摘要
基于龙华煤矿20202工作面地质条件,通过无人机定点航拍明确了研究区地形典型特征,以多点、多组、多区域煤岩体力学参数表面-跨孔原位测试结果作为细观界面参数,建立了平缓、沟谷地形下的PFC2D数值模型,基于覆岩结构分析、位移场演化、关键层应力演化和力链分布特征揭示了近浅埋厚煤层开采覆岩结构失稳破断规律。研究结果表明:复合基本顶以“非对称三铰拱”和“斜台阶岩梁”的结构发生破断,破断步距、覆岩载荷传递幅度和来压强度受多关键层破断模式的影响,多关键层“同步破断”模式矿压显现剧烈程度显著大于“近同步破断”模式;沟谷地形黄土覆盖层的厚度和坡角直接影响覆岩的破断步距,工作面过沟谷沟底时覆岩破断形成贯通断裂线的夹角与黄土覆盖层的厚度和坡角正相关。所得覆岩结构失稳破断结果与现场实测支架工作阻力特征基本一致,证明基于原位测试方法综合确定的细观界面参数所建立的颗粒流数值模型准确性和可靠度较高。
Based on the geological conditions of the 20202 working face in Longhua Coal Mine,this study identified typical topographic features of the study area through fixed-point aerial photography by UAV,and the PFC*D numerical model under gentle and gully terrains was established by taking surface and cross-hole in-situ test results of mechanical parameters of coal and rock masses from multiple points,groups,and zones as mesoscopic interface parameters.Moreover,the instability and fracturing mecha-nisms of overburden strata in shallow-buried thick coal seam mining were revealed based on the analysis on overburden structure,displacement field evolution,key stratum stress evolution,and force chain dis-tribution characteristics.The following findings were yielded:The compound main roof fractures in structures resembling an"asymmetric three-hinged arch"and a"slanting step voussoir beam",and the fracturing intervals,load transfer magnitude,and weighting intensity are affected by the fracturing modes of multiple key strata.The mining pressure manifestation in the"synchronous fracturing"mode of multiple key strata is much more intense than that in the"near-synchronous fracturing"mode.The thickness and slope angle of the loess-covered layer in the valley terrain directly affect the fracturing interval of the overlying strata.When the working face passes through the gully bottom,the included angle of the penetrating fracturing line formed by overburden fracturing is positively correlated with the thickness and slope angle of the loess-covered layer.The obtained results of overburden structure instability and fracturing are basically consistent with the field-measured shield working resistance characteristics,which proves that the particle flow numerical model established based on mesoscopic interface parameters comprehensively determined through in-situ tests is pretty accurate and reliable.
作者
武兆鹏
梁运培
万志军
赵米真
王力
李其罡
刘思辰
申飞
WU Zhaopeng;LIANG Yunpei;WAN Zhijun;ZHAO Mizhen;WANG Li;LI Qigang;LIU Sichen;SHEN Fei(State Key Laboratory of Coal Mine Disaster Dynamics and Control,School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China;Key Laboratory of Deep Coal Resource Mining(CUMT),Ministry of Education of China,School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Sunjiacha Longhua Mining Co Ltd,Shaanxi Coal Chemical Industry Group,Yulin,Shaanxi 719314,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期868-878,共11页
Journal of Mining & Safety Engineering
基金
国家重点研发计划项目(2022YFC3004704)
国家自然科学基金项目(52174166)。
关键词
近浅埋煤层
沟谷地形
颗粒流
覆岩结构
near-shallow buried coal seam
gully terrain
particle flow code
overlying strata structure
