An Estimate of the Uncertainty in the Grounding Resistance of Electrodes Buried in Two-Layered Soils with Non-Flat Surface

Abstract

Abstract:The influence of the irregular surface of a multi-layered soil on the estimation of the ground resistance of a complex electrode is studied. The electrode is placed in the first layer while the irregular surface is treated as the interface of an inhomogeneous volume filled with air and embedded in the first layer. A wide sample of irregular soils is generated and the variation of the electrode grounding resistance, as a function of a parameter that measures the surface unevenness, is evaluated. A stochastic model of the grounding resistance is proposed for which the variation of the electrode grounding resistance with its horizontal position relative to the surface is studied. The model features allow us to explain the variability found, as we are able to estimate the part of the uncertainty about the electrode grounding resistance measurements due to the non-planar soil surface.

An Artificial Neural Network Model Based on Experimental Measurements for Estimating the Grounding Resistance

“…Engineers can show the ground profile, the most critical parameter for designing a grounding system and determining the maximum allowable step and touch voltage limits thanks to ground resistivity measurements. In [13], it highlights the importance and necessity for engineers to select appropriate ground resistivity measurement axes in the terrain of interest and correct measurement depths and combinations of axes for the final determination of the earth profile. In this context, it is also proven that appropriate and preplanned measurement of ground resistance, especially in the non-isotropic ground, is of great importance for the precise design of a safe grounding system.…”

Unidimensional Vertical Electrical Soundings involving uneven soil surfaces: improving the apparent resistivity measurements for soil modelling

“…The electrodes buried in the soil acting as current sources are modelled as thin wire electrodes. For a curved thin wire of length L and radius r (L≫r) buried in the ground, the absolute potential at any point is calculated by assuming that there exists a continuous distribution of current points μ(x′, y′, z′) on the wire axis so that (see (9)) .…”

“…in short spacing between the electrodes of the probe, the apparent resistivity measures may contain large errors making it difficult to propose a suitable multilayer model. The influence on the grounding resistance of this type of soil has been initially treated by the authors in [9] where, under certain conditions, a stochastic model is presented to evaluate the uncertainty in the measurement of ground resistance. In this work, the influence of an uneven soil surface on the measurement of apparent resistivity is studied.…”

Electrical Resistivity Measurement with Spherical-Tipped Cylindrical Electrode Embedded on Two Layers

“…Strata have been formed by complex geological processes, including inevitable compositional variations with depth and unpredictable climate change, all of which ultimately lead to variations in pore water chemistry, saturation level, and temperature [4][5][6][7][8]. Previous studies employed (1) the method of image charges using the point electrode that fails to take into account electrode geometries or (2) Bessel function that cannot obtain analytical solution [9][10][11]. However, there is a need to theoretically explore the effects of electrode geometries and multiple layered system on laboratory electrical resistivity measurements.…”