volume | PIER Journals

Abstract

The coupling of extensive metallic components within utility tunnels significantly complicates the earth-entry and dispersion pathways of cable short-circuit fault currents.This study focuses on a conventional three-compartment utility tunnel to guarantee steady and dependable operation of transmission lines. An integrated grounding system model with a concrete shell, vertical grounding electrodes, and grounding busbar bonding was constructed under various soil-resistivity conditions. The effects of bonding distance, vertical grounding electrode arrangement, and resistivity of the concrete shell on the grounding resistance, ground potential rise, touch voltage, and step voltage were methodically investigated by parametric simulations using CDEGS software. The findings indicate that an appropriate grounding grid spacing can significantly improve the electrical properties of the grounding system, whereas excessive density diminishes these advantages owing to the reciprocal coupling. The incorporation and deepening of the vertical grounding electrodes significantly diminished the ground resistance and ground potential rise. As the resistivity of the concrete shell increased, both the equivalent electrical parameters and surface potential gradient increased markedly. Research has shown that the interaction between the grounding network in utility tunnels and the adjacent soil influences fault-current dispersion pathways. This study provides a reference for optimizing the design of grounding systems for utility tunnels.

1. Chen, Z. L., Z. F. Zhang, and H. F. Wang, "Current status and development trends of urban utility tunnel construction in China," Tunnel Construction, Vol. 45, No. 9, 1615-1626, 2025.
doi:10.3973/j.issn.2096-4498.2025.09.001 Google Scholar

2. Luo, B. C., "An investigation into the integrated construction of urban underground utility tunnels and roadways," Civil Engineering, Vol. 12, No. 2, 107-111, 2023.
doi:10.12677/HJCE.2023.122013 Google Scholar

3. Zhao, X. Y., Y. G. Zhang, J. Z. Hong, et al. "Analysis of 500 kV GIL tube grounding system," Sichuan Electric Power Technology, Vol. 43, No. 2, 59-62, 2020. Google Scholar

4. Pires, C. L., S. I. Nabeta, and J. R. Cardoso, "ICCG method applied to solve DC traction load flow including earthing models," IET Electric Power Applications, Vol. 1, No. 2, 193-198, 2007.
doi:10.1049/iet-epa:20060174 Google Scholar

5. Charalambous, Charalambos A., Ian Cotton, and Pete Aylott, "Modeling for preliminary stray current design assessments: The effect of crosstrack regeneration supply," IEEE Transactions on Power Delivery, Vol. 28, No. 3, 1899-1908, 2013.
doi:10.1109/tpwrd.2013.2259849 Google Scholar

6. Charalambous, Charalambos A. and Pete Aylott, "Dynamic stray current evaluations on cut-and-cover sections of DC metro systems," IEEE Transactions on Vehicular Technology, Vol. 63, No. 8, 3530-3538, 2014.
doi:10.1109/tvt.2014.2304522 Google Scholar

7. Bortels, L., A. Dorochenko, B. Van den Bossche, G. Weyns, and J. Deconinck, "Three-dimensional boundary element method and finite element method simulations applied to stray current interference problems. A unique coupling mechanism that takes the best of both methods," Corrosion, Vol. 63, No. 6, 561-576, 2007.
doi:10.5006/1.3278407 Google Scholar

8. Cerman, Anton, František Janíček, and Milan Kubala, "Resistive-type network model of stray current distribution in railway DC traction system," 2015 16th International Scientific Conference on Electric Power Engineering (EPE), 364-368, Kouty nad Desnou, Czech Republic, 2015.
doi:10.1109/EPE.2015.7161126

9. Ibrahem, Amr, Ali Elrayyah, Yilmaz Sozer, and J. Alexis De Abreu-Garcia, "DC railway system emulator for stray current and touch voltage prediction," IEEE Transactions on Industry Applications, Vol. 53, No. 1, 439-446, 2017.
doi:10.1109/tia.2016.2606367 Google Scholar

