考虑初始干密度影响的SWCC预测方法研究

Prediction method for SWCC considering initial dry density

首先研究了3个典型的土水特征曲线模型(van Genuchten模型、Fredlund-Xing模型和Brooks-Corey模型)对不同类型土(黏土、粉土及砂土)的SWCC拟合效果。其次,为了分析各模型对SWCC的干密度相关性拟合效果,讨论了各模型的参数随土体初始孔隙比的变化规律。最后,提出了一种考虑初始干密度影响的SWCC预测方法。方法中假定同一吸力下初始孔隙比与饱和度间存在着线性对应的关系。并且利用该方法对试验结果进行了验证,证实了其合理性。

With the development of urbanization and industrialization, many engineering problems about unsaturated soils are often encountered in practical projects. Engineering accidents related to unsaturated soils have also appeared in highway and railway projects, causing huge economic losses and casualties. Firstly, the fitting results of three SWCC equations(van Genuchten equation, Fredlund-Xing equation and Brooks-Corey equation) on the test results of different types of soils(clay, silt and sand) are studied. Secondly, in order to analyze the fitting effect of each SWCC equation for the dependency of the initial dry density, the variations of model parameters with the initial void ratio of soils in each equation are discussed. Finally, a prediction method for SWCC considering the influence of the initial dry density is proposed, which assumes a linear relationship between the initial void ratio and the saturation under the same suction. This method is verified by the comparison between the predicted and test results.