Application of Earthing Backfill Materials in Desert Soil Conditions

This paper presents trial field investigations and analysis of experimental data of applying of backfill materials in specific arid terrain prevalent in the Middle East. The analyses are based on extensive measurements on sites at five typical locations over a one-year period. At each location, the Wenner four-pin method measurements were performed. Each of the five test sites contained 11 grounding systems, ten of them being applicable in practice, where the loops are buried at the depth of 0.6 m. Based on these extensive measurements and performed calculations supposing perfect contact between grounding electrodes and the soil, the contact resistance between the electrode and the soil is analyzed and evaluated for each of the tested grounding systems. This paper also discusses measured and calculated (using finite elements methods) distributions of surface potential (influencing touch and step voltages). As an important issue in engineering process (measurements according to the Wenner method and technique of interpretation of the measuring results), high resistivity of soil near surface and its nonuniformity are discussed. Considering these technical parameters and the economic aspects, the final recommendation of applying backfill materials (position, size, and type) in specific difficult soil conditions such as prevailing in the Middle East is given in this paper.