单轴压缩下充填体声发射特性及损伤演化研究  

Study on backfill acoustic emission characteristic and damage evolution under uniaxial compression

作　　者：谢勇[1,2] 何文[3,2] 朱志成[3,2] 刘贤俊[1,2] 刘浩[3,2] 谢涛[1,2] 

机构地区：[1]江西理工大学建筑与测绘工程学院,赣州341000 [2]江西理工大学江西省矿业工程重点实验室,赣州341000 [3]江西理工大学资源与环境工程学院,赣州341000

出　　处：《应用力学学报》2015年第4期670-676,710,共7页Chinese Journal of Applied Mechanics

基　　金：江西省科技支撑计划项目(20141BBG70097);江西省自然科学基金(20132BAB216019);江西省工业安全工程技术研究中心开放基金(2013GGY001);江西理工大学科研基金重点项目(NSFJ2014-K05)

摘　　要：通过水泥胶结分级尾砂充填体单轴抗压声发射试验,研究分析了整个充填体压缩破坏过程中的声发射能率、声发射b值、声发射能率分形维数与时间的关系曲线。试验结果表明:加载初期的声发射活动并不明显,直到加载至应力峰值时,声发射活动显著增强。同时分析表明:声发射b值和声发射能率分形维数曲线呈现明显的波动性,破坏前其曲线均表现出上升趋势,临近破坏时声发射b值和声发射能率分形维数都下降到最低值。利用声发射b值和声发射能率分形维数能较好地描述充填体在单轴抗压破坏时裂隙的产生、扩展至完全破坏情况,将声发射b值和声发射能率分形维数两者结合作为现场监测充填体稳定性的指标,可为矿山现场安全监测提供比单一声发射参数更为有效的依据。最后根据声发射累计能率定义损伤变量,建立了充填体压缩破坏过程中的损伤演化方程,进而得到了单轴压缩条件下充填体的损伤本构模型。Acoustic emission experiments are conducted to monitor cemented classified tailing backfill under uniaxial compression. Relationship curves of AE energy rate, b value, fractal dimension and time during the process of backfill compressive destruction are analyzed. Experimental results show that AE activities are not clearly observed at the preliminary stage of loading, and not until it reaches the peak stress of loading do AE activities significantly enhance. Meanwhile, b value and fractal dimension of AE energy rate present a great fluctuation during the tests. Before the failure of backfill, both b value and fractal dimension curves show trend of increasing and b value and fractal dimension decrease to minimum values when it approaches to the failure of backfill. Conclusions can be drawn that both b value and fractal dimension of AE energy rate can provide good descriptions of the whole process from crack generation and growth in the backfill to its failure. The combination of b value and fractal dimension of AE energy rate can provide more accurate criteria for in situ backfill safety monitoring in the mining industry than a single AE parameter does. Finally, damage variable is defined based on cumulative AE energy rate and damage evolution equation of backfill during compressive failure process is established and the damage constitutive equation of backfill is revealed.

关 键 词：充填体 声发射b值 分形维数 安全监测 损伤变量 

分 类 号：TD323[矿业工程—矿井建设]