Toward Enhancing Soil Resistivity Measurement and Modelling for Limited Interelectrode Spacing

This article explores the influence of the maximum interelectrode spacing in soil resistivity measurements on the 1-D soil modeling process. Soil equivalent models are generated based on actual measurements using a Wenner configuration. The results indicate that soil resistivity models are significantly impacted by the maximum interelectrode spacing. For short spacings, rms errors ranging from over 19% to approximately 26% are observed, leading to up to a 5% reduction in upper layer resistivity and a 45% difference in the lower layer resistivity. To address this issue, a practical solution is proposed to improve the measurement and modeling process for sites with limited interelectrode spacing. The viability and rationale behind this solution are discussed and verified using extensive additional measurements. The verification process yielded positive results, confirming the potential of the proposed method for two-layer soils, as considerable improvement in the soil model was achieved. To cover additional scenarios and simulate measurements at different locations, synthetic data based on theoretical expressions are also considered. The synthetic data provided further evidence of the effectiveness of the proposed solution, but also highlights the need for further investigations to generalize the method for soils with a greater number of layers.