冲击加载下养护龄期对掺膨润土充填体力学破坏特征研究  

Influence of Curing Age on Mechanical Failure Characteristics of Bentonite Backfill Under Impact Loading

作　　者：张友锋 付玉华[2,3] 余姚[3,4] ZHANG Youfeng;FU Yuhua;YU Yao(School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Application Sciences,Jiangxi University of Science and Technology,Ganzhou 341000,China;Key Laboratory of Mining Engineering in Jiangxi Province,Ganzhou 341000,China;School of Science,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]江西理工大学应用科学学院,江西赣州341000 [3]江西省矿业工程重点实验室,江西赣州341000 [4]江西理工大学理学院,江西赣州341000

出　　处：《有色金属工程》2021年第9期113-122,共10页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(51464015)。

摘　　要：深部开采中爆破、地震波等冲击对不同养护期的胶结充填体稳定性造成破坏,威胁采场安全。为此采用霍普金森杆试验系统对充填体试样进行单次冲击试验,分析爆破荷载下不同龄期掺膨润土全尾砂胶结充填体的动力学特性。结果表明:动态冲击曲线存在多个波峰,养护早期(3、7 d)表现为动态强度硬化(峰值应变0.005左右),后期(14、28 d)为动态强度软化(峰值应变0.002左右);充填体DIF与膨润土掺量正相关,与龄期负相关;养护龄期3-14 d时,动态抗压强度、吸收能、单位体积吸收能随膨润土掺量的增大呈先降后升趋势(10%为临界点),28 d时,两者正相关,养护龄期的延长可以提高充填体吸收能量的能力,增强抗冲击性能;养护早期韧性指数随膨润土掺量的增大而降低,养护后期两者关系表现为正相关且敏感性更高、增幅更显著。In deep mining,the impact of blasting and seismic wave will damage the stability of cemented backfill in different maintenance periods and threaten the safety of stope.In order to analyze the dynamic characteristics of cemented backfill with bentonite at different ages under blasting load,the single impact test of backfill samples was carried out using Hopkinson bar test system.The results show that there are multiple peaks in the dynamic impact curve,the dynamic strength harden(peak strain about 0.005)in the early stage(3,7 d)and the dynamic strength soften(peak strain about 0.002)in the later stage(14,28 d).DIF is positively correlated with bentonite content and negatively correlated with age.When the curing age is 3-14 days,the dynamic compressive strength,absorbed energy and absorbed energy per unit volume decrease firstly and then increase with the increase of bentonite content(10%is the critical point).When the curing age is 28 days,the two are positively correlated.The extension of curing age can improve the energy absorption capacity and enhance the impact resistance of backfill.The correlation between the two indexes is higher in the early curing stage and higher in the later curing stage.

关 键 词：充填体 膨润土掺量 养护龄期 动态强度 吸收能 韧性指数 

分 类 号：TD853.34[矿业工程—金属矿开采]