Deep Earthing (Drilling) and Graphite Use for Achieving Ultra-Low Earthing Resistance in Gravelly Soils


Elçi H., Yılmaz M., Hacımustafaoğlu R., Bozdağ A.

Processes, cilt.14, sa.10, ss.1-11, 2026 (SCI-Expanded)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 14 Sayı: 10
  • Basım Tarihi: 2026
  • Doi Numarası: 10.3390/pr14101513
  • Dergi Adı: Processes
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED)
  • Sayfa Sayıları: ss.1-11
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

This study explains how an extremely low electrical earthing resistance was achieved in challenging gravelly soil conditions. In the existing soil, a resistance of 5 ohms was measured using traditional earthing techniques. After excavating and removing the granular soil, it was replaced with fine-grained, sandy-silty clay, then compacted after moistening, reducing earthing resistance to 2.5 ohms. The goal was to achieve a resistance below 0.5 ohms, which is necessary for the precise operation of robotic welding machines. To achieve this, a hybrid strategy was employed, combining deep earthing by drilling with ground-enhancing compounds in the gravelly soil. In İzmir-Torbalı, a 40 m-deep borehole was drilled to install a copper electrode in water-saturated clay below the groundwater level. To increase the conductivity of the granular soil and ensure contact with the electrode, the borehole was filled with graphite powder. As a result, the earthing resistance reached only 0.28 ohms, proving the effectiveness of this method in high-resistance soils.