Porosity Evaluation of Coarse Fillings in Single Joint for Artificial Rock Using Electrical Resistivity

The growing importance of developing high-level radioactive waste disposal technologies has led to the increasing use of geological disposal methods. In this regard, nuclides can also be discharged into rivers or oceans through rock fractures. Therefore, monitoring rock fracture characteristics is essential to prevent the leakage of nuclides. Electrical resistivity technology is a useful method for investigating rock fracture characteristics and has been utilized for long-term monitoring. In this study, an electrical resistivity test was performed to evaluate the effects of environmental (temperature and pore fluid resistivity) and geometric (aperture size, filling particle size, and filling porosity) variables of a fracture on electrical resistivity. Based on the results, the correlation between each variable and the electrical resistivity was identified. In addition, the relationship between the porosity of coarse fillings and the electrical resistivity in rock joints was determined, which is expected to be used as basic data to evaluate joint conditions in deep geological repositories when using electrical resistivity monitoring technology. The influence of various factors on the electrical resistivity of rock joints was studied.Environmental and geometric variables were analyzed.The effect of porosity was greater than that of the particle size of fillings.The results help monitor natural barriers of deep geological disposal sites.