In this paper, the apparent soil resistivity evaluation is estimated for three layer soils by four strategies and the
obtained values are compared with experimental measurements done by using the four-electrode method. Different
methods are suggested with the aid of IEEE 80 to estimate the apparent soil resistivity of three layer soils in which a
grounding system consists of a grid with rods is constructed. The effect of the reflection factor on the mesh and the step
voltages, the grounding system resistance and the mesh voltage is investigated. It is concluded that the first three methods
are close together and also with the experimental findings done by the authors and others, the fourth method gives some
tolerance with the first three, but it is in agreement with the experimental measurements. It is concluded also that the
reflection factors of non-uniform soil have significant effects on the apparent soil resistivity, the step and the mesh
voltages and the ground resistance. For the verification of the calculated results experimental model is used. It is noticed
that the measured values are slightly high compared with the calculated values; the reason may be is due to the boundary
effects of the used model. |
