摘要
为研究结构面对节理煤体单轴压缩力学行为的影响,首先基于结构面实测与参数标定试验构建合成煤体模型,然后分别针对REV尺寸煤块与煤体进行不同加载方位的单轴压缩数值试验,分析结构面对节理煤体力学行为的影响机制以及裂隙的形成机制。结果表明:(1)所构建的合成煤体模型可表征研究煤体,其REV为1. 0 m×1. 0 m×2. 0 m;(2)结构面弱化煤体单轴抗压强度与弹性模量,增大煤体单轴压缩变形,弱化/增强程度取决于加载方位与结构面的方位关系;(3)结构面决定煤体单轴压缩破坏方式,煤体表现为平行加载方向的劈裂破坏,加载方位不同劈裂形态不同;(4)提出了可量化评价基质破坏与结构面活化对节理岩体破坏贡献程度的指标:基质破坏贡献比和结构面活化贡献比;(5)平行加载方向的结构面在加载力作用下激活为活化原生裂隙,并在其端部发育出翼裂纹,形成压致拉裂裂隙组合。对于包含非贯穿结构面的煤体,裂隙组合彼此连通形成劈裂裂隙;对于包含贯穿结构面的煤体,贯穿的活化原生裂隙直接形成劈裂裂隙。
To investigate the influence of joints on uniaxial compression behavior of jointed coal,the synthetic coal mass specimen was first constructed based on the in-situ measurement of joints and numerical parameters calibration tests.Then the numerical uniaxial compression tests on intact coal and jointed coal with REV size under different loading orientations were conducted.Finally,the influence mechanism of joints on the mechanical behavior of jointed coal and the fracture formation mechanism were analyzed.The study shows that:①The constructed synthetic coal mass model can represent the jointed coal investigated,with the REV equaling to 1.0 m×1.0 m×2.0 m.②Joints weaken the UCS and elastic modulus,but increase the deformation of jointed coal under uniaxial compression,with the weakening/increasing degree depending on the relation between loading orientations and joints.③Joints determine the failure mode of jointed coal under uniaxial compression.The jointed coal by splitting fracture parallel to loading directions,with different splitting geometries under different loading orientations.④The contribution ratio of matrix failure and the contribution ratio of joints activation were put forward,which can be used to quantitatively evaluate the contribution degree of matrix failure and joints activation to the failure of jointed rock,respectively.⑤The joint parallel to loading orientation is converted to activated pre-existing fracture under the effect of loading force,from the end of which grow the wing crack,both of which form the compression-induced tension fracture composition.For jointed coal containing non-penetrating joints,the splitting fractures are formed by the coalescence of fracture compositions.For the coal mass containing through joints,the splitting fractures are formed only by the through activated pre-existing fractures.
作者
王晓卿
康红普
高富强
赵科
WANG Xiaoqing;KANG Hongpu;GAO Fuqiang;ZHAO Ke(Coal Mining and Designing Department,Tiandi Science & Technology Co.,Ltd.,Beijing 100013,China;Coal Mining Branch,China Coal Research Institute,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2018年第11期3088-3097,共10页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51774185)
中国煤炭科工集团科技创新创业资金专项资助项目(2018QN017)
天地科技股份有限公司开采设计事业部科技创新基金资助项目(KJ-2015-TDKC-06)
关键词
节理煤体
单轴压缩
结构面
基质裂隙
离散元模拟
jointed coal
uniaxial compression
joints
matrix fracture
DEM simulation
作者简介
王晓卿(1988—),男,河北高邑人,助理研究员,博士。E-mail:wangxiaoqing@tdkcsj.com;通讯作者:康红普(1965-),男,山西五台人,中国工程院院士,研究员,博士生导师。E-mail:kanghp@163.com.
