Electromagnetic environment monitoring and analysis of utility tunnels in Xiamen

Abstract

To study the distribution characteristics of the overall electromagnetic environment in the main working areas of an underground utility tunnel, a set of process and monitoring methods for the electromagnetic environment layout of the underground utility tunnel was established by referring to relevant standards. The electromagnetic environment of five underground utility tunnels in Xiamen was monitored using the above-mentioned method from 2017 to 2019. The power frequency electric field intensity range is 0.084~4.995 V/m, and the power frequency magnetic induction intensity is 0.026~21.069 μT. The overall electromagnetic environment of the utility tunnels meets the national requirements and is much lower than the specified national limits of electromagnetic radiation exposure (a power frequency electric field strength at 50 Hz frequency is less than 4 000 V/m, and the power frequency magnetic induction strength is less than 100 μT). There is no significant difference between months in the overall electromagnetic environment of utility tunnel. However, in the underground utility tunnel of Jimei Avenue in Xiamen, where 110 kV transmission line is connected and the outer material is slightly damaged, the power frequency electromagnetic field intensity is significantly higher than that of the ordinary monitoring points, and there is no significant difference between the power frequency magnetic induction intensity and the ordinary monitoring points. The electromagnetic environment of underground utility tunnels in Xiamen is safe for employees. Compared with overhead 110 kV transmission lines, it has less impact on the surrounding electromagnetic environment.

Keywords

• utility tunnel
• electromagnetic environment monitoring
• electromagnetic radiation
• radiofrequency radiation