摘要
层理是煤层的主要构造标志,通过CT扫描与扫描电镜开展层理的观察,采用室内试验及PFC2D程序,构建含不同层理倾角的煤岩试样,对其进行单轴压缩试验,研究其在不同层理倾角条件下的强度、破坏模式及裂纹分布情况。研究结果表明:1)在单轴压缩条件下,试样的抗压强度试验值与计算值均随着层理倾角的增大呈现出先减小后增大的规律,近似为“V”字形,当层理倾角为0°时均取得最大值,当层理倾角为60°时均取得最小值。2)当层理倾角为0°时,试样破坏模式为脆性破坏,高速弹射出大量碎屑,表现出很强的冲击能力;当倾角为30°,45°与60°时,试样破坏模式为剪切破坏,破裂面与层理面平行;当倾角为90°时,试样破坏模式为劈裂破坏,破裂面与轴向力方向呈小角度。3)当层理倾角为0°与90°时,试样裂纹主要集中于加载端部与试样中部,且其发展方向与加载方向呈一定夹角,其中以张拉型裂纹为主,含少量剪切型裂纹;当倾角为30°,45°与60°时,裂纹主要沿层理面发展,以张拉型裂纹为主,含少量剪切型裂纹。
The bedding is the main structural symbol of coal seams.The bedding was observed through CT scanning and scanning electron microscopy,and indoor tests and PFC2D programs were used to construct coal and rock samples with different bedding inclination angles.Uniaxial compression tests were carried out to study the strength,failure mode and crack distribution of samples with different bedding dip angles.The results show that:1)Under uniaxial compression,the experimental and calculated compressive strength of the samples decrease first and then increase with the increase of the bedding inclination angle,which is approximately in the shape of a"V"shape,and reach the maximum and minimum values when the bedding inclination angleαis 0°and 60°,respectively.2)When the bedding inclination angle is 0°,the failure mode of the sample is brittle failure,and a large amount of debris is ejected at high speed,showing strong impact ability.When the inclination angle is 30°,45°and 60°,the failure mode of the sample is shear failure,and the fracture surface is parallel to the bedding surface.When the inclination angle is 90°,the failure mode of the sample is split failure,and the fracture surface is at a small angle in the axial force direction.3)When the bedding inclination angle is 0°and 90°,the sample cracks are mainly concentrated on the loading end and the middle of the sample,and the development direction and the loading direction are at a certain angle,in which tension-type cracks are dominant,with a small amount of shear type cracks.When the inclination angles are 30°,45°,and 60°,the cracks mainly develop along the bedding plane,in which the tension-type cracks is dominant and contains a few shear cracks.
作者
周喻
李程
王文林
周贤
ZHOU Yu;LI Cheng;WANG Wenlin;ZHOU Xian(Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine,University of Science and Technology Beijing,Beijing 100083,China;Shaanxi Huabin Coal Industry Co.Ltd.,Xianyang 713500,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第10期4036-4047,共12页
Journal of Central South University:Science and Technology
基金
中央高校基本科研业务费专项资金资助项目(FRF-IDRY-20-024)
国家自然科学基金资助项目(51504016)。
关键词
层理煤岩
单轴压缩
CT扫描
扫描电镜
颗粒流程序
bedding coal
uniaxial compression
CT scan
scanning electron microscope
particle flow code(PFC)
