土体进气吸力值是土-水特征曲线的重要参数,研究非饱和变形土体的水力及力学性质时,需要对其进行预测。结合Van Genuchten(VG)模型与压缩变形条件下土-水特征曲线变化规律,建立了变形土进气吸力值简便预测模型。为验证该模型的合理性,以湖南黏性土为例,采用压力板仪测量其土-水特征曲线试验数据,将不同初始孔隙比黏性土进气吸力值实测值与预测值进行对比。研究结果表明本文方法预测值与实测值吻合较好。此外,采用VG模型对已有非饱和相对渗透系数模型进行简化统一,并进行验证,证明了该方法的简便有效性。研究成果提供了一种理论预测变形土进气吸力值的新方案,为后续的相关研究提供了一种新方法。
Abstract
Air-entry value, as an important parameter of soil-water characteristic curve (SWCC), needs to be predicted in researching the hydraulic and mechanic properties of unsaturated deformable soils. A simple prediction model for the air-entry value of deformable soils was built by combining the Van Genuchten (VG) model with the variation law of SWCC under compression deformation condition. To verify the rationality of the model, experimental SWCC of Hunan clay were measured using pressure plate instrument, which are exploited to further obtain the measured value of air-entry value with different initial void ratios. The measured and predicted values were well consistent, indicating that the proposed model is of good performance. Moreover, VG model is used to simplify and unify the existing models of unsaturated relative permeability coefficient, and the validity and simplicity of this approach is verified.
关键词
进气吸力值 /
黏土 /
土-水特征曲线 /
Van Genuchten模型 /
非饱和渗透系数
Key words
air-entry value /
clay /
soil-water characteristic curve /
Van Genuchten model /
permeability coefficient of unsaturated soils
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