TAN Yunliang,ZHANG Xiufeng,FAN Deyuan,et al. Mechanism and practice of structural modification to lateral overlying strata in gob-side entry for rockburst prevention[J]. Journal of China Coal Society,2025,50(1):209−223. DOI: 10.13225/j.cnki.jccs.2024.1565
Citation: TAN Yunliang,ZHANG Xiufeng,FAN Deyuan,et al. Mechanism and practice of structural modification to lateral overlying strata in gob-side entry for rockburst prevention[J]. Journal of China Coal Society,2025,50(1):209−223. DOI: 10.13225/j.cnki.jccs.2024.1565

Mechanism and practice of structural modification to lateral overlying strata in gob-side entry for rockburst prevention

  • Pillarless (or small-pillar) mining method has been widely used. With increasing mining depth, the hard rock in the overlying strata leads to high stress concentration, extensive damage, and frequent high-energy dynamic events, which has become a major bottleneck in deep mining. In this study, the mechanism of rockburst prevention through the modification of lateral overlying strata was investigated. A mechanical model for lateral overlying strata was established, and an estimation method for the equivalent load of the upper overlying strata was proposed. The spatial structure characteristics and evolution of the lower overlying strata were revealed. A quantitative method for characterizing the stress in the coal seam induced by lower overlying strata movement was developed. A disaster-causing index was introduced, defined as the ratio of the combined static stress and disturbance stress from key layer fractures to coal seam strength, and a method for identifying key disaster-causing layers was proposed. The mechanical criterion for the instability of the key layer is defined, and the impact risk assessment is realized by comprehensively analyzing the membership degree of stress state and impact tendency index to “rockburst occurrence”. A method of lateral overlying strata modification and a rockburst prevention process were proposed and engineering practice was applied in the 6305 working face of the Xinjulong coal mine. The results showed that after active modification, the frequency of micro-seismic events increased by 33.3%, while the average energy of each event decreased by 23.5%. The stress concentration was significantly reduced, with the maximum reduction of about 27.2%. The deformation of the surrounding rock was significantly decreased, with a maximum reduction of about 104.7%. Moreover, the key disaster-causing layers has been eliminated, and the possibility of rockbursts was reduced from “high-likely” to “non-likely”.
  • loading

Catalog

    Turn off MathJax
    Article Contents

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return