煤矿地下水库煤岩变形特性的尺寸效应试验  

Experiment on size effect of coal and rock deformation characteristics in coalmine underground reservoir

作　　者：汪北方 武力 张晶 梁冰[4] 刘春保 WANG Beifang;WU Li;ZHANG Jing;LIANG Bing;LIU Chunbao(School of Mines,Liaoning Technical University,Fuxin,Liaoning 123000,China;State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,Beijing 100011,China;School of Science,Liaoning Technical University,Fuxin,Liaoning 123000,China;School of Mechanics and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000 [2]煤炭开采水资源保护与利用国家重点实验室,北京100011 [3]辽宁工程技术大学理学院,辽宁阜新123000 [4]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《采矿与安全工程学报》2021年第4期810-818,共9页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(51704139);煤炭开采水资源保护与利用国家重点实验室开放研究基金项目(SHJT-17-42.7);辽宁工程技术大学学科创新团队项目(LNTU20TD-05,LNTU20TD-17)。

摘　　要：煤矿地下水库煤岩变形不仅直接影响水库的储水能力,而且还严重威胁水库的稳定性。论文以神东矿区大柳塔煤矿地下水库为工程背景,选取拟建水库工作面采空区砂岩、泥岩和煤开展不同粒径煤岩碎胀与压实变形试验,揭示煤岩粒径对变形特性的影响规律。研究表明:自然或饱水条件下松散砂岩、泥岩和煤块试样的碎胀系数分别为1.587~1.828,1.591~1.787和1.435~1.753,且碎胀系数均随粒径增加呈对数曲线形式增大;混合粒径煤岩块试样碎胀系数介于各单一粒径之间,相同粒径煤块试样碎胀系数最小,泥岩块试样居中,砂岩块试样最大。加载煤岩块试样的应变和碎胀系数也均与粒径满足对数函数关系变化,相比自然煤岩块试样,饱水煤岩块试样碎胀系数变化幅度更为显著,饱水砂岩块碎胀系数变化为0.382~0.530,平均增幅9.45%,饱水泥岩块碎胀系数变化为0.410~0.627,平均增幅16.67%,饱水煤块碎胀系数变化为0.506~0.807,平均增幅13.34%。通过X射线衍射和扫描电子显微镜观测煤岩块试样矿物成分及细观结构,分析煤岩块内部组构特征与宏观力学性质关系,阐释应力-水岩作用下煤岩变形的尺寸效应,为煤矿地下水库储水量预测和稳定性控制提供理论依据。The deformation of coal and rock in coalmine underground reservoir not only directly affects the water storage capacity of the reservoir,but also seriously threatens the stability of the reservoir.With the underground reservoir of Daliuta coalmine in Shendong mining area as the engineering background,in this paper,sandstone,mudstone,and coal in the goaf of working face in the proposed reservoir were selected to carry out experiments on fracture expansion and compaction deformation of coal and rock with different block sizes,and the influence rule of coal and rock in different block sizes on deformation characteristics was revealed.The results have shown that the bulking coefficient is 1.587—1.828,1.591—1.787,and 1.435—1.753 for loose sandstone,mudstone,and coal block samples in their natural and saturated states respectively.The bulking coefficient increases in logarithmic curve with the increase of block size;the bulking coefficient of mixed block coal is between single blocks,and with the same lumpiness,the bulking coefficient of coal block is the smallest,mudstone middle,and sandstone the largest.The strain and the bulking coefficient of loaded coal block samples also meet the logarithmic function relation with the block size.Compared with natural coal block samples,the change range of the bulking coefficient of saturated coal-rock block is more significant.The bulking coefficient variation of saturated sandstone ranges from 0.382 to 0.530,with an average increase rate of 9.45%,that of saturated mudstone from 0.410 to 0.627,with an average increase rate of 16.67%,and that of saturated coal from 0.506 to 0.807,with an average increase of 13.34%.Then mineral composition and microstructure of coal rock sample were observed through diffraction of X-ray and scanning of electron microscope to analyze the internal fabric characteristics and macro mechanical properties of coal rock,and the size effect of coal rock deformation under the interaction of stress-water rock was explained,which provided theoretical bas

关 键 词：煤矿地下水库 饱水煤岩块 碎胀系数 单轴加载 压缩变形 尺寸效应 

分 类 号：TD821[矿业工程—煤矿开采]