养护龄期、水泥掺量和围压对胶结充填体饱和渗流特性和三轴压缩行为影响
Effect of curing age,cement content and confining pressure on the saturated hydraulic conductivity and triaxial compressive behavior of cemented tailings backfill
徐文彬 1吴蔚律 1刘斌1
作者信息
- 1. School of Energy and Mining Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China
- 折叠
摘要
渗流特性是影响地下采场胶结充填体稳定性的重要指标.本文以胶结充填体为研究对象,采用室内实验和微观分析相结合的方法,系统分析和讨论了三轴压缩和非压缩条件下,不同水泥掺量(2%、3%、5%)、养护龄期(3d、7d、28 d)和围压(100、200、300、400 kPa)对胶结充填体渗流特性的影响.研究结果表明:胶结充填体的静态渗流系数随着养护龄期和水泥掺量的增加呈非线性下降趋势,围压升高会对充填体的渗流速率产生抑制作用;胶结充填体的动态渗流系数与其变形过程密切相关;充填体在三轴压缩过程中,随着轴向应变的增加,充填体的渗流系数先降低后升高;围压和水泥掺量越大,充填体的动态渗流系数越小;充填体的体积应变表现为先收缩后膨胀,体积应变演化阐释了动态渗透系数时效性.研究结果可为井下充填采场排水以及充填体稳定性分析与设计提供指导.
Abstract
Hydraulic conductivity is a vital parameter that affects the mechanical stability of cemented tailings backfill(CTB)after placement into underground stope.Triaxial seepage tests were conducted on the CTB samples to investigate the effects of the cement content(2%,3%and 5%),curing age(3,7 and 28 d)and confining pressure(100,200,300 and 400 kPa)on the evolution of hydraulic conductivity.In addition,the change of hydraulic conductivity with axial strain during triaxial compression was revealed as well.The results show that the static hydraulic conductivity of CTBs shows a non-linear decrease with increasing of curing age length and cement content,and the confining pressure plays a negative effect on the static hydraulic conductivity.The dynamic hydraulic conductivity is closely associated with the deformation of CTB during the triaxial compression.The hydraulic conductivity of CTB shows a decrease firstly,but increases with further increase in the axial strain.The volumetric strain curves show volume shrinkage at first and subsequently expansion,which can be used to explain the dynamic hydraulic conductivity evolution under triaxial compression.The results can provide guide reference for backfill strength and drainage design.
关键词
尾砂胶结充填/渗流系数/养护龄期/水泥掺量/三轴压缩Key words
cemented tailings backfill/hydraulic conductivity/curing age/cement content/triaxial compression引用本文复制引用
基金项目
National Natural Foundation of China(51504256)
Yueqi Young Scholar Project,China(800015Z1185)
Fundamental Research Funds for the Central Universities,China(2022YJSNY06)
出版年
2023
NETL
NSTL
维普
万方数据