非饱和土的土水特征曲线测试方法研究

Hydrus-1D Inversion of Unsaturated Soil Hydraulic Parameters

土水特征曲线是非饱和土的重要的水力特性参数,它在分析非饱和土强度及边坡稳定等问题时起到重要作用。对粉土试样开展了一步流动试验得出溢出水量随时间的关系曲线,利用Hydrus-1D水分运移模型对该曲线进行拟合并得出相关参数,根据这些参数反算得出试样的土水特征曲线并和实测数据进行了对比。结果表明,该方法能较好的拟合实测的溢出水量随时间变化的关系曲线,通过模型得出的土水特征曲线和实测值比较接近,证实了该方法的可靠性。通过与传统的测试方法相比较,该方法能够节约大量的时间。因此,通过Hydrus-1D水分运移模型反演分析非饱和土的土水特征曲线的方法是快速有效的。

The soil-water characteristic curve is one of the hydraulic properties of unsaturated soils which play a crucial role in analy-zing the processes related to unsaturated soils ,such as the problem of strength of unsaturated soil and slope stability .The curves of outflow with time are observed from one-step outflow experiments .The parameters which are evaluated by using the Hydrus-1D wa-ter transport model are used to determine the soil-water characteristic curve and the hydraulic conductivity function .By comparing the measured data ,it shows that the method can fit the observed curves of outflow with time correctly which confirm the reliability of the method .The difference of soil water characteristic curves between the estimated and measured is small .In addition ,compared with the traditional methods the method enables experiments to complete in a short period of time .Therefore ,the method which de-termines the hydraulic parameters of unsaturated soils by Hydrus-1D water transport model is feasible .