竖向应力及干密度对砾石土土-水特征曲线的影响研究

发布时间：2018-08-11 15:05

【摘要】：利用SWC-150 Fredlund土-水特征曲线压力仪,对不同干密度的砾石土进行不同竖向应力作用下的土-水特征试验,探讨了干密度和竖向应力对土-水特征曲线(SWCC)的影响。采用FredlundXing三参数模型对试验所得的土-水特征曲线进行最小二乘法拟合,获得了土-水特征曲线的模型参数,并探讨了其变化规律。随着竖向应力及干密度的增大,模型参数n增大,m减小。除吸湿阶段拟合参数a随干密度略微减小外,其余情况a随竖向应力和干密度密度的增大而增大。结合土-水特征曲线拟合函数,分析研究了竖向应力和干密度对土-水特征曲线的进气值或进水值以及斜率的影响规律,提出了土-水特征曲线的进气值或进水值以及过渡段斜率与竖向应力和干密度的定量关系。结果表明:进气值或进水值与竖向应力和干密度呈线性关系,但吸湿阶段的进水值随干密度变化不明显;土-水特征曲线的斜率与竖向应力呈双曲线关系,与干密度呈直线关系。
[Abstract]:The soil-water characteristic tests of gravel soils with different dry densities under different vertical stress were carried out by using SWC-150 Fredlund soil-water characteristic curve pressure meter. The effects of dry density and vertical stress on soil-water characteristic curve (SWCC) were discussed. The model parameters of soil-water characteristic curve were obtained by using FredlundXing three-parameter model to fit the soil-water characteristic curve by least square method, and the variation law of soil-water characteristic curve was discussed. With the increase of vertical stress and dry density, the model parameter n increases and decreases. Except for the moisture absorption stage fitting parameter a decreases slightly with the dry density, the other case a increases with the increase of vertical stress and dry density. Based on the fitting function of soil-water characteristic curve, the influence of vertical stress and dry density on the inlet value, inlet value and slope of soil-water characteristic curve are analyzed and studied. The quantitative relationship between the inlet and inlet values of soil-water characteristic curve and the slope of transition section with vertical stress and dry density is presented. The results show that the inlet air value or influent value has a linear relationship with vertical stress and dry density, but the influent value of moisture absorption stage does not change obviously with dry density, and the slope of soil-water characteristic curve is hyperbolic with vertical stress. The relationship between dry density and dry density is linear.
【作者单位】：四川大学水力学与山区河流保护国家重点试验室;四川大学水利水电学院;昆明理工大学津桥学院;
【基金】：教育部博士点基金(博导类)资助项目(No.20100181110076)
【分类号】：TU43

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