巨厚松散层下软弱覆岩破坏规律  

Failure law of weak overburden stratum underlying extra-thick alluvium

作　　者：张广超 陶广哲 孟祥军[1,2] 李友 曲治[1] 绪瑞华 于善昌 陈淼 周广磊[1] 栾恒杰 ZHANG Guangchao;TAO Guangzhe;MENG Xiangjun;LI You;QU Zhi;XU Ruihua;YU Shanchang;CHEN Miao;ZHOU Guanglei;LUAN Hengjie(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Shandong Energy Group Co.,Ltd.,Jinan 250014,China;Guotun Coal Mine,Linyi Mining Group Heze Coal and Power Co.,Ltd.,Heze 274000,China)

机构地区：[1]山东科技大学能源与矿业工程学院,山东青岛266590 [2]山东能源集团有限公司,山东济南250014 [3]临沂矿业集团菏泽煤电有限公司郭屯煤矿,山东菏泽274000

出　　处：《煤炭学报》2022年第11期3998-4010,共13页Journal of China Coal Society

基　　金：国家自然科学基金青年基金资助项目(51904164);山东省自然科学基金资助项目(ZR2018QEE001)。

摘　　要：为研究巨厚松散层下软弱覆岩破坏规律,以巨野矿区郭屯煤矿3301工作面为工程背景,综合运用理论分析、数值模拟与现场实测相结合的研究方法对巨厚松散层下软弱覆岩破坏规律进行了研究。得出:①阐明了巨厚松散层软弱岩层条件下覆岩破坏演化力学过程,明确了巨厚松散层、软弱基岩及两者联动演化对覆岩破坏高度的综合影响机制,并考虑到软弱岩层塑性破裂特征,提出了基于极限拉伸应变的软弱覆岩破坏高度计算方法;②揭示了巨厚松散层下软弱覆岩破坏形态及裂隙发育拓展规律,软弱覆岩破坏演化依次经历缓慢增长阶段、快速增长阶段与稳定平衡阶段,分析了松散层厚度、开采高度对软弱覆岩破坏的影响机制,覆岩破坏高度与采高呈线性增长关系,与松散层厚度呈指数函数关系,并基于回归分析理论拟合得出了相应的数学表达式;③井下仰孔分段注水现场探测表明,巨厚松散层(515 m)、软弱岩层、大采高(6 m)开采条件下的覆岩破坏高度为78 m,为采高的13倍,发育至弥合性较强的泥岩岩层内,并基于工作面水害危险性分析、涌水规律及采场矿压规律,对理论分析和数值模拟结果进行了验证分析。The failure law of weak overburden stratum is an important factor affecting the safe mining of coal.A comprehensive method including field investigation,theoretical analysis,numerical simulation was applied to investigate the failure law of weak overburden stratum underlying extra-thick alluvium based on the geological conditions of the 3301 working face of the Guotun coal mine in the Juye mine area.The results were obtained as follows:①This paper reveals the mechanical evolution process of weak overburden stratum underlying extra-thick alluvium,illustrates the comprehensive influence mechanism of alluvium thickness,bedrock and their linkage evolution,and proposes the method to predict the height of weak overburden stratum failure based on the plastic fracture characteristics.②The failure form and fracture development and expansion law of failure law of weak overburden stratum underlying extra-thick alluvium are clarified,and the development of failure law of weak overburden stratum successively experiences three stages:slow growth stage,rapid growth stage,and stability stage.The influence mechanism of loose layer thickness and mining height on the failure of weak overburden is analyzed.The height of weak overburden stratum has a linear relationship with the mining height,an exponential function relationship with the thickness of alluvium,and the corresponding mathematical expressions are fitted based on a regression analysis method.③The results of the downhole segmented water injection method show that the failure height under the conditions of extra-thick alluvium(515 m),weak overburden stratum and large mining height(6 m)is 78 m,which is 13 times of the mining height,and developed into the mudstone rock strata.The theoretical analysis and numerical simulation results are verified based on the water hazard analysis,water inflow and stope ground pressure law of the working face.

关 键 词：软弱岩层 巨厚松散层 覆岩破坏高度 塑性破裂 大采高开采 

分 类 号：TD325[矿业工程—矿井建设]