水利水电科技进展2025，Vol.45Issue(4)：45-53,84,10.DOI:10.3880/j.issn.1006-7647.2025.04.007
干湿-冻融循环作用下北疆膨胀土力学特性的劣化机制及其非线性模型研究
Deterioration mechanism and non-linear model of mechanical properties of expansive soil in northern Xinjiang under dry-wet-freeze-thaw cycle conditions
摘要
Abstract
In order to further explore the failure mechanism of canal slope,triaxial tests and scanning electron microscope(SEM)tests were conducted on expansive soil in northern Xinjiang under dry-wet-freeze-thaw cycle conditions,the physical deterioration mechanism of expansive soil was studied from macroscopic,mesoscopic and microscopic perspectives,and the influence of dry-wet-fueeze-thaw cycles on the parameters of the Duncan-Zhang E-B model was analyzed.The results show that under the dry-wet-freeze-thaw cycle conditions,the stress-strain curve of the expansive soil exhibits a hardening type,and the volumetric strain curve shows shear shrinkage characteristics.The cohesion decreases nonlinearly with the increase of the number of cycles,with the most significant reduction occurring during the first cycle,and it tends to be stable after seven cycles.The internal friction angle changes little and remains almost constant.During the cyclic process,cracks in the expansive soil develop from both ends to the center,the internal crack grids gradually converge and form a crack core in the weak area of the soil body,and the overall failure surface gradually develops from an initial"Y"shape or"X"shape to a"claw-shaped"longitudinal penetration damage surface.The cyclic action caused the aggregated structure of the soil to break down and reorganize into a loose flocculent structure,the intergranular pores increase,and the clay particles gradually peel off and detach,resulting in the structural damage of the soil body.The weakening of the intergranular bonding effect is the main reason for the decrease in cohesion.The cyclic action has significant influence on the Duncan-Zhang E-B model parameters n,K,and Kb.When the number of cycles is more than three,the changes in these parameters are relatively small.Exponential function fitting indicates a good correlation between these parameters and the number of cycles.关键词
干湿-冻融循环/膨胀土/强度劣化/裂隙/邓肯-张模型/北疆Key words
dry-wet-freeze-thaw cycle/expansive soil/strength deterioration/fissure/Duncan-Chang model/northern Xinjiang分类
建筑与水利引用本文复制引用
张凌凯,徐浩振,丁旭升,崔子晏..干湿-冻融循环作用下北疆膨胀土力学特性的劣化机制及其非线性模型研究[J].水利水电科技进展,2025,45(4):45-53,84,10.基金项目
新疆维吾尔自治区中央引导地方科技发展资金项目(ZYYD2024CG20) （ZYYD2024CG20）
2022年自治区杰出青年科学基金项目(2022D01E45) （2022D01E45）
2022年自治区重点研发任务专项资金项目(2022B03024-3) （2022B03024-3）
2023年度自治区"天山英才"培养计划青年拔尖人才项目(2023TSYCJU0007) （2023TSYCJU0007）
