煤矿安全2026，Vol.57Issue(2)：70-80,11.DOI:10.13347/j.cnki.mkaq.20250758
象山矿上保护层开采卸压保护范围研究
Research on pressure relief protection range of upper protective layer mining in Xiangshan Mine
摘要
Abstract
To address the technical challenges of sparse monitoring points in the protective range and significant errors in determin-ing protection boundaries during close-distance upper protective seam mining,this study takes the 21311 working face of Xiangshan Mine as the engineering background.By integrating FLAC3D numerical simulation with field multi-borehole joint measurements,a systematic analysis was conducted on the spatiotemporal evolution of the stress field,plastic zone,expansion deformation,and per-meability of the protected seam during upper protective seam mining.The effectiveness of gas control measures was also evaluated to achieve precise delineation of the pressure-relief range and optimization of the monitoring method.The results indicate that the floor stress field evolution exhibits a three-stage characteristic:"local pressure relief-symmetrical expansion-steady-state balance".The maximum vertical stress reduction in the pressure-relief zone reached 95%of the original rock stress.The plastic zone expanded in a"trapezoidal"pattern,with a maximum failure depth stabilized at 30 m,ensuring the protected seam entered a fully fractured and pressure-relieved state.The expansion deformation rate and permeability showed a"saddle-shaped"symmetrical distribution,with the permeability in the core pressure-relief zone increasing to 172.5 times its original value,providing favorable channels for ef-ficient gas drainage to optimize the field monitoring approach,20 boreholes were strategically arranged along the strike(Group A at the open-off cut side and Group D at the final line side)and dip(Group B at the auxiliary intake airway side and Group C at the main intake airway side)for intensive monitoring.Based on the critical expansion deformation rate index,the pressure-relief angles were accurately determined as 61° at the open-off cut side,58° at the final line side,79° at the auxiliary intake airway side,and 81° at the main intake airway side,significantly improving the accuracy of boundary identification.In combination with directional long bore-holes in the floor for intercepting and extracting downward pressure-relief gas,the maximum gas extraction rate reached 55.31%.The residual gas content in the protected seam was reduced to 2.29-3.90 m3/t,the permeability coefficient increased by 8-12 times,and the borehole gas flow decay coefficient decreased by approximately 40%-50%.关键词
上保护层开采/保护范围/膨胀变形率/测点优化/瓦斯治理Key words
mining of upper protective layer/protection range/expansion deformation rate/optimization of measurement point/gas control分类
矿业与冶金引用本文复制引用
钱万学,陈卫东,陈学习,陈星宇,薛浩源,张志远..象山矿上保护层开采卸压保护范围研究[J].煤矿安全,2026,57(2):70-80,11.基金项目
国家自然科学基金资助项目(52174181) （52174181）
河北省省级科技计划资助项目(22375401D) （22375401D）
中央高校基本科研业务费资助项目(3142023065) （3142023065）
