摘要
为研究养护龄期对尾砂胶结充填体力学特性及损伤规律的影响,在RMT-150C岩石力学试验系统上对不同养护龄期下尾砂胶结充填体开展了单轴压缩试验;获得了不同养护龄期胶结充填体的力学参数及应力应变曲线,详细分析了充填体在试验过程中的破坏机理,推导构建了不同养护龄期胶结充填体的损伤演化和损伤本构方程。试验结果表明:弹性模量、割线模量与养护龄期呈正相关性,且均遵循指数函数曲线增长规律,灰砂比较低时,养护龄期对充填体平均刚度的强化效应更为明显;峰值变形模量与韧性指数随养护龄期增长均呈指数函数曲线增长,且灰砂比越大,养护龄期对充填体的增韧效果越显著;充填体的峰值应力损伤值与养护龄期具有良好的指数正相关性;随着养护龄期延长,损伤值总体增长越慢,侧面说明了养护龄期越短的胶结充填体产生破坏的过程更加突然,体现出了养护龄期短的胶结充填体承载能力低的特点;基于损伤值与应力值的变化规律可知,单轴加载下充填体的损伤破坏演化机制可划分为初始损伤、损伤稳定发展、损伤加速及损伤破坏4个阶段。
In order to study the effect of curing age on the mechanical properties and damage law of tailings cemented backfill,uniaxial compression tests were carried out on the cemented tailings backfill with different curing ages by RMT-150C rock mechanics test system.The mechanical parameters and stress-strain curves of the cemented backfill were obtained,and the damage mechanism of the backfill during the test was analyzed in detail.The damage evolution and damage constitutive equations of the cemented backfill under different curing ages were derived.The test results are concluded as follows.Firstly,the elastic modulus and secant modulus are positively correlated with the curing age,and both follow the exponential function curve growth law.When the cement-sand ratio is low,the strengthening effect of curing age on the average stiffness of backfill is more obvious.Secondly,the peak deformation modulus and toughness index increase exponentially with the increase of curing age,and the larger the cement-sand ratio is,the more significant the toughening effect of curing age on the backfill is.Thirdly,the peak stress damage value of the filling body has a good exponential correlation with the curing age.Fourthly,with the increase of the curing age,the overall damage value grows slower.It indicates that the shorter the curing age,the more severe the damage process of the cemented filling body is,which reflects the low bearing capacity of the cemented filling body under short curing age.Finally,Based on the change law of damage value and stress value,it can be known that the damage evolution mechanism of the backfill under uniaxial loading can be divided into four stages,including initial damage,stable damage development,damage acceleration and damage.
作者
谷中元
秦宏宇
于灯凯
GU Zhongyuan;QIN Hongyu;YU Dengkai(Changchun Institute of Engineering,Changchun,Jilin 130000,China)
出处
《矿业研究与开发》
CAS
北大核心
2020年第10期85-92,共8页
Mining Research and Development
基金
吉林省科技发展计划项目(20200101103FG)
吉林省教育厅“十三五”科研规划项目(jjkh20180994sk).
关键词
尾砂胶结充填体
养护龄期
力学性能
损伤特性
单轴压缩
Tailings cemented backfill
Curing age
Mechanical properties
Damage law
Uniaxial compression
