Influences of water and oil two-phase on electrical resistivity of oil-contaminated soils

In order to study the electrical resistivity of oil-contaminated soils, the diesel-contaminated soils and kerosene-contaminated soils with different water contents, oil contents are mixed in the laboratory by hand. The four electrode method is used to measure the electrical resistivity of these soils. The results show that two types of oil-contaminated soils have following similar trends: under the same water content, the resistivity of both contaminated soils increases linearly with the increase of oil content; while under the same oil content, the resistivity of these soils decreases in power function with the increase of water content and water saturation degree. In addition, two indexes of volume moisture content, water and oil saturation degree are introduced here to study the influences of water and oil two-phase on the resistivity of oil-contaminated soils. Under the same water saturation degree, it is found that the resistivity of contaminated soils increases linearly with the increase of volume moisture content; while under the same volume moisture content, the resistivity of which decreases in power function with the increase of water and oil saturation degree. Furthermore, a linear relationship between the resistivity and the volume moisture content as well as a power function relationship between the resistivity and the water and oil saturation degree of these soils is observed. For both types of oil-contaminated soils, they can be calculated by the same formula.