膨胀土土水特征曲线的研究

对不同地区膨胀土的原状样和重塑样进行了脱湿土水特征曲线试验,并采用VG模型对试验数据进行拟合。结合VG模型拟合的参数,着重分析了矿物成分和孔隙结构对膨胀土土水特征曲线的影响。结果表明:在同一初始干密度下,膨胀土含蒙脱石亲水性矿物越多,脱水速率越慢,持水性能越强;同一土质的重塑样,初始干密度越大,则其进气值越大,脱水速率越慢;在初始干密度相同的条件下,原状样的土水特征曲线与重塑样的不同,其脱水速率较缓慢,残余含水量较高,表现出较强的持水性能。

A Study on Soil Water Characteristic Curve of Expansive Soil

A study on the drying SWCCs of nature specimen and recompacted specimens of expansive soils in different areas is presented.In addition,The experimental data are fitted to VG numerical model.Combined with the fitting parameters obtained from the VG model,the effects of mineral composition and pore structure of the soil on SWCC are analyzed.For the specimens with the same initial soil density,the more montmorillonite content is,the lower the rate of desorption is,and the stronger the capability of retentive water is.For the specimens with the same properties,the higher the initial soil density is,the larger the air-entry value and the lower the rate of desorption is.The SWCC of a recompacted specimen is quite different from that of a nature specimen with the same initial soil density.The rate of the nature specimen is lower than that of the recompacted specimen,and the residual water content of the nature specimen is higher.Nature specimen exhibits a stronger capability of retentive water.