尾砂胶结充填体裂纹演化多尺度特征  

Multi-scale characteristics of crack evolution of cemented tailings backfill

作　　者：赵康[1,2] 伍俊 严雅静 周昀 杨健 何志伟[1] ZHAO Kang;WU Jun;YAN Yajing;ZHOU Yun;YANG Jian;HE Zhiwei(School of Civil and Surveying and Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;Solids Waste and Chemicals Management Center,Ministry of Ecology and Environment,Beijing 100029,China)

机构地区：[1]江西理工大学土木与测绘工程学院,江西赣州341000 [2]生态环境部固体废物与化学品管理技术中心,北京100029

出　　处：《岩石力学与工程学报》2022年第8期1626-1636,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51764013);江西省主要学科学术和技术带头人培养计划领军人才项目(20204BCJ22005);江西省自然科学青年重点基金项目(20192ACBL21014)。

摘　　要：为了研究尾砂胶结充填体在单轴压缩作用下的裂纹演化特征,利用电子万能试验机、声发射、扫描电镜和DIC技术开展单轴受载胶结充填体损伤试验,探究胶结充填体从微裂纹的萌生、扩展、贯通,直至宏观裂纹产生的多尺度演化过程。研究表明:(1)试样单轴压缩过程中破坏模式属于延性破坏,裂纹贯通形式为剪切贯通。(2)胶结充填体内部微裂隙、孔洞呈弥散、随机分布,内部形态多以块状、团状、片网状存在,内部结构较致密,整体性较好。(3)加载初期试样裂纹扩展为张拉裂纹,后期裂纹扩展为剪切裂纹,二者共同作用产生了宏观主裂纹与次裂纹,裂纹间的贯通最终导致试样破坏。(4)同一时刻不同监测点的应变变化与其所处的试样空间位置有关,越靠近试样下端面,应变越大,应变变化幅度也越大;试样存在临界破坏区域,使得弹性与塑性应变、应变增幅之间存在明显的差异性。In order to study the crack evolution characteristics of cemented tailings backfill under uniaxial compression.The electronic universal testing machine,acoustic emission(AE),scanning electron microscope(SEM)and DIC technology were used to conduct damage tests on cemented backfill under uniaxial loading.The multi-scale evolution process of cemented backfill from micro-crack initiation,expansion and coalescence to macro-crack generation was investigated.The results show that:(1)The damage mode of the specimen during uniaxial compression is ductile damage,and the crack penetration is in the form of shear penetration.(2)The micro-cracks and pores in the cemented filling body are scattered and randomly distributed.The internal morphology is mostly in the form of blocks,clusters and sheet networks.The internal structure is compact and has good integrity.(3)Crack expansion of samples present as tension crack at the beginning of loading and later as shear crack.The two act together to produce macroscopic primary and secondary cracks.Eventually,the connection between cracks leads to the destruction of the specimen.(4)The strain variation at different monitoring points at the same moment is related to their position in the specimen space.The closer to the lower end of the specimen,the greater the strain and the greater the strain change.The existence of a critical damage region for the specimen makes the difference between elastic and plastic strains and strain increase obvious.

关 键 词：采矿工程 多尺度 尾砂胶结充填体 裂纹演化 声发射 DIC监测 应变增幅 

分 类 号：TD32[矿业工程—矿井建设]