Abstract:
The deformation and failure of roadway surrounding rocks are key factors limiting the safe and efficient production of coal. Accurate monitoring of roadway surrounding rock deformation and failure is crucial for ensuring the safe extraction of coal resources. However, traditional monitoring techniques struggle to meet the current demands for precise monitoring of roadway surrounding rocks. To explore new methods for monitoring roadway surrounding rocks, this paper focuses on the challenge of precise characterization of the deformation of deep roadway surrounding rocks under mining influence. The paper is conducted in the 1034 working face of the Yangliu Coal Mine in the Huaibei Mining Area, utilizing quasi-distributed Fiber Bragg Grating (FBG) sensing technology to investigate the dynamic deformation characteristics of the surrounding rock in both deep and shallow parts of the roadway during the mining process. The results indicate that there are significant differences in the strain changes measured by optical fibers on the two sides of the return airway. Tensile deformation occurs in the coal side along the horizontal direction, while compression deformation occurs locally on the coal pillar side due to mining influence, with the deformation amount in the coal side being twice that of the coal pillar side. As the working face approaches the monitoring position, the deformation of the roadway surrounding rock becomes more severe. The influence of the advanced support pressure on the deep part of the roadway surrounding rock diminishes, and the strain generated by the surrounding rock decreases accordingly, with the strain peak values concentrated at a depth of 3 to 4 meters. The strain distribution measured by the FBG corresponds to the rock layer’s lithology. In mudstones with lower elastic modulus and softer lithology, the optical fibers experience tensile strain with higher values, while in fine sandstones with higher elastic modulus and hardness, the optical fibers experience compressive strain with lower values. The quasi-distributed FBG sensing technology enables comprehensive monitoring of the deformation process of roadway surrounding rocks during the mining of the working face, providing a basis for the accurate characterization of deep roadway deformation and failure. The findings offer valuable references and insights for subsequent perception of roadway surrounding rock conditions.