique, called watershed analysis, to identify contacts in 3D volumetric images of soils. However, the watershed analysis cannot discriminate contacting particles and peanut-shaped particles, resulting in oversegmentation of peanut-shaped particles. This research developed an improved watershed analysis to solve this issue. The proposed algorithm was validated using a crushed limestone specimen, which contains many elongated and peanut-shaped particles. The results showed that the improve watershed analysis can accurately identify all the contacts in this challenging soil specimen.