摘要
为了研究尾砂胶结充填体在三点弯曲作用下的蠕变特性,通过三点弯曲试验测得灰砂比为1∶4、1∶6、1∶8的充填体抗折强度,在此基础上进行了分级加载三点弯曲蠕变声发射试验,研究了不同灰砂比、不同荷载水平下尾砂胶结充填体的三点弯曲蠕变特性和声发射特征。研究结果表明:(1)尾砂胶结充填体三点弯曲蠕变全过程表现为减速、稳态和加速三个蠕变阶段,灰砂比为1∶4和1∶6的充填体在第7级荷载水平步入加速蠕变阶段,灰砂比为1∶8的充填体在第5级荷载水平步入加速蠕变阶段。(2)随着荷载水平的增加,尾砂胶结充填体瞬时蠕变量、蠕变变形量、蠕变速率持续增大,灰砂比越大的充填体蠕变变形能力越弱。(3)随着荷载水平的增加,声发射撞击数、振铃计数、能量数值总体呈先下降后上升趋势,灰砂比为1∶4、1∶6的充填体在第4级荷载水平达到最小值,灰砂比为1∶8的充填体在第3级荷载水平达到最小值。灰砂比越大的充填体,蠕变断裂破坏时所产生的声发射信号越多,声发射能量越大。
In order to study the creep characteristics of tailings cemented backfill under three-point bending,the flexural strength of backfill with cement-sand ratio of 1∶4,1∶6 and 1∶8 was measured by three-point bending test.On this basis,the acoustic emission test of three-point bending creep with graded loading was carried out,and the three-point bending creep characteristics and acoustic emission characteristics of tailing cementeds backfill under different cement-sand ratio and different load levels were studied.The results are concluded as follows.Firstly,the whole process of three-point bending creep of tailings cemented backfill is characterized by three creep stages:deceleration,steady state and acceleration.The backfill with cement-sand ratio of 1∶4 and 1∶6 enters the accelerated creep stage at the 7th load level,and the backfill with cement-sand ratio of 1∶8 enters the accelerated creep stage at the 5th load level.Secondly,with the increase of load level,the instantaneous creep amount,creep deformation amount and creep rate of tailings cemented backfill continue to increase.The larger the cement-sand ratio,the weaker the creep deformation ability of the backfill.Finally,with the increase of load level,the impact number,ringing count and energy value of acoustic emission decrease first and then increase.The backfill with cement-sand ratio of 1∶4 and 1∶6 reaches the minimum value at the 4th load level,and the backfill with cement-sand ratio of 1∶8 reaches the minimum value at the 3rd load level.The larger the cement-sand ratio of the backfill,the more acoustic emission signals and the greater the acoustic emission energy generated during creep fracture failure.
作者
刘光卓
曾鹏
赵奎
钟文
龚囱
熊良锋
LIU Guangzhuo;ZENG Peng;ZHAO Kui;ZHONG Wen;GONG Cong;XIONG Liangfeng(School of resources and environmental engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China;Jiangxi Provincial Key Laboratory of Mining Engineering,Ganzhou,Jiangxi 341000,China)
出处
《矿业研究与开发》
CAS
北大核心
2024年第2期41-46,共6页
Mining Research and Development
基金
国家重点研发计划资助项目(2017YFC0804601)
江西省青年井冈学者计划项目(QNJG2019054)
江西省博士后择优资助项目(2020KY39)。
关键词
三点弯曲
蠕变
尾砂胶结充填体
声发射
Three-point bending
Creep
Tailings cemented backfill
Acoustic emission
