硬岩顶板切顶留巷围岩变形分区补强控制研究

Partitioned reinforcement control study of surrounding rock deformation in hard-rock roof cutting roof and staying roadway

【目的】森达源煤矿传统的宽煤柱开采方式导致采掘接续紧张,并引发严重的围岩变形问题。切顶留巷技术可优化巷道支护条件,提高采煤效率,促进煤矿高效安全生产。【方法】以1号煤层的10101工作面为研究对象,运用FLAC 3D数值模拟软件,深入探究了切顶高度、切顶角度、注浆加固深度对巷道掘进、预裂切顶和切顶留巷过程中煤帮内部、采空区及顶板应力变形特性的影响。确定出最佳切顶留巷方案。在此基础上,进一步模拟分析工作面前后不同区域的围岩受力变形情况。提出回采工作面前方0~30 m内为超前补强区,采取“高预应力锚索+单体配合铰接顶梁”的联合支护。后方0~100 m内为滞后补强区,采用“工字钢+单体支柱”联合支护,同时对矸石帮实施注浆加固。通过工程应用验证了区分补强控制变形措施的有效性。【结果】结果显示:最佳切顶留巷方案为切顶高度6 m,切顶角度15°,矸石帮注浆深度1 m。此方案下,10101工作面的巷道顶底板的最终变形量为155 mm,两帮的为84 mm,均符合矿井使用要求,验证了切顶留巷技术具有良好效果。【结论】结果表明:切顶留巷技术能有效解决传统宽煤柱开采方式中存在的围岩变形问题。然而,该技术的实施受切顶高度、切顶角度和矸石帮注浆深度等因素的影响较大,需结合数值模拟和现场状况进行具体确定。总体上,切顶留巷技术和分区补强控制措施对围岩变形的控制效果显著,为类似条件下的煤矿开采提供了宝贵的经验借鉴,因而具有广阔的应用前景。

[Objective]The traditional wide coal pillar mining method in SENDAYUAN coal mine leads to tense mining succession and serious surrounding rock deformation problems.Cutting roof and leaving roadway technology can optimize roadway support conditions,improve coal mining efficiency,and promote efficient and safe production in coal mines.[Methods]Taking 10101 working face of No.1 coal seam as the research object,FLAC 3D numerical simulation software was used to systematically analyses the effects of cutting roof height,cutting roof angle,and grouting reinforcement depth on the stress and deformation inside internal coal gang,goaf,and the roof during roadway drivage,pre-cracking cutting and cutting and leaving the roadway.And determine the best cutting roof and staying roadway schemes.On this basis,further simulation analyses the surrounding rock deformation in different areas in the front and back of workings.It is proposed that,0~30 m in front of workings as over-advanced reinforcement area,adopting the joint support of“high pre-stressing anchor cable+monobloc with articulated roof beam”.0~100 m behind the working as the lagging reinforcement area,adopting the joint support of“I-beam+monolithic pillar”,and at the same time,the gangue gang is reinforced by grouting.And the effectiveness of the zonal reinforcement measures was verified through engineering applications.[Results]The result show that the best roof cutting and retaining roadway program for the cutting roof height 6 m,cutting roof angle 15°,grouting reinforcement depth 1 m.The actual project of 10101 working face,the final amount of the top and bottom of the roadway plate is 155 mm,two gangs is 84 mm,are in line with the requirements of the use of mines,verifying that the cutting roof and staying roadway technology has a good effect.[Conclusion]The result show that the cutting roof and staying roadway technology can effectively solve the perimeter rock deformation problems existing in the traditional wide pillar mining method.However,the implementation of this technology is greatly affected by cutting roof height,cutting roof angle and gangue gang grouting reinforcement depth,which need to be combined with numerical simulation and site conditions for specific determination.Overall,cutting roof and staying roadway technology and partitioned reinforcement control measures have significant effect on the control of surrounding rock deformation,which provides valuable experience for coal mining under similar conditions,and thus has a broad application prospect.