Visualization of soil behavior can help us to more intuitively understand phenomenon that occurs in ground. X-ray CT scanner can be the very powerful tool for the visualization. In recent years, the X-ray CT scanning has been applied for not only observation of microscopic soil behavior but also evaluation of macroscopic mechanical response based on adequate image analysis. Accordingly, it is likely that the request to the X-ray CT scanning technics could be higher and higher in near future.
　We, at the Foundations group in the Port and Airport Research Institute, renewed a micro-focus X-ray CT scanner in 2015, instead of the previous one which had been used from 2003 to 2014. In this study, first, we confirmed operation and performance of the renewed X-ray CT scanner.
Furthermore, we attempted two new approaches to geotechnical issues using the X-ray CT scanner. The one was the visualization of model ground. The other was 3D printing of soil structure. For the first approach, we applied some image analyses to the X-ray CT image successfully to visualize and identify the deforming ground area around a coupled-piles which was horizontally loaded. For the second one, using the X-ray CT image of an actual geomaterial, we challenged to duplicate the microscopic particle arrangement of the material by 3D printing. Furthermore, we investigated the macroscopic mechanical response of the 3D printed samples and discussed the applicability of 3D printing for some geotechnical issues. In this study, we successfully duplicated the 3D printed sample, so that it could behave as a granular material. As a result, it concluded that the difference of particle arrangement could affect the macroscopic mechanical response even though the samples had the same packing density.