Study on prototype manufacture of inductive magnetic device system to locate the preferential leak flow path through hydrodam

In safety management of hydropower dams and irrigation works, the leakage and seepage processes need to be studied to propose new monitoring methods and techniques for providing sufficient and reliable information on lake and dam leakage, especially when new leaks occur as a basis for safety assessment and subsequent planning. Recently, a new method of approaching the underground preferential flow path has been developed based on the principle that when an electrical potential of identified frequency is imposed on the upstream and downstream of groundwater the alternative electric current will be formed along the flow path. By mapping the inductive magnetic field generated on the surface the location of the underground flow path can be determined by applying the appropriate interpretation techniques. This project was conducted in order to approach the principle of magnetic induction method to develop the methodology and equipment for applying in the dam leakage investigation in Viet Nam and also for integration with the tracer method. The inductive magnetic device system with sensitivity of about 5pT/ Hz has been designed and manufactured. Besides, physical model-based experiments in the laboratory and numerical model based on ANSYS software were carried out to evaluate the proposed method. The field experiments combined with salt tracing was conducted and the results are given and discussed in this repo rt. (author)