The calculation results of ground potential and electric field based on relative position for vertical 3 layered-soil

The calculation results of ground potentail and electric field for vertical 3 layered-soil, the current sourec is 3000A; the depth of grounding-electrode is 4m; the width of middle soil-layered is 30001m; the resistivity of left soil-layered is 2000Ωm; the resistivity of right soil-layered is 50Ωm; the resistivity of middle soil-layered is 1000Ωm or 20Ωm; the distance between grounding-electrode and observation point maintains 3km,5km and 10km respectively when moveing on of relative position. "A" column indicated the x-coordinate of relative position in two cases, the one is that the midpoint of distance between grounding-electrode and observation point is seen as the x-coordinate of relative position, the other is that the location of grounding-electrode is seen as the x-coordinate of relative position.