Abstract:
In complex environments such as large open-pit coal mines, the coupling performance of different types of optical cables for vibration signals still lacks systematic evaluation. This study aims to provide a scientific basis for optical cable selection in goaf detection in open-pit coal mines by designing and conducting experiments to compare and analyze the performance differences of multiple optical cables under the same detection conditions. A goaf detection test based on Distributed Acoustic Sensing (DAS) is conducted in the Harwusu Open-Pit Coal Mine. Five different types of optical cables are selected to evaluate their detection performance under identical conditions—same area and same vibration source—using multiple geophysical methods. Experimental analysis shows that the GYTXW armored optical cable performs best in terms of active source signal-to-noise ratio (SNR), nighttime self-noise, and daytime background noise coupling in the mining area. The SNR measured by this cable is nearly twice that of the other types. Based on geophysical f-k algorithm analysis, the performance of the five optical cables is evaluated using distributed optical fiber sensing background noise analysis and active source signal analysis in the mining environment. The results confirm that the GYTXW armored optical cable exhibits a higher SNR in active source response and lower background noise compared to the other cables. This study demonstrates that the GYTXW armored optical cable is more suitable for DAS-based detection in complex open-pit coal mine environments. It provides critical guidance for optical cable selection in similar engineering scenarios. These findings have important implications for promoting the application of DAS technology in goaf detection and shallow geological structure imaging in coal mines.