Visualization of thermal fluid flow in rock sample by X-ray Computed Tomography

x射线计算机层析成像成功地用于可视化地质体内部的流体流动。为了设计和制作高温热流体流动实验装置，在岩土材料和流体保持恒温的条件下进行了一系列基础实验。因此，一套可用于高温实验的技术链连同解释实验结果的理论一起发展起来。成功地将序列图像相减和局部区域平均技术应用于流体的孔隙结构、含水率和浓度的定量分析，并提出了改进的软件，用于热流体流动分析所需的多孔介质中流体迁移、渗透系数、扩散系数和分散度前土体应变局部化的图像处理。在流体流动实验方面，通过对一维水流实验得到的连续投影进行减法，提出了一种新的方法，即多步加压过程和沿水面矩阵吸力的大小。此外，本文还提出了一种新的一维方法，可用于在恒定流速下定量测定多孔介质中的溶质，并以碘化钾溶液为示踪剂进行了成功的实例研究。从目前的研究结果来看，x射线计算机断层扫描技术是目前有望用于岩土力学模型实验和岩土内部流体流动现象定量分析的一种监测工具。

X-ray Computed Tomohraphy was successfully utilized for the visualization of fluid flow within geo-materials. In order to design and produce the apparatus for a thermal fluid flow experiment at a high temperature, a series of fundamental experiment was performed by maintaining geo-materials and fluid at constant temperature. Consequently, a chain of technique available for a high temperature experiment was developed together with the theory for interpriting the experimental results.Namely the subtraction of serial images and the local region avaraging technique were successfully applied to the quantitative analysis of porosity structure, water ratio and concentration of fluid, and the improved sofyware was presented for image processing of the fluid migration in porous media, the strain localization in soil prior to the coefficient of permeability, the diffusion coefficient and the ispersivity required for the thermal fluid flow analysis.As concerns the fluid flow experiment, a new method called multi-step pressurization procedure has been presented together with the magnitude of the matrix suction along water front, from the subtraction of serial projections obtained by one-demensional water flow experiment. Moreover, a new one-demensional method available for the quantitative solute within porous media at constant flow rate was developed, and a successful case study was presented using the solution of potassium iodide as a tracer.From the present stydty, it is concluded that the X-ray Computed Tomography is a hopeful monitoring tool presently available for geomechanical model experiment and the quantitative analysis of fluid flow phenmena within rock and soil.