摘要
纤维增强充填体(FRB)在采空区充填中具有明显的优势,为研究FRB微观破坏机制,以不同配比的玻璃纤维增强超细尾砂充填体为研究对象,利用电子万能试验机、扫描电镜、核磁共振仪和声发射监测仪开展系列试验,从微观层面系统分析FRB的裂隙扩展及损伤演化过程。研究表明:玻璃纤维的掺入能够显著优化充填体材料的初始结构,减少初始缺陷,其中以灰砂配比为1∶12试件的优化效果最为明显;FRB试件和无纤维充填体(CPB)试件的破坏模式存在显著的区别:CPB试件破坏以主裂隙贯穿试件为主,局部位置存在剥落现象,而FRB试件破坏则以较多的小尺度次生裂隙为主,这是由于纤维对充填体材料的阻裂作用所致。因纤维的阻裂作用也使得FRB和CPB的声发射(AE)特性呈现明显的差异:CPB试件在屈服点σ_(cd)(约在85%应力峰值)之后,振铃计数出现“AE下降区”,而FRB试件在屈服点σ_(cd)之后,振铃计数则表现出明显的“AE上升区”。研究结果不仅能够为推广玻璃纤维充填体的应用提供理论指导,且可为玻璃纤维增强充填体达到其峰值强度预测提供声发射判据。
Fiber-Reinforced Backfill(FRB)has obvious advantages in filling the of goafs.To investigate the microscopic damage mechanism of FRB,a series of tests were conducted on glass fiber reinforced ultra-fine tailings backfill with different cement tailings ratios by using compression machine,scanning electron microscope,nuclear magnetic resonance instrument and acoustic emission monitor to systematically analyze the fracture expansion and damage evolution process of FRB from microscopic level.Studies have shown that:the incorporation of glass fiber can improve the initial structure of the backfill material and reduce the initial defects,among which the improvement effect is most obvious for the specimen with 1∶12 cement tailings ratio.There are obvious differences between the damage patterns of CPB and FRB.The damage of CPB is dominated by primary fissures through the specimen,with spalling at local locations,while the damage of FRB is dominated by more small-scale secondary fissures,which is caused by the crack-resisting effect of glass fibers on the backfill material.Due to this reason,the acoustic emission(AE)characteristics of FRB and CPB also show a significant difference:the CPB specimen shows an“AE drop zone”in the ringing count after the yield point(about 85%of the peak stress),while the FRB specimen shows an“AE rise zone”in the ringing count after the yield point.The results of the study can not only provide theoretical guidance for promoting the application of glass fiber reinforced backfills,but also provide acoustic emission criteria for predicting the peak strength of FRB materials.
作者
赵康
何志伟
严雅静
于祥
宋宇峰
杨健
ZHAO Kang;HE Zhiwei;YAN Yajing;YU Xiang;SONG Yufeng;YANG Jian(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;Lingbao Jinyuan Mining Company Limited,Lingbao,Henan 472500,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第S01期3010-3020,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)
关键词
采矿工程
纤维增强充填体
超细尾砂
玻璃纤维
核磁共振
裂隙演化
声发射特征
mining engineering
fiber reinforced backfill
ultra-fine tailings
glass fibers
nuclear magnetic resonance
fracture evolution
acoustic emission signature
作者简介
赵康(1980–),男,2012年于北京科技大学工程力学专业获博士学位,现任教授,主要从事矿山固废综合利用及生态环境修复、工程岩体监测及稳定性方面的研究工作。E-mail:zhaok_666666@163.com
