综放工作面过密集空巷群高水充填技术研究及应用

High water filling technology for fully mechanized top-coal caving face crossing close-set abandoned roadway groups

针对整合矿井残煤复采综放工作面过密集空巷群问题,采用理论分析和数值模拟方法研究了综放工作面超前支承压力对空巷群稳定性的影响,确定了全空间高水充填材料的合理强度。研究结果表明:综放工作面超前支承压力与空巷群侧向支承压力相互叠加,会造成工作面与空巷群之间的煤柱及空巷群自身的煤柱进入塑性屈服状态,易诱发密集空巷群及其顶板大范围采场围岩失稳;随综放工作面与空巷间煤柱宽度的减小,空巷充填体所需的支撑强度近线性增加,随充填体强度的提高,全空间充填体抑制空巷顶板下沉变形的能力近线性增大;综合理论计算和数值模拟结果,确定了荆宝煤业3号煤层全空间充填空巷群的高水充填体强度不小于2.5MPa,现场实践验证了充填材料设计强度的合理性和全空间高水充填技术的有效性,保证了工作面安全高效通过空巷群,避免了充填体材料过低带来的潜在安全隐患,也解决了充填体强度过高造成的经济投入浪费,为类似条件下工作面过密集空巷群高水充填技术的推广应用奠定了理论基础和实践经验。

Aiming at the problems in top-coal caving face crossing close-set abandonded roadway groups in residual coal mining of integrated coal mines, the influence of abutment pressure induced by fully mechanized top coal caving face on the stability of close-set abandoned roadway groups was studied with theoretical analysis and numerical simulation. The suitable strength of backfill material was also determined. The results show that the superposition of the advance abutment pressure induced by mining and roadway excavation separately will lead the pillars into plastic yield state, which is likely to trigger the instability of the abandonded roadway groups and the roof above the pillars. With the decrease of coal pillar width between mining face and abandoned roadway, the required support strength of filling material should be increased. As the strength increase of filling material, its ability to support the roof enhances almost linearly. Based on the theoretical anaylsis and numerical simulation results, it is determined that the strength of high water filling material for No.3 coal seam in Jingbao coal industry is not less than 2.5 MPa. The field application indicates that the design strength of filling materials is rational and the whole space high water filling technology can ensure the mining face safely crossing the abandoned roadway groups, and the safety hazards during mining is avoided with the proposed technology. It can also save investment without over-strong filling material, and provide theoretical foundation and practical experience for the promotion and application of the high water filling technology in close-set abandoned roadway groups.