Decreasing Electric Field in Soil Near Grounding Device by Building an Underground Insulating Wall

It is necessary to restrain the electric field near some civic facilities in the earth, such as gas pipes, communication cables, and so on, if a grounding device is buried nearby. This paper proposed an approach to restrain the electric field by building an underground insulating wall between the grounding device and the facilities. The leakage current from the grounding device can be forced to bypass the wall to reduce the electric field and the ground potential rise behind the wall. The electric-field distribution was simulated by using a numerical approach, coupling method of moments with a boundary-element method. The effectiveness of the proposed approach and the accuracy of the numerical simulation were verified by the field test on a real built insulating wall. The effects of the insulating wall on the electric field, the ground potential rise, and the step voltage nearby were discussed.