深埋薄基岩采场覆岩冒落拱与拱脚高耸岩梁复合承载结构形成机理与应用  

Development and application of overburden structure composed of caving arch and towering roof beam in deep longwall panel with thin bedrock

作　　者：王兆会[1,2] 唐岳松 李猛 吴山西[1,2] 孙文超 李家龙 水艳婷 WANG Zhaohui;TANG Yuesong;LI Meng;WU Shanxi;SUN Wenchao;LI Jialong;SHUI Yanting(School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Top-coal Caving Mining Research Center of Coal Mining Industry,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]放顶煤开采煤炭行业工程研究中心,北京100083

出　　处：《煤炭学报》2023年第2期563-575,共13页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51934008,51904304);中央高校基本科研业务费资助项目(2022YQNY13)。

摘　　要：焦作煤田赋存深埋厚冲积层薄基岩煤层,覆岩构成的特殊性导致顶板活动剧烈、地表下沉系数大,采场面临强矿压、突水溃沙威胁,沉陷区出现裂缝和积水,破坏房屋和农田。为提高深埋薄基岩采场围岩控制效果,以赵固二矿14030工作面为工程背景,采用室内试验、理论分析和现场实测等手段研究覆岩采动裂隙发育特征、顶板结构形态与承载机理,探究支架选型与灾害防控方法。结果表明:覆岩变形存在初始静止、慢速增长、快速增长和突变增长4个阶段,前2个阶段覆岩稳定,第3阶段因变形局部集中进入非稳定状态,第4阶段因非连续变形进入裂隙发育进程;采动裂隙萌生于高位厚冲积层,下行扩展导致基岩全厚断裂,形成覆岩冒落拱与拱脚高耸岩梁复合结构;覆岩连续变形受关键层控制,非连续变形由冲积层冒落裂隙主导;基于关键层沉降特征解释了采动裂隙萌生于高位厚冲积层的原因,揭示了裂隙下行扩展并贯穿岩层交界面的能量原理,采用断裂力学理论推导了基岩发生全厚剪切破断的力学条件;构建了冲积层冒落拱与拱脚高耸岩梁复合结构力学模型,提出了冒落拱极限承载能力与实际边界载荷计算方法,得到了冒落拱发生结构失稳的力学判据,采动应力旋转促进冲积层载荷向拱脚两侧传递,增强了冒落拱自稳能力;提出了基岩破断面恒定法向刚度条件下高耸岩梁承载能力计算方法,确定了保持岩梁平衡所需支架具备的支撑能力;基于厚冲积层冒落拱与拱脚高耸岩梁复合承载机理,提出了液压支架强度-刚度双参量选型方法和覆岩突水溃沙通道快速识别方法,实测结果表明赵固二矿14030工作面支架选型基本合理,突水溃沙通道识别则为顶板注浆钻孔参数确定提供了指导。Deep coal seam with an overburden of thin bedrock and thick alluvium is affluent in Jiaozuo coalfield.Due to the special composition of overburden,roof movement is active and surface subsidence coefficient is large.Mining activity is threatened by strong mining pressure and water-sand inrush accident.The fracture and water are observed at the surface of mined-out area,which destroys buildings and agricultural land.In order to improve ground control in such longwall panels,overburden fracture development,structure formation and its bearing mechanism are analyzed by taking No.14030 longwall panel in the second coal mine of the Zhaogu mining area as the background.Based on the results from laboratory test,theoretical analysis and field measurement,the overburden deformation is divided into four stages,including initial static,slow increase,quick increase and catastrophe increase stages.The overburden is stable in the first two stages.It becomes instable due to deformation localization in the third stage and a fracture development appears due to discontinuous deformation in the last stage.Mining induced fracture initiates in the thick alluvium,propagating downward into the bedrock.Full-thick rupture of the bedrock leads to the formation of overburden structure composed of caving arch and towering roof beam.Overburden movement is dominated by the key stratum in the continuous stage,which becomes dominated by the fracture propagation of the alluvium in the discontinuous stage.Fracture initiation is explained based on the deformation characteristics of the key stratum.The energy principle is used for explaining the fracture penetration phenomenon at the bedding plane.Full-thick shear rupture condition for the bedrock is deduced from fracture mechanics.After that,the mechanical model is established for the overburden structure composed of caving arch and towering roof beam.Load-bearing capacity and actual load transmitted onto the caving arch are determined,which reveals the structural instability condition of the arch.M

关 键 词：薄基岩 厚冲积层 覆岩裂隙 冒落拱 高耸岩梁 承载机理 

分 类 号：TD325[矿业工程—矿井建设]