| The intrinsic properties and fabric anisotropy of sands significantly affect their macroscopic engineering behavior including packing densities, compressibility and strength. However, due to difficulties in reliably and rapidly determining them, intrinsic properties such as gradation, particle roundness and sphericity as well as the related fabric anisotropy of soils have not received their deserved attention and usage in practice. This dissertation introduces research that has facilitated rapid and precise quantification of soil properties and fabric anisotropy using various newly developed image analysis techniques. Extensive laboratory tests were performed on sands of various gradations, roundnesses, sphericities and geologic origins to develop relationships between their intrinsic properties and macroscopic mechanical behavior. A gradation-shape-fabric based Distinct Element Modeling technique was developed to simulate the properties and fabric anisotropy of soils. Besides geotechnical engineering, the technique can be used by engineers and scientists in various disciplines including material science, geology, mining, powder sciences, pavement engineering and agriculture to simulate more realistic material particle geometries and microstructures. |
