Displacement in sand under triaxial compression by tracking soil particles on X-ray CT data

The objective of this paper is to obtain displacements in sand in three dimensions under triaxial compression using the results of X-ray CT. A triaxial compression test was conducted on soil called “Yamazuna sand”, which has a wide grain size distribution, and the specimens were subject to CT scanning during the loading process. A large number of CT images, both 2D cross sectional images and also 3D reconstruction images, were obtained from CT scanning. The first objective in this study was to develop a method of tracking soil particles using CT images and then to calculate their movement using this proposed method. The total number of soil particles depended on the relationship between the size of the soil particles and the resolution of the CT apparatus. Finally, the displacement vectors from these movements were calculated in three dimensions under the loading process and the distribution of the localized displacement in the sand was measured. It was confirmed that the combination of the tracking technique with CT images is effective for quantitative discussion on the results of X-ray CT.