论文部分内容阅读
土壤胀缩是土壤在干燥、湿润交替变化过程中所表现出的土壤容积随含水量改变的现象。本文通过测定4种土壤脱水和吸水过程中的土柱高度和直径的变化,分析了胀缩过程中土壤容积与含水量的关系及土壤的胀缩特征。结果显示:三直线模型能够很好地拟合4种土壤的收缩、膨胀过程;土壤收缩、膨胀曲线各段的特征值均小于1,这说明土壤胀缩过程中土壤容积的变化速率小于含水量的变化速率;4种土壤胀缩过程中几何因子rs大于1而小于3,且收缩初期几何因子rs等于1,表明土壤的胀缩是各向异性的,并且在土壤收缩的最初阶段只有垂直收缩。
Soil shrinkage and shrinkage is the phenomenon that soil volume changes with water content during the process of dry and wet alternation. In this paper, the relationship between soil volume and water content and the expansion and contraction of soil were analyzed by measuring the change of soil column height and diameter during the dehydration and water absorption of four kinds of soils. The results show that the three-line model can well fit the shrinkage and expansion processes of four kinds of soil. The values of soil contraction and expansion curve are less than 1, indicating that the rate of change of soil volume during the process of soil expansion and contraction is less than the water content The geometric factors rs of the four soil processes are greater than 1 and less than 3, and the initial shrinkage factor rs is equal to 1, indicating that the soil is anisotropic in its expansion and contraction and only has vertical shrinkage in the initial stage of soil shrinkage .