Analysis of Grounding Systems in Horizontal Multilayer Soils Containing Finite Heterogeneities

This paper presents a theoretical model for the analysis of grounding systems located in multilayer soils in which arbitrary heterogeneities (finite volumes) are embedded. The presence of the heterogeneities is handled through a boundary element method, whereas that of the horizontal soil layers is analytically handled using image theory (or any other equivalent technique). Numerical results are presented for several cases and are shown to agree with limiting cases. The results also clearly show that the presence of finite heterogeneities in multilayer soils can have a very strong impact on the safety performance of a grounding system.