Hamdy A. Ziedan’s research while affiliated with Assiut University and other places

Among the important influences on grounding systems are soil resistivities, as well as climatic changes such as temperature and humidity. Previous scientific research in soil enhancement materials is constantly improving to reduce soil resistance, and then improve the grounding systems to ensure safety of people and public facilities against the risks of fault current leakage or lightning strike. This paper presents a review based on the scientific analysis of previous research in field of soil-enhancement materials and their types under the influence of low and transient (impulse) testing conditions. The traditional and recent soil-enhancement materials are rearranged and divided into three main categories (natural, chemical, and waste) according to their nature. Then, it will focus on methodology, field, and computational methods of measurement. In addition, the soil-enhancement materials evaluation in grounding system based on their advantages and drawbacks is reported.

The grounding scheme is one of the main elements for protection system to mitigate the effect of unwanted lightning strikes or operational failures due to faults in generation, transmission and distribution systems. Desert sand soil has a very low electric conductivity, causing weakness in grounding system. To mitigate problems, the soil is supported with a high conductivity agent to adjust the soil conductivity to acceptable levels. A high-cost and non-renewable commercial product can be added to soils to increase their conductivity. This study brings innovation to conventional soil-enhancement materials. A newly developed mixture is proposed, which is composed of waste-activated carbon received from water purification industries and wood ash from agricultural wastes. First, mixture samples with different compositions of available waste materials were prepared. Then, experimental tests were performed and optimized with a combined genetic algorithm (GA) and fuzzy ranking method to estimate the optimal percentage volume value of each material involved in the developed mixture. To validate the effectiveness of the developed mixture, the results were compared with a commercial product available in the market. Also, the obtained results using GA are compared with those obtained by particle swarm optimization (PSO) to appreciate the best GA solutions. The effectiveness of using the developed mixture and the commercial product in reducing the resistance-to-ground of a rod driven in high and low resistivity soils is evaluated. Finally, a sample of the developed mixture was checked to be non-corrosive material for copper grounding rods.