On the equivalence of uniform and two-layer soils to multilayer soils in the analysis of grounding systems

An extensive study of the equivalence of uniform and two-layer soils to multilayer soils in the analysis of grounding systems has been carried out. Grounding resistances and touch voltages have been computed and compared for different equivalent soil models. The analysis presented shows how to obtain an approximate uniform or two-layer equivalent soil for some multilayer soils. It also shows that a good equivalent soil with respect to ground resistance is not necessarily good with respect to touch voltages. Examples showing the lower and upper bounds of electric responses associated with grounding systems in different equivalent soils are also presented