10. Zaboli, Aydin, Behrooz Vahidi, Sasan Yousefi, and Mohammad Mahdi Hosseini-Biyouki, "Evaluation and control of stray current in DC-electrified railway systems," IEEE Transactions on Vehicular Technology, Vol. 66, No. 2, 974-980, 2017.
doi:10.1109/tvt.2016.2555485 Google Scholar

11. Jabbehdari, S. and A. Mariscotti, "Distribution of stray current based on 3-dimensional earth model," 2015 International Conference on Electrical Systems for Aircraft, Railway, Ship Propulsion and Road Vehicles (ESARS), 1-6, Aachen, Germany, Mar. 2015.
doi:10.1109/ESARS.2015.7101440

12. Wang, Y. F., "Study on stray current interference range and monitoring method in metro depot," China University of Mining and Technology, China, 2023.
doi:10.27623/d.cnki.gzkyu.2023.000681

13. Yin, S., "Distribution of stray current in urban rail transit depot and the monitoring system design," Urban Mass Transit, Vol. 21, No. 7, 62-65, 2018.
doi:10.16037/j.1007-869x.2018.07.016 Google Scholar

14. Song, D. Z., "Monitoring and control of stray current leakage in metro depot," Urban Mass Transit, Vol. 23, No. 7, 74-78, 2020.
doi:10.16037/j.1007-869x.2020.07.015 Google Scholar

15. Zhu, Feng, Jiacheng Li, Haibo Zeng, and Riqiang Qiu, "Influence of rail-to-ground resistance of urban transit systems on distribution characteristics of stray current," High Voltage Engineering, Vol. 44, No. 8, 2738-2745, 2018.
doi:10.13336/j.1003-6520.hve.20180731034 Google Scholar

16. Zhuang, H. X., F. Xu, W. X. Qian, et al. "Concrete deterioration under coupling condition of stray current and salt-freezing," Journal of the China Railway Society, Vol. 44, No. 1, 143-152, 2022.
doi:10.3969/j.issn.1001-8360.2022.01.019 Google Scholar

17. Song, Baotong, Sihan Wang, Changyuan Xiang, Xiaoyue Chen, and Ju Tang, "Study on the influence of grounding resistance on cable fault overvoltage," Energies, Vol. 18, No. 10, 2601, 2025.
doi:10.3390/en18102601 Google Scholar

18. Li, Botong, Tianfeng Gu, Bin Li, and Yunke Zhang, "Study on the gas-insulated line equivalent model and simplified model," Energies, Vol. 10, No. 7, 901, 2017.
doi:10.3390/en10070901 Google Scholar

19. Tang, L., G. Liu, M. Wu, C. Zhao, X. Xu, and D. Huang, "Influence of GIL tube structure parameters on electrical characteristics of grounding system," Power System Technology, Vol. 43, No. 8, 3032-3038, 2019.
doi:10.13335/j.1000-3673.pst.2018.1868 Google Scholar

20. Fan, R. Q., W. H. Zeng, B. Zou, et al. "Study on grounding characteristics of transmission conduit corridors in challenging terrain," Insulators and Surge Arresters, 2024 (in Chinese). Google Scholar

21. Pan, W. X., T. C. Liu, B. Wang, and D. Min, "Grounding computation method for layered-soil with arbitrary massive texture foundation," Transactions of China Electrotechnical Society, Vol. 31, No. 7, 145-151, 2016.
doi:10.3969/j.issn.1000-6753.2016.07.017 Google Scholar

22. Li, Chengyuan, Xu Chen, Chuan He, Hongjin Li, and Xin Pan, "Alternating current induced corrosion of buried metal pipeline: A review," Journal of Chinese Society For Corrosion and Protection, Vol. 41, No. 2, 139-150, 2021.
doi:10.11902/1005.4537.2019.254 Google Scholar

23. Yang, Y. T., "Research on concrete resistivity and reinforcing concrete steel corrosion rate," Dalian University of Technology, Dalian, China, 2009.

Dr. Shangmao Hu

Dr. Yasong Cao

Professor Wen Cao