不同温湿路径下压实黏土的土-水和动力响应特性  

Soil-water characteristics and dynamic responses of compacted clay under different moisture and temperature paths

作　　者：韩仲 张琳 丁鲁强 邹维列[1] 冯怀平[3] 应镇谦 HAN Zhong;ZHANG Lin;DING Luqiang;ZOU Weilie;FENG Huaiping;YING Zhenqian(School of Civil Engineering,Wuhan University,Wuhan 430072,China;School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]河北工业大学土木与交通学院,天津300401 [3]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,河北石家庄050043

出　　处：《岩土工程学报》2024年第12期2591-2601,共11页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52378365,52308346);中央引导地方科技发展资金项目(236Z5409G);中国博士后科学基金项目(2022M720986)。

摘　　要：以黑龙江黏土为研究对象,按照3种不同的路径(干湿—冻融路径、冻融—干湿路径、交叉的干湿冻融路径)施加了温湿作用,对比分析了不同温湿路径下压实黏土的微观结构、土-水特性、累积塑性应变(ε_(p))和回弹模量(MR)的演化规律。结果表明:①温湿作用后土体内宏观孔隙发育,微观孔隙收缩,持水能力降低,脱湿速率增大。多次温湿作用后,经不同温湿路径的试样具有相似的微观孔隙结构及土-水特性;②ε_(p)和M_(R)在高含水率下对湿度变化(包括含水率w和吸力s)更敏感。冻融循环后,ε_(p)对湿度的敏感性显著增加,MR对湿度的敏感性显著降低;③温湿作用后土体的M_(R-s)关系呈现非线性特征,M_(R-w)关系呈现线性特征。长期温湿作用后,不同温湿路径对ε_(p)和MR的影响差异较小;④基于非饱和土力学原理建立模型,较好地预测了不同温湿路径下MR随湿度的变化规律。The microstructure,soil-water characteristics,accumulative plastic strain(ε_(p))and resilient modulus(M_(R))of a compacted Heilongjiang clay are compared.The specimens are imposed with three different moisture(wetting-drying,WD)and temperature(freeze-thaw,FT)paths(i.e.,WD-FT,FT-WD and interlaced FTWD histories).The experimental results show that:(1)After moisture-temperature(M-T)actions,the structural pores develop while the textural ones shrink,which leads to reduction in the water retention capacity and increase in the desaturation rate.After M-T effects are stabilized,the microstructure and soil-water characteristics of the specimens with different M-T paths become similar.(2)Under at high moisture content(w),ep and M_(R)are more sensitive to moisture changes(including w and suction s).After FT cycles,ε_(p)becomes more sensitive while M_(R)becomes less sensitive to moisture changes.(3)After M-T effects,the M_(R)-s relationships are nonlinear while the M_(R)-w relationships are linear.The different M-T paths do not generate differences inep and M_(R)when the M-T effects are stabilized.(4)A model based on the mechanics of unsaturated soils is used to rationally predict the variation of M_(R)with w and s for the specimens with different M-T paths.

关 键 词：压实黏土 温湿路径 动力响应 土-水特性 微观结构 

分 类 号：TU43[建筑科学—岩土工程]