Two-dimensional Dynamic Image Analysis (DIA) is gaining acceptance in geotechnical engineering research. Three-dimensional (3D) DIA extracts features from 8-12 projections of a particles thus it is believed to verge on the true particle morphology. DIA is fast, efficient, and convenient for characterizing thousands of particles quickly; nevertheless, it captures shapes that are fundamentally different than the 3D morphologies reconstructed using micro-computed tomography (µCT). In DIA particle features are interpreted using external images of a particle, which fail to account for differences in imaging perspectives. In addition, 2D and 3D shape descriptors are influenced by differences in dimensionality projection owing to variations in definition, dimensionality, and perspectives of the particle images employed which causes them to differ from their 3D counterparts. In this study we compared sand particle size and shape descriptors obtained using both DIA and µCT for three natural sands having wide granulometries. 3D DIA offers significant advantages in terms of efficiency, while providing adequate representation of Feret dimensions, Sphericity and Convexity. However, the study demonstrates that 3D Roundness is difficult to characterize using DIA and that shape measurements of complex irregular calcareous sands obtained from 3D DIA are not comparable to those obtained using µCT.
- Computational geometry
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Earth and Planetary Sciences (miscellaneous)