Manufacture of Bonded Granular Soil Using X-Ray CT Scanning and 3D Printing

This paper describes the use of X-ray tomography imaging of natural gravel specimens to create repeatable assemblages of bonded gravel-size resin specimens using a 3D printer. The paper describes how the resulting resin-based surrogate specimens have particle geometry and interparticle bonds that are a function of the original scanning image resolution and 3D printer resolution. Results of conventional triaxial compression testing of original source gravel specimens and constructed bonded specimens are compared. While there are quantitative differences in behavior between unbonded source and bonded duplicate specimens, the surrogate specimens are shown to have macroscale mechanical behavior that may be considered typical of some granular soils. The ability to generate identical surrogate bonded granular specimens with the same particle arrangement holds promise to remove the influence on geotechnical laboratory testing outcomes due to the unavoidable structural variation in specimens of natural granular assemblages.