Macromechanical damage and microstructural effects of tailings under freeze-thaw cycles
Zhang Chao
Tang Jie
Liu Yongfeng
Ma Changkun
Chen Qinglin
Zeng Peng
Abstract：Objectives 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 mac-roscopic mechanical damage and microstructural changes was established.Results Freeze-thaw cycles sig-nificantly degraded 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 in the 10～15 cycle stage,the reduction rate decreased to 3.9%.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 in-creased markedly from 4.68%to 15.51%.Furthermore,porosity exhibited a nonlinear negative correlation with shear strength,while the internal friction angle showed an exponential increase with particle shape fac-tor.Conclusions These findings provide a scientific basis for stability analysis and disaster prevention of tailings dams in permafrost regions.
Keywords：tailingsfreeze-thaw cyclemechanical damagemicrostructure
Publication Date：2025-11-30
Online Publishing Date：2025-10-22(First online date of this platform, not the publication date of the document)
Pages：9( 9-17 )