Soil structure effects grounding systems designed to guarantee
safe operation of electric power systems. This work investigated
effects of the presence of two/three vertical adjacent mediums
on measured apparent soil resistivity. The Wenner method was
used to measure the apparent soil resistivity in the vertical-layer
soil. Different vertical-layer soils were studied, such as two-verticallayer
soil, three-parallel-vertical-layer soil, and three-perpendicularvertical-
layer soil. Numerical models were used to model the four
electrodes at different vertical-layer soil by using the current source
simulation method. The measured apparent soil resistivities at different
vertical-layer soils were compared with the apparent soil resistivity
at a uniform-layer soil. Results show that the apparent soil
resistivity was affected by the presence of vertical-layer/s soil. Different
parameters affected the measured apparent soil resistivity, such
as measuring angle slope with vertical layer, distance between measuring
electrodes, and distance between measuring electrodes and
interface between the vertical-layer soil.