Study on collaborative monitoring of full-section stress and deformation in roadway cable support

In fully mechanized top-coal caving faces, the deformation of surrounding rock and the loading response of anchor cables during roadway excavation are typically assessed through scattered monitoring points rather than coordinated full-section monitoring. This approach complicates the accurate identification of the spatial distribution of stress redistribution, surrounding rock deformation, and support response, particularly under asymmetric mining pressure. To address this issue, this study was conducted at the 826 fully mechanized top-coal caving face in Yuandian No. 1 Coal Mine of Huaibei Mining Group, with the aim of investigating the stress redistribution of surrounding rock and the evolution of roadway deformation near the monitored section during excavation. The research sought to reveal the asymmetric behavior of strata in the excavation roadway and to verify the spatial distribution characteristics and influence range of stress and deformation through numerical simulation. The findings are expected to provide scientific support for monitoring, stability evaluation, and the optimization of support design in excavation roadways under similar geological conditions.

A coordinated field monitoring system was established, integrating a high-precision laser rangefinder, three-dimensional (3D) point-cloud scanning, and anchor-cable stress sensors. This integrated approach enabled the synchronous acquisition of deformation data for the roof, floor, and both ribs, as well as continuous recording of axial-force variations in anchor cables during excavation. The laser rangefinder was used to monitor the convergence and displacement of the roadway profile, whereas 3D point-cloud scanning was employed to reconstruct the overall geometry of the roadway and capture the spatial evolution of deformation along the excavation direction. In addition, anchor-cable stress sensors were installed at critical positions in the support system to measure variations in cable loading at different excavation locations and stages. Based on the field monitoring results, the stress redistribution and deformation evolution of the surrounding rock near the monitored section were analyzed in relation to the excavation distance. A numerical simulation model was also established according to the geological conditions and engineering layout of the 826 face and was then used to simulate variations in anchor-cable force, surrounding rock stress, and rock-mass deformation during excavation and to validate the spatial distribution patterns observed in the field.

Results indicate that during roadway excavation, the stress and deformation of surrounding rock display a pronounced asymmetric distribution pattern characterized by higher values on the working-face side and lower values on the solid-coal side. The strata behavior on the working-face side is significantly stronger than that on the solid-coal side, indicating a clear nonuniform mechanical response during excavation. The axial force in the shoulder anchor cable on the working-face side is significantly greater than that on the solid-coal side, demonstrating that the support structure on the working-face side bears a more concentrated load. The vertical displacement of the roof and floor increases rapidly during the early stages of excavation and then gradually stabilizes as the excavation influence evolves. In addition, the displacement of surrounding rock on the working-face side is notably greater than that on the solid-coal side, further confirming the asymmetric deformation characteristics. The 3D point-cloud scanning results indicate that the roadway can be divided into three zones along its length: a significantly affected zone, an obviously affected zone, and a basically unaffected zone. The deformation of the two ribs also shows a pronounced asymmetric pattern. Numerical simulation results align well with field monitoring data, further validating the spatial distribution of rib loading and deformation as well as the extent of the excavation influence.

This study systematically reveals the asymmetric strata behavior of a roadway excavated in a fully mechanized top-coal caving face. The redistribution of surrounding rock stress, roadway deformation, and the anchor cable loading response all exhibit distinct asymmetry, with the working-face side serving as the dominant control area. The integrated monitoring method, which combines laser ranging, 3D point-cloud scanning, and anchor-cable stress sensing, overcomes the limitations of conventional point-based observation, providing a more comprehensive understanding of full-section deformation and support response. The combined analysis of field monitoring and numerical simulation effectively verifies the spatial characteristics and influence range of asymmetric mining pressure, offering a scientific basis and practical reference for monitoring support effects and optimizing support parameters in excavation roadways under similar conditions.