Numerical analysis of a class of foundation grounding systems surrounded by two-layer soil

The general theoretical method for determination of the electrical properties of complex substation grounding systems embedded in nonuniform soil is adjusted and applied to the practical case of a foundation grounding system surrounded by two-layer soil. The proposed method appears to be considerably more accurate than the only alternative method found to deal with the same problem. A simple approximate formula for a practical assessment of the grounding resistance of such a grounding system is given.<>