岩土力学2025，Vol.46Issue(5)：1356-1367,12.DOI:10.16285/j.rsm.2024.1039
干湿-冻融作用输水渠道膨胀土强度特性及损伤演化规律研究
Strength characteristics and damage evolution law of expansive soil in water conveyance channel under dry-wet and freeze-thaw action
摘要
Abstract
The phenomena of"dry shrinkage and wet expansion"and"frost heave and thaw settlement"in expansive soils in seasonally frozen regions have caused numerous engineering problems.This study focuses on the strength degradation and slope instability in expansive soil water channels of the Northern Xinjiang water supply project.Using drying-wetting and freezing-thawing cycles as experimental conditions,the research includes moisture content monitoring at various depths to analyze soil moisture variation patterns during different stages.Additionally,laboratory experiments are conducted to study the effects of these cycles on non-uniform deformation,strength degradation,and microstructure damage in expansive soils.The results reveal that:1)Under drying-wetting and freezing-thawing conditions,expansive soils at certain depths of the channel foundation exhibit significant moisture content fluctuations.The most significant variations occur during the freeze-thaw phase,establishing a"phase change dynamic zone"within the expansive soil.2)Drying-wetting and freezing-thawing cycles cause significant microstructural damage in expansive soils,marked by continuous crack development and expansion with increasing cycle frequency.The soil experiences persistent"dry shrinkage and wet expansion"and"frost heave and thaw settlement"effects.In the early stages of drying-wetting and freezing-thawing action,expansive deformation significantly contributes to total deformation.However,after a certain number of cycles,both volumetric and expansive soil deformation gradually stabilize.3)Expansive soils exhibit varying degrees of degradation in shear strength and strength parameters.Cohesion degrades more significantly,following an exponential decrease,while the internal friction angle experiences a less pronounced reduction.In the early stages of dry-wet and freeze-thaw cycles,cohesion degradation accounts for 41.2％to 48.6％of the total degradation rate.The significant decrease in soil cohesion leads to shallow landslides in expansive soil slopes of channel foundations,highlighting the crucial role of cohesion in slope instability.关键词
膨胀土输水渠道/干湿-冻融循环/含水率/强度衰减/裂隙扩展Key words
expansive soil drainage channel/dry-wet and freeze-thaw cycles/moisture content/strength attenuation/crack extension分类
土木建筑引用本文复制引用
姜海波,卢燕,李琳,张军..干湿-冻融作用输水渠道膨胀土强度特性及损伤演化规律研究[J].岩土力学,2025,46(5):1356-1367,12.基金项目
"天山英才"培养计划(No.2024TSYCCX0027) （No.2024TSYCCX0027）
国家自然科学基金项目(No.52369021) （No.52369021）
"天山英才"优秀工程师项目(No.2024-2026).This work was supported by the"Tianshan Talents"Training Program(2024TSYCCX0027),the National Natural Science Foundation of China(52369021)and the"Tianshan Talents"Excellent Engineer Training Project(2024-2026). （No.2024-2026）
