尾砂粒级、灰砂比和料浆浓度对充填体力学性质影响研究  

Influence of tailings particle size,cement-sand ratio,and slurry concentration on mechanical properties of tailings backfill

作　　者：李永密 金爱兵[2] LI Yongmi;JIN Aibing(National Mine Safety Administration,Beijing 100713,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]国家矿山安全监察局,北京100713 [2]北京科技大学土木与资源工程学院,北京100083

出　　处：《中国安全生产科学技术》2024年第11期21-29,共9页Journal of Safety Science and Technology

基　　金：国家自然科学基金项目(52174106)。

摘　　要：为研究尾砂粒级、灰砂比和料浆浓度对充填体力学性质的影响程度,采用基于数字图像相关技术的单轴压缩试验分析不同粒级尾砂充填体的力学特性和应变场分布特征,利用扫描电子显微镜获取充填体微观结构特征,揭示尾砂粒级对充填体力学特性的影响机制。研究结果表明:随着尾砂粒级增大,应力-应变曲线的弹性阶段延长、塑性阶段缩短;裂隙演化过程可分为微裂隙闭合、微裂隙发育、微裂隙扩展和裂隙贯通4个阶段,充填体开裂程度在峰值应力前较小、峰值应力后较大;随着尾砂粒级增大,充填体面孔隙率降低,C-S-H凝胶数量逐渐增多;多因素作用对充填体强度影响强弱为:尾砂粒级与灰砂比>尾砂粒级与料浆浓度>料浆浓度与灰砂比。研究结果可为矿山井下充填参数设计提供理论指导。In order to study the influence of tailing particle size,cement-sand ratio,and slurry concentration on the mechanical properties of cemented tailings backfill(CTB),the uniaxial compression tests based on digital image related technologies were conducted to analyze the mechanical properties and strain field distribution characteristics of CTB with different particle sizes.The scanning electron microscope was used to obtain the microstructure characteristics of CTB,so as to reveal the influence mechanism of tailings particle size on the mechanical properties of CTB.The results show that with the increase of tailings particle size,the elastic stage of stress-strain curve is prolonged,and the plastic stage is shortened.The evolution process of fracture can be divided into four stages:closure,development,expansion and penetration,and the cracking degree of CTB is smaller before the peak stress and larger after the peak stress.With the increase of tailings particle size,the surface porosity of CTB decreases,and the number of C-S-H gel increases gradually.The influence degree of multiple factors on the strength of CTB is as follows:tailings particle size and cement-sand ratio>tailings particle size and slurry concentration>slurry concentration and cement-sand ratio.The research results can provide theoretical guidance for the design of backfill parameters in underground mines.

关 键 词：尾砂粒级 胶结充填体 力学特性 微观结构 DIC技术 

分 类 号：X936[环境科学与工程—安全科学]