大采深综放开采覆岩移动规律离散元数值模拟研究  

Numerical study on the movement rule of overburden in fully mechanized caving mining with thick depth and high mining height

作　　者：余学义[1,2] 王昭舜 杨云 毛旭魏[1,2] YU Xueyi;WANG Zhaoshun;YANG Yun;MAO Xuwei(School of Energy,Xi'an University of Science and Technology,Xi'an 710054,China;Key Laboratory of Western Mines and Hazard Prevention of Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]西安科技大学能源学院,陕西西安710054 [2]西安科技大学,教育部西部矿井开采与灾害防治重点实验室,陕西西安710054

出　　处：《采矿与岩层控制工程学报》2021年第1期24-34,共11页Journal of Mining and Strata Control Engineering

基　　金：国家自然科学基金资助项目(51874230)。

摘　　要：为研究大采深综放开采条件下地表移动变形过程中上覆岩层的演化机理,在分析陈家沟煤矿八采区8512,8513综放工作面地表移动观测数据的基础上,确定了覆岩关键层特征参数及其控制作用,并应用3DEC离散元数值模拟软件,模拟同等开采条件下,多工作面开采后覆岩移动变形特征。通过方差与回归分析法分析模拟数据与实测数据的置信度为0.95,保证了模拟参数的科学性与合理性。模拟结果表明:工作面宽深比为0.24时,关键层2以下的岩层均断裂破坏,关键层2起着控制覆岩沉陷的作用,关键层2以上岩层在移动过程中还会出现离层结构,到达地表的沉陷量小于关键层2的挠曲量;工作面宽深比为0.48时,关键层2底部破断、结构失稳,会产生下沉突变;工作面宽深比为0.72时,关键层2完全破断,但由于关键层2上覆厚泥岩的作用,抑制导水裂缝带的发育,发育高度基本趋于稳定,高度为196 m,裂采比为16.3;工作面宽深比为0.96时,覆岩关键层2与其下伏岩层之间的离层闭合,关键层2的铰接结构范围在横向扩展的同时也伴随着整体下沉,关键层2下伏岩层破断后持续密实到一定程度之后,就不再继续下沉,只是随着开采范围扩大,下沉盆地横向发育,此时地表基本达到充分采动状态。此成果能够为该矿“三下开采”评价提供理论依据,为后期开采提供科学性指导,为大采深综放开采条件下地表移动变形规律提供理论参考。A numerical study was performed using the discrete element code 3DEC to study the evolution and ground movement of the overlying strata caused by the mining of a deep coal seam using full-mechanized caving method.The numerical model was constructed based on the geological and geotechnical conditions of the 8512,8513 working face in the No.8 mining area of Chenjiagou Coal Mine.The parameters of the key layer and its controlling effects were evaluated based on the monitoring data from the case.The confidence level of simulated data and measured data analyzed by variance and regression analysis method is 0.95,which ensures the scientificity and rationality of simulation parameters.The simulation results show that when the width-to-depth ratio of the longwall face is 0.24,the rock layers below the key layer 2 are all fractured and damaged,the key layer 2 plays a role in controlling the subsidence of the overlying rock,and the rock layers above the key layer 2 will also have a layered structure during the movement process,The amount of subsidence reaching the surface is less than the deflection of key layer 2;when the width-to-depth ratio of the longwall face is 0.48,the bottom of key layer 2 is broken and the structure is unstable,which will cause a sudden change in subsidence;when the width-to-depth ratio of the longwall face is 0.72,the key Layer 2 is completely broken,but due to the action of the thick mudstone overlying the key layer 2,the development of the water-conducting fracture zone is inhibited,and the development height is basically stable,the height is 196 m,the ratio of the fracturing height-to-mining height is 16.3;the width-to-depth ratio of the longwall face is 0.96.At the time,the separation layer between key layer 2 of the overburden and its underlying rock layer is closed.The hinged structure of key layer 2 expands laterally and is accompanied by overall sinking.The underlying rock layer of key layer 2 continues to be compacted to a certain extent after breaking After that,the sinking will not con

关 键 词：关键层 地表移动 覆岩移动 地表沉陷 科学采矿 

分 类 号：TD325[矿业工程—矿井建设]