采用蒸汽平衡法测定了4种温度（T=5、25、40、60 ℃）条件下WhatmanNo.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。Toexplore the variation of water retention capacity of expansive soil atdifferent temperatures

the calibration curves of Whatman No.42 filter paperwere measured by vapor equilibrium method at 5

25

40 ℃ and 60 ℃

and the bilinear calibration equation consideringtemperature effect was established. The results show that the water retentioncapacity of the filter paper decreases with the increase of temperature

andthe effect on the high suction section of calibration curve is weaker than thelow suction section. On this basis

Nanning expansive soil istaken as the research object

and the soil-water characteristic curves ofNanning expansive soil at different temperatures are measured by filter papermethod. It is found that the water retention capacity of Nanning expansive soildecreases with the increase of temperature

but the influence of temperaturedepends on matric suction

especially when it is above 40 MPa

thewater-retention capacity of Nanning expansive soil remains unchanged withtemperatures. To probe into the microscopic mechanism of the change of waterretention capacity of Nanning expansive soil under temperature

some sampleswere selected for mercury intrusion porosimetry test and adsorption bound watertest. Based on the test results

the microscopic mechanism of water retentioncapacity change of Nanning expansive soil was analyzed from the physicalmechanism of the interaction between each phase and each phase interface.