Detailed soil investigations to establish a soil reference model and analysis of the influence on the prospective touch voltage by simplifications of the reference model

Abstract:
This paper shows the influence of the soil model simplification on the prospective touch voltage of a simple earthing system, consisting of two half spherical shaped earthing electrodes. The apparent soil resistivity is measured using Wenner’s electrodes array configuration. This data is used to build an approximated soil model with finite cubes by solving this inverse problem. Simplifications of the soil model will be applied to compare the prospective touch voltage of the different models. The results are found by using the means of Finite Element Method (FEM) modelling. It can be seen that, in this case, the best approximation is found by taking the average soil resistivity of each horizontal layer of the reference model to build a layered model.