Zhang Hailiang, Dong Hui, Hu Dora Juan Juan, Vuong Nhu Khue, Jiang Lianlian, Lim Gen Liang, Ng Jun Hong
Institute for Infocomm Research (I2R), Agency for Science, Technology and Research (A*STAR), Singapore 138632, Singapore.
ST Engineering Urban Solutions Ltd., 6 Ang Mo Kio Electronics Park Road, Singapore 567711, Singapore.
Sensors (Basel). 2024 Sep 20;24(18):6081. doi: 10.3390/s24186081.
Underground telecommunication cables are highly susceptible to damage from excavation activities. Preventing accidental damage to underground telecommunication cables is critical and necessary. In this study, we present field trial results of monitoring excavation activities near underground fiber cables using an intensity-based phase-sensitive optical time-domain reflectometer (φ-OTDR). The reasons for choosing intensity-based φ-OTDR for excavation monitoring are presented and analyzed. The vibration signals generated by four typical individual excavation events, i.e., cutting, hammering, digging, and tamping at five different field trial sites, as well as five different mixed events in the fifth field trial site were investigated. The findings indicate that various types of events can generate vibration signals with different features. Typically, fundamental peak frequencies of cutting, hammering and tamping events ranged from 30 to 40 Hz, 11 to 15 Hz, and 30 to 40 Hz, respectively. Digging events, on the other hand, presented a broadband frequency spectrum without a distinct peak frequency. Moreover, due to differences in environmental conditions, even identical excavation events conducted with the same machine may also generate vibration signals with different characteristics. The diverse field trial results presented offer valuable insights for both research and the practical implementation of excavation monitoring techniques for underground cables.
地下电信电缆极易受到挖掘活动的破坏。防止地下电信电缆受到意外损坏至关重要且很有必要。在本研究中，我们展示了使用基于强度的相敏光时域反射仪（φ-OTDR）监测地下光纤电缆附近挖掘活动的现场试验结果。阐述并分析了选择基于强度的φ-OTDR进行挖掘监测的原因。研究了在五个不同现场试验地点由四种典型的单个挖掘事件（即切割、锤击、挖掘和夯实）以及第五个现场试验地点的五种不同混合事件产生的振动信号。研究结果表明，各类事件能够产生具有不同特征的振动信号。通常，切割、锤击和夯实事件的基波峰值频率分别在30至40赫兹、11至15赫兹以及30至40赫兹范围内。另一方面，挖掘事件呈现出宽带频谱，没有明显峰值频率。此外，由于环境条件的差异即使使用同一台机器进行相同的挖掘事件，也可能产生具有不同特征的振动信号。所展示的多样现场试验结果为地下电缆挖掘监测技术的研究和实际应用提供了有价值的见解。
