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<p>Thick-hard roof instability is a major source of dynamic pressure hazards in underground coal mining. This study investigated the instability mechanism and control of thick-hard roof caving at the 1014 mining face of Yushuquan Coal Mine, Xinjiang, China. A physical similarity model was established to simulate mining-induced roof failure, and overburden deformation, mining-induced stress, and acoustic emission (AE) activity were monitored throughout excavation. The results showed that roof caving developed as a discontinuous dynamic instability process characterized by local initiation, upward fracture propagation, sudden large-scale collapse, and subsequent re-stabilization. As the mining face advanced, an arch-shaped stress concentration shell formed above the goaf and evolved with overburden load redistribution. The formation, migration, dissipation, and reconstruction of this shell controlled periodic roof caving and stress mutation. Before roof collapse, AE events increased markedly along the caving boundary, indicating progressive microcrack coalescence. Collapse was accompanied by an abrupt stress drop and a sharp increase in AE activity, suggesting rapid energy release and providing potential precursor information for roof instability. Based on this mechanism, a three-stage blasting strategy was proposed, including directional pre-splitting, fan-shaped loosening blasting, and deep-hole weakening. Field application showed that the caving block size decreased by more than 50%, the suspended roof distance decreased from 16 m to 9 m, roof subsidence and coal seam deformation decreased by 40.2% and 51.7%, respectively, and hydraulic support peak pressure decreased by 8.0%–8.8%. These findings indicate that the proposed method can regulate stress transfer, promote controlled roof caving, and improve thick-hard roof stability under the studied geological conditions.</p>

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Stress field evolution and control measures for thick-hard roof instability induced by mining disturbance

  • 期刊论文

  • 发表日期：

    2026年7月29日

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  • Zhibiao Guo,
  • Lili Xie,
  • Jinglin You,
  • Yuanxin Zhao,
  • Yiming Qi

摘要

Thick-hard roof instability is a major source of dynamic pressure hazards in underground coal mining. This study investigated the instability mechanism and control of thick-hard roof caving at the 1014 mining face of Yushuquan Coal Mine, Xinjiang, China. A physical similarity model was established to simulate mining-induced roof failure, and overburden deformation, mining-induced stress, and acoustic emission (AE) activity were monitored throughout excavation. The results showed that roof caving developed as a discontinuous dynamic instability process characterized by local initiation, upward fracture propagation, sudden large-scale collapse, and subsequent re-stabilization. As the mining face advanced, an arch-shaped stress concentration shell formed above the goaf and evolved with overburden load redistribution. The formation, migration, dissipation, and reconstruction of this shell controlled periodic roof caving and stress mutation. Before roof collapse, AE events increased markedly along the caving boundary, indicating progressive microcrack coalescence. Collapse was accompanied by an abrupt stress drop and a sharp increase in AE activity, suggesting rapid energy release and providing potential precursor information for roof instability. Based on this mechanism, a three-stage blasting strategy was proposed, including directional pre-splitting, fan-shaped loosening blasting, and deep-hole weakening. Field application showed that the caving block size decreased by more than 50%, the suspended roof distance decreased from 16 m to 9 m, roof subsidence and coal seam deformation decreased by 40.2% and 51.7%, respectively, and hydraulic support peak pressure decreased by 8.0%–8.8%. These findings indicate that the proposed method can regulate stress transfer, promote controlled roof caving, and improve thick-hard roof stability under the studied geological conditions.