X-ray analysis on the effect of sample preparation on the microstructure of calcareous sands

Abstract

The behavior of a sandy soil in laboratory tests is highly influenced by the sedimentation technique. In this study, a calcareous sand from the reclamation site in Persian Gulf is used as the material to reconstruct laboratory scale samples with the air and water pluviation, moist and dry tamping and dry funnel deposition methods. The microstructure of these calcareous sand samples, including the homogeneity and the spatial consistency of the fabric anisotropy, is examined using X-ray tomography. It is shown that the sample preparation method introduces distinct differences in the sample uniformity and the spatial fabric anisotropy. The sample density varies along the sample height and is highly affected by the boundary effect. The fabric anisotropy is proved to have spatial consistency except for the sample made by the water pluviation method. In the water pluviation sample, the boundary effect on the fabric anisotropy is significant, which is explained by the grain-water interaction during the sedimentation.