摘要
针对浅埋采空区下特厚煤层开采时存在的覆岩运移及地表沉降等问题,以新疆伊北矿区潘津工业煤矿23-25#煤回采为背景,采用理论分析结合数值模拟的方法深入分析了采空区下倾斜特厚煤层回采时的采动裂隙发育形态、地表下沉变形等采动特征,并结合钻孔取芯探测及地表移动观测结果,准确测定该矿采空区下特厚煤层回采时的覆岩两带高度。研究发现:浅埋采空区下特厚煤层回采时,层间关键层受下部煤层回采扰动影响发生梁式失稳,层间岩体破碎形成散体结构矸石,同时引起上方矸石的二次垮落及亚关键层块体铰接结构的二次破坏,覆岩裂隙向上发育但主控关键层基本稳定承压。大空间采场低位关键层难以形成比较稳定的块体铰接结构,破断后在采空区边缘形成明显的断裂空洞与裂隙,同时覆岩运移及地表沉陷受煤层倾角影响呈现明显的偏斜。23-25#煤回采后的垮落带高度为75 m左右,裂隙带高度为185 m左右。
This study is focused on the issue of overburden movement and surface subsidence during ex-tra-thick coal seam mining under a shallow goaf.With the 23-25#coal seam mining in Panjin Industrial Coal Mine in the Yibei mining area of Xinjiang as the research background,the characteristics of mining-induced fracture development and surface deformation during extra-thick coal seam mining under a goaf were thoroughly analyzed through theoretical analysis and numerical simulation.Furthermore,the heights of"two zones"(collapsed zone and fracture zone)in the overburden during extra-thick coal seam mining under a goaf were accurately determined by integrating the results of core drilling and sur-face movement monitoring.The research findings reveal that,during extra-thick coal seam mining under a shallow goaf,the interlayer key stratum undergoes beam instability as a result of disturbances from the mining of the lower coal seam.This not only leads to the fragmentation of interlayer rock mass and the formation of a loose rubble structure,but also induces secondary collapse of overlying gangue and secondary damage to the block joint structure of the sub-key stratum.While fractures in the overburden develop upward,the main controlling key stratum bears the pressure stably.In large mining spaces,it is difficult for the low-position key strata to form a relatively stable block joint structure.After breaking,distinct fracture voids and cracks emerge at the edges of the goaf.Additionally,the overburden movement and surface subsidence are obviously skewed due to the influence of the coal seam dip angle.The heights of the collapsed zone and the fracture zone after the 23-25 coal seam mining are approximately 75 m and 185 m,respectively.
作者
李小鹏
刘少伟
付孟雄
何亚飞
张建英
郭重托
LI Xiaopeng;LIU Shaowei;FU Mengxiong;HE Yafei;ZHANG Jianying;GUO Chongtuo(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454003,China;State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization,Jiaozuo,Henan 454003,China;Yili Yongning Coal Chemical Co Ltd,Yining,Xinjiang 844500,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期845-855,共11页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52074102)
中原科技创新领军人才项目(244200510013)
河南省高校科技创新团队项目(23IRTSTHN007)
河南省科技攻关项目(242102321105)。
关键词
特厚煤层
采空区下
重复扰动
覆岩裂隙
两带发育
extra-thick coal seam
under the goaf area
repetitive disturbance
overburden rock frac-tures
development of“two zones”
