不同含沙率浑水膜孔灌三维Green-Ampt入渗模型

通过室内浑水膜孔灌入渗试验,基于三维Green-Ampt模型建立相关的物理模型,研究浑水含沙率对浑水膜孔灌自由入渗的影响.将浑水泥沙对水分入渗的影响概化为水土界面沉降层的减渗作用,以清水膜孔灌为基础,得到不同含沙率下水土界面沉积层减渗作用随时间的变化规律.研究结果表明,沉淀层减渗作用随着浑水含沙率的增大而增大,含沙率越高,减渗作用越明显,同一含沙率浑水减渗作用与时间具有较好的幂函数关系,该减渗作用力最大值出现在土壤水分入渗初期,前30 min减渗作用力明显较大,30 min后减渗作用力变化趋势逐渐减小,100 min后基本趋于稳定状态.该研究为后续浑水膜孔灌自由入渗研究奠定了基础,而且在灌溉理论发展和实际应用方面具有重要的科学价值.

Three-dimensional Green-Ampt infiltration model of muddy water with different sediment concentration under film hole irrigation

The indoor muddy water film hole infiltration test was made and based on the three dimensional Green-Ampt model to establish the relevant physical model to study influence of sediment concentration on free infiltration under muddy water film hole irrigation. The effect of sediment concentration on free infiltration under muddy water film hole irrigation was generalized as infiltration reduction force on the water and soil interface settlement layer. And based on film hole irrigation with clear water, the changing law of the infiltration reduction force on the water and soil interface settlement layer with time was obtained. The results showed that the infiltration reduction force increased with sediment concentration increment. The higher the sediment concentration was, the more obvious the effect about infiltration reduction force was. There was a good power function relationship between the same sediment concentration and the time. The maximum value of reduction force appeared at the initial stage of infiltration. In the first 30 minutes, the reduction force was significantly higher. After 30 minutes, the change trend of reduction force decreased gradually. After 100 minutes, the change trend of reduction force became the steady state. These results lay the foundation for the subsequent study on the free infiltration of muddy film hole irrigation, and are of important scientific value to the development and practical application of irrigation theory.