张超，汤杰，刘勇锋，等. 冻融循环作用下尾矿宏观力学损伤与微观结构影响研究[J].河南理工大学学报(自然科学版)，doi:10.16186/j.cnki.1673-9787.2025030063

ZHANG C, TANG J, LIU Y F，et al．Study on macro-mechanical damage and microstructural effects of tailings under freeze-thaw cycles［J］.Journal of Henan Polytechnic University( Natural Science) ，doi:10.16186/j.cnki.1673-9787. 2025030063

冻融循环作用下尾矿宏观力学损伤与微观结构影响研究(网络首发)

张超^1,3，汤杰^1,2,3，刘勇锋^4,5，马昌坤³，陈青林^1,2，曾鹏^1,2

（1.江西理工大学 资源与环境工程学院，江西 赣州 341000；2.稀有金属资源安全高效开采江西省重点实验室，江西 赣州 341000；3.中国科学院武汉岩土力学研究所 岩土力学与工程安全全国重点实验室，湖北 武汉 430071；4.重庆大学 资源及环境科学学院，重庆 400044；5.深圳市中金岭南有色金属股份有限公司，广东 深圳 518024）

摘要: [目的] 冻融循环显著影响冻土区尾矿库的结构稳定性，为揭示冻融循环作用下尾矿的宏-微观损伤机制，开展冻融循环作用下尾矿宏观力学损伤与微观结构影响研究。[方法] 通过三轴固结不排水剪切试验、扫描电镜（SEM）及微米CT扫描试验，研究了冻融循环次数对尾矿力学性能及微观结构的影响规律，并建立了宏观力学损伤与微观结构演化的关联机制。[结果] 结果表明：冻融循环导致尾矿宏观力学特性显著劣化，峰值抗剪强度经1次冻融后降幅达13.35%；在5-10次冻融循环阶段，峰值强度下降率为8.8%；10~15次循环阶段降幅减小至3.9%。经15次冻融循环后，黏聚力与内摩擦角分别降低50.9%和59.3%。冻融循环作用导致尾矿颗粒棱角磨损及形态圆润化，形状因子由初始1.38下降至1.34；孔隙分形维度从1.55增至1.64，孔隙率由8.9%上升至16.91%，其中连通孔隙占比从4.68%显著提升至15.51%，研究进一步揭示了孔隙率与抗剪强度呈非线性负相关，内摩擦角随颗粒形状因子增大呈指数增长规律。[结论] 研究结果可为冻土区尾矿库稳定性分析及灾害防控提供参考。

关键词: 尾矿；冻融循环；力学损伤；微观结构

中图分类号：X936

doi: 10.16186/j.cnki.1673-9787.2025030063

基金项目: 国家重点研发计划项目（2023YFC3012200）；国家自然科学基金资助项目（52304155）；江西省自然科学基金资助项目（20232BAB213069）；宜春市重大科技攻关项目（2023ZDKJGG04）

收稿日期：2025-03-28

修回日期：2025-05-19

网络首发日期：2025-06-05

Study on macro-mechanical damage and microstructural effects of tailings under freeze-thaw cycles

Zhang Chao^1,3, Tang Jie^1,2,3, Liu Yongfeng^4,5, Ma Changkun³, Chen Qinglin^1,2, Zeng Peng^1,2

（1. School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China；2. Jiangxi Provincial Key Laboratory of Safe and Efficient Mining of Rare Metal Resource, Ganzhou 341000, Jiangxi, Chian；3. State Key Laboratory of Geomechanics and Geotechnical Engineering Safety, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, Hubei China；4. School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China；5. Shenzhen Zhongjin Lingnan Non-ferrous metal Company Limited, Shenzhen 518024, China）

Abstract: [Objective] Freeze-thaw cycles significantly affect the structural stability of tailings dams in permafrost regions. This study aims to reveal the macro-micro damage mechanisms of tailings materials under freeze-thaw cycling. [Methods] Through triaxial consolidated undrained shear tests, scanning electron microscopy (SEM), and micro-CT scanning, the effects of freeze-thaw cycle frequency on the mechanical properties and microstructural evolution of tailings were investigated. A correlation mechanism between macroscopic mechanical damage and microstructural changes was established. [Results] The results indicate that freeze-thaw cycles significantly degrade the macroscopic mechanical properties of tailings. The peak shear strength decreased by 13.35% after one freeze-thaw cycle. During the 5–10 cycle stage, the peak strength reduction rate was 8.8%, while the reduction rate decreased to 3.9% in the 10~15 cycle stage. After 15 cycles, cohesion and internal friction angle decreased by 50.9% and 59.3%, respectively. Freeze-thaw cycling caused particle edge abrasion and rounding, with the shape factor decreasing from 1.38 to 1.34. The pore fractal dimension increased from 1.55 to 1.64, porosity rose from 8.9% to 16.91%, and the proportion of connected pores surged from 4.68% to 15.51%, The study further reveals a nonlinear negative correlation between porosity and shear strength, while the internal friction angle exhibits an exponential growth trend with increasing particle shape factor. [Conclusion] The research results can provide a reference for the stability analysis and disaster prevention of tailings dams in permafrost regions.

Key words: tailings; freeze-thaw cycles; mechanical damage; microstructure; macro-micro correlation

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