Fundamental research for transport-diffusion of contaminants in the basement

这是弄清污染物在地下室中迁移扩散现象的基础性研究。本研究的特点是利用工业用X射线CT作为非破坏性可视化技术，对可视化的建立和输运扩散现象的评价方法进行了研究。本项目取得的成果如下：1）领先于世界建立了可视化传输扩散现象的示踪X射线CT方法。这种粘度与密度无关的新型示踪剂使岩石和土壤中的输运扩散场清晰可见。利用示踪剂X射线CT方法获得的图像数据，建立了分析输运扩散过程中速度结构的理论。2）建立了示踪剂X射线CT图像可视化的基本实验技术 关于我们 提出了用示踪X射线CT法分析速度结构的方法。开发了新的图像处理技术，建立了确定扩散长度等与输运扩散相关的物理参数的实验评价方法。3）为了从X射线CT图像数据中评价孔隙的空间分布，阐明了克里金法的适用性。本文还应用示踪剂X射线CT方法对完全饱和的多孔砂岩和孔隙度为10 ~ 60%的人工多孔材料进行了岩石中输运-扩散的结构依赖性分析。这些结果为进一步研究输运-扩散现象提供了有用的数据。4）开发了能考虑材料非均匀性和各向同性的二维输运-扩散有限元程序，并通过数值分析验证了示踪X射线CT方法的有效性。这些结果为示踪X射线CT法速度结构分析的误差评估提供了必要的基础数据。少

This is the fundamental studies to make clear the transport-diffusion phenomena of contaminants in the basement. The characteristic point of this study is to utilize X-ray CT for industrial use is applied as a nondestructive visualization technique, and the establishment of the visualization and the evaluation method of the transport-diffusion phenomena have been investigated.Studies have been conducted according to the following 4 subjects. The results obtained in this project are follows.1)The tracer X-ray CT method to visualize transport-diffusion phenomena was established ahead of the world. That is, the new tracer, which viscosity is independent from the density, makes possible the clear visualization of the transport-diffusion field both in rocks and soils. Utilizing the obtained image data by the tracer X-ray CT method, the theory to analyze the velocity structure during transport-diffusion was also established.2)The fundamental experimental technique for the visualization of tr … More ansport-diffusion field and the method to analyze velocity structure by tracer X-ray CT method was developed. The new image processing technique was also developed, and the experimental evaluation method to determine physical parameters related to transport-diffusion, such as diffusion length, was established.3)In order to evaluate space distribution of pores from X-ray CT image data, applicability of kriging method was clarified. The structure dependency of transport-diffusion in a rock was also analyzed by applying the tracer X-ray CT method towards fully saturated porous sandstone and artificial porous materials which has 10 to 60% porosity. These results provided useful data to future studies of transportation-diffusion phenomena.4)2-D transport-diffusion FEM code which can consider the heterogeneity and the isotropy of materials was developed, and validity of the tracer X-ray CT method was confirmed by numerical analyses. These results provided fundamental necessary data to the error evaluation in the analysis of velocity structure based on the tracer X-ray CT method. Less