Development of the Method for Locating Preferential Leak Flow Path under Earth Dams By Combining the Salt Tracer with Electrical Self-Potential Measurement

Based on the electrokinetic coupling principle, the salt tracer method combined with self-potential measurement is the solution that allows determining the location of the preferential seepage in earth dams and the water velocity along the flow path. This study focuses on clarifying the relationship between the concentration distribution of the salt tracer in the advection-dispersion process and the anomaly of the potential signal through experiments on physical models. The obtained results showed that the values of the maximum potential variation and the change in salt tracer concentration likely coincide in time and are quite close to water transit time with a retardation of only about 10%. The method was then applied to a seepage area of the study dam in Vietnam. (author)