摘要
采用蒸汽平衡法测定了4种温度(T=5、25、40、60℃)条件下Whatman No.42滤纸的率定曲线,建立了考虑温度影响的双线性率定曲线方程,发现滤纸的持水性能随温度升高而降低,且温度对率定曲线高吸力段滤纸持水性能的影响要弱于低吸力段。在此基础上,以南宁膨胀土为研究对象,使用滤纸法测定了不同温度作用下膨胀土试样的土-水特征曲线。试验结果表明,随着温度的升高,膨胀土持水性能下降,但温度的影响幅度会随着吸力的增大而减弱,当基质吸力达到40 MPa时,不同温度下试样的体积含水率并没有明显变化,即此时温度对膨胀土的持水性能变化几乎无影响。为解释上述宏观现象,选取部分试样进行了压汞试验和吸附结合水试验,并根据试验结果从土体中各相及各相界面相互耦合作用的物理机制角度阐述了南宁膨胀土持水性能的温度效应及微观机制。
To explore the variation of water retention capacity of expansive soil at different temperatures,the calibration curves of Whatman No.42 filter paper were measured by vapor equilibrium method at 5,25,40℃and 60℃,and the bilinear calibration equation considering temperature effect was established.The results show that the water retention capacity of the filter paper decreases with the increase of temperature,and the effect on the high suction section of calibration curve is weaker than the low suction section.On this basis,Nanning expansive soil is taken as the research object,and the soil-water characteristic curves of Nanning expansive soil at different temperatures are measured by filter paper method.It is found that the water retention capacity of Nanning expansive soil decreases with the increase of temperature,but the influence of temperature depends on matric suction,especially when it is above 40 MPa,the water-retention capacity of Nanning expansive soil remains unchanged with temperatures.To probe into the microscopic mechanism of the change of water retention capacity of Nanning expansive soil under temperature,some samples were selected for mercury intrusion porosimetry test and adsorption bound water test.Based on the test results,the microscopic mechanism of water retention capacity change of Nanning expansive soil was analyzed from the physical mechanism of the interaction between each phase and each phase interface.
作者
曾召田
崔哲旗
孙德安
姚志
潘斌
ZENG Zhao-tian;CUI Zhe-qi;SUN De-an;YAO Zhi;PAN Bin(Guangxi Key Laboratory of Geotechnical Mechanics and Engineering,Guilin University of Technology,Guilin,Guangxi 541004,China;Department of Civil Engineering,Shanghai University,Shanghai 200444,China;Third Institute Geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources,Lanzhou,Gansu 730050,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第8期2177-2185,共9页
Rock and Soil Mechanics
基金
国家自然科学基金(No.41962014,No.42167020)
广西自然科学基金(No.2023GXNSFAA026187)。
关键词
膨胀土
持水性能
温度效应
微观机制
滤纸法
expansive soil
water retention capacity
temperature effect
microscopic mechanism
filter paper method
作者简介
第一作者:曾召田,男,1981年生,博士,教授,博士生导师,主要从事环境岩土工程方面的研究工作。E-mail:zengzhaotian@163.com;通讯作者:孙德安,男,1962年生,博士,教授,博士生导师,主要从事非饱和土力学方面的研究工作。E-mail:sundean@shu.edu.cn。
