Soil Water Characteristic Curve (SWCC) is an essential tool to determine the properties of unsaturated geomaterials, including shear strength, permeability and volume change. Although many SWCCs have been measured using laboratory testing, field studies of the subject are very limited. In the current study, six (6) sets of sensors were installed at different depths and locations of a highway embankment. The sensors measured the volumetric moisture content and matric suction of the soil every hour for a period of three three years. The collected data was processed using a Visual Basic (VB) code and the field SWCC was determinedusing Van Genutchen equation. In addition, undisturbed samples were collected and the SWCC was measured in laboratory under different overburden stress. The field and laboratory SWCC were then compared to determine the possibility, accuracy and precision of the field SWCC. Comparison of the SWCCs indicated the optimum depth of sensor installation to be 2.5 m below the existing ground surface. The field SWCC showed considerable compatibility for the range of suction below the Air Entry Value (AEV) but exhibited lower moisture content when compared to the laboratory for suction values greater than AEV. The AEV for laboratory and field SWCC were 110 kPa and 120 kPa, respectively. It was also concluded the normalized water content (i.e. degree of saturation) shows better comparability than the volumetric water content.

土壤水分特征曲线（SWCC）是确定非饱和土工材料特性（包括剪切强度，渗透率和体积变化）的重要工具。尽管已经使用实验室测试测量了许多SWCC，但是对该主题的现场研究非常有限。在当前的研究中，六（6）套传感器安装在高速公路路堤的不同深度和位置。传感器在三年的时间内每小时测量一次土壤的体积水分含量和基质吸力。使用Visual Basic（VB）代码处理收集的数据，并使用Van Genutchen方程确定SWCC字段。另外，收集未受干扰的样品，并在实验室中在不同的上覆应力下测量SWCC。然后将现场SWCC与实验室SWCC进行比较，以确定现场SWCC的可能性，准确性和精度。对SWCC的比较表明，传感器安装的最佳深度应比现有地面低2.5 m。现场SWCC对于低于进气值（AEV）的吸力范围显示出相当大的兼容性，但与实验室相比，吸力值大于AEV时，其水分含量较低。实验室和现场SWCC的AEV分别为110 kPa和120 kPa。还得出结论，归一化水含量（即饱和度）显示出比体积水含量更好的可比性。现场SWCC对于低于进气值（AEV）的吸力范围显示出相当大的兼容性，但与实验室相比，吸力值大于AEV时，其水分含量较低。实验室和现场SWCC的AEV分别为110 kPa和120 kPa。还得出结论，归一化水含量（即饱和度）显示出比体积水含量更好的可比性。现场SWCC对于低于进气值（AEV）的吸力范围显示出相当大的兼容性，但与实验室相比，吸力值大于AEV时，其水分含量较低。实验室和现场SWCC的AEV分别为110 kPa和120 kPa。还得出结论，归一化水含量（即饱和度）显示出比体积水含量更好的可比性。