不同干密度下土水特征曲线模型参数确定简化方法

A Simplified Method for Determining the Model Parameters of Soil-Water Characteristic Curve under Different Dry Densities

为避免获得土水特征曲线模型参数的复杂测试过程,提出了一种确定模型参数的简化方法。通过使用Gardner,Van Genuchten,Fredlund&Xing 3种模型对土水特征曲线数据拟合,发现3种模型相关系数除干密度为1.50,1.60,1.71 g/cm^3时Gardner模型的决定系数R^2为0.940,0.949,0.953,其他相关系数均超过了0.96,拟合效果较好。对Gardner模型和Van Genuchten模型中各参数进行分析,发现它们与干密度之间有良好的相关性,干密度和各模型参数之间成线性、二次函数和幂函数关系,并据此提出了由干密度确定模型参数的简化方法,具有一定的实用性,期望能为工程提供参考。

Soil-water characteristic curve (SWCC) was fitted by Gardner’s model,Van Genuchten’s model,and Fredlund & Xing’s model to find that in addition to the correlation coefficient R^2 (0.940,0.949,0.953) fitted by Gardner’s model when dry density equals 1.5 g/cm^3,1.6 g/cm^3,and 1.71 g/cm^3,the correlation coefficients fitted by other models all exceed 0.96,indicating a good fitting effect.The parameters in Gardner’s model and Van Genuchten’s are of good correlation with dry density.On this basis,a simplified method for determining the model parameters according to dry density is proposed to avoid the complex testing process for obtaining the model parameters.The proposed method is practical and is expected to offer reference for engineering.