基于PFC-GBM非均质模型的砂岩裂纹演化细观规律研究  

Microscopic law of sandstone crack evolution based on PFC-GBM heterogeneous model

作　　者：张国桥 孙鹏 吴祥业 王婧雅 郭文斌 田宇航 ZHANG Guoqiao;SUN Peng;WU Xiangye;WANG Jingya;GUO Wenbin;TIAN Yuhang(CHN Energy Group Wuhai Energy Co.,Ltd.,Wuhai 016040,China;School of Mining and Coal,Inner Mongolia University of Science and Technology,Baotou 014010,China;Inner Mongolia Key Laboratory of Mining Engineering,Baotou 014010,China;Inner Mongolia Research Center for Coal Safety Mining and Utilization Engineering and Technology,Baotou 014010,China;Inner Mongolia Cooperative Innovation Center for Coal Green Mining and Green Utilization,Baotou 014010,China;College of Mining,Chemistry and Chemical Engineering,Hulunbuir University,Hulunbuir 021008,China)

机构地区：[1]国家能源集团乌海能源有限公司,内蒙古乌海016040 [2]内蒙古科技大学矿业与煤炭学院,内蒙古包头014010 [3]内蒙古自治区矿业工程重点实验室,内蒙古包头014010 [4]内蒙古自治区煤炭安全开采与利用工程技术研究中心,内蒙古包头014010 [5]内蒙古煤炭绿色开采与绿色利用协同创新中心,内蒙古包头014010 [6]呼伦贝尔学院矿业与化学化工学院,内蒙古呼伦贝尔021008

出　　处：《中国矿业》2024年第9期158-169,共12页China Mining Magazine

基　　金：国家自然科学基金项目资助(编号:52264010);内蒙古自治区“高等学校青年科技人才发展项目”资助(编号:NJYT23065);内蒙古自治区直属高校基本科研业务费项目资助(编号:2023QNJS096)。

摘　　要：砂岩作为巷道围岩的重要组成部分,其细观损伤特征直接影响巷道围岩岩层稳定性。不同粒径的砂岩其矿物晶体的结构具有较明显的非均质性,为研究砂岩裂纹演化细观规律,综合运用室内试验、数值模拟及理论分析的方法,以现场巷道围岩钻取的三种不同粒径的砂岩试件为研究对象,基于PFC2D软件构建二维等效晶体模型Grain-Based Model(GBM),从细观角度分析非均质砂岩试件破裂过程裂纹演化规律。研究结果表明:砂岩试件颗粒粒径越小,岩石的总接触数量越多且晶间接触占总接触比例越小,单轴加载过程中岩石产生的声发射信号及裂纹内部产生的裂纹数量越多,岩石试件的单轴抗压强度越大且破坏模式越剧烈;三种不同粒径砂岩试件在裂纹演化规律上具有一致性,单轴加载过程中,砂岩内部裂纹演化顺序为晶间拉伸裂纹、晶内拉伸裂纹、晶间剪切裂纹、晶内剪切裂纹;砂岩各矿物晶体内部产生的裂纹数量与矿物含量成正比,与矿物晶体的强度成反比,矿物强度与单位面积裂纹数量系数Kl成反比;砂岩试样破坏时,拉伸裂纹占总裂纹数量的90%以上,拉伸破坏为砂岩在单轴压缩条件下的主要破坏类型。As an important part of roadway surrounding rock,the meso-damage characteristics of sandstone directly affect the stability of roadway surrounding rock.The mineral crystal structure of sandstone with different particle sizes has obvious heterogeneity.In order to study the mesoscopic law of sandstone crack evolution,the methods of laboratory test,numerical simulation and theoretical analysis are comprehensively used to study the three different particle sizes of sandstone specimens drilled from the roadway surrounding rock.A two-dimensional equivalent crystal Model Grain-Based Model(GBM)is constructed based on PFC2D software to analyze the crack evolution law of heterogeneous sandstone specimen during fracture process is analyzed from the microscopic point of view.The results show that the smaller the particle size of the sandstone specimen,the more the total contact number of the rock and the smaller the proportion of the intergranular contact in the total contact,the more acoustic emission signals generated by the rock and the more cracks generated inside the crack during uniaxial loading,the greater the uniaxial compressive strength of the rock specimen and the more severe the failure mode.The crack evolution laws of the three sandstone specimens with different particle sizes is consistent.In the uniaxial loading process,the internal crack evolution sequence of the sandstone is intergranular tensile crack,intracrystalline tensile crack,intergranular shear crack,and intracrystalline shear crack.The number of cracks generated in sandstone mineral crystals is proportional to the mineral content and inversely proportional to the strength of mineral crystals.The number of cracks per unit area coefficient Kl is defined,and the mineral strength is inversely proportional to Kl.Tensile cracks account for more than 90%of the total cracks when sandstone samples are damaged,and tensile failure is the main failure type of sandstone under uniaxial compression.

关 键 词：岩石力学 矿物晶体模型 破坏模式 尺寸效应 裂纹演化规律 

分 类 号：TD315[矿业工程—矿井建设]