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为揭示在蒸发条件下非饱和土中水分的运动规律,进行了一维土柱非饱和蒸发室内试验,并采用湿/热耦合的非等温渗流方程对蒸发条件下土壤水分的运动规律进行了数值模拟,通过将数值计算结果与试验结果进行对比,验证了湿/热耦合的非等温渗流方程的可靠性,同时发现干土层的形成是引起土壤水分运动形式发生转变的根本原因,即在干土层形成前,土壤内水分的运动以液态流动形式为主;在干土层形成后,干土层以下土壤的水分仍以液态流动形式向上运移,在干土层内则是以水蒸气扩散的形式向大气运动。
In order to reveal the law of water movement in unsaturated soils under the condition of evaporation, a one-dimensional unsaturated soil column experiment was carried out and the non-isothermal seepage equation with wet / heat coupling was used to study the movement of soil moisture under evaporation conditions By comparing the numerical results with the experimental results, the reliability of the wet / heat coupled non-isothermal seepage equation is verified. At the same time, it is found that the formation of dry soil layer is the root cause of the change of soil moisture movement. Before soil formation, the movement of water in the soil is mainly in the form of liquid flow. After the formation of the soil layer, the moisture in the soil below the soil layer is still transported upward by the liquid flow, while in the dry soil layer, the water vapor The form of diffusion to the atmosphere.