黄土路基边坡的雨水侵蚀特征

Characteristics of Rainwater Erosion of Loess Subgrade Slope

以水力学、泥沙运动学为基础,从水流对土颗粒做功的角度探讨了坡面流的携砂能力,得出了雨水最大冲刷量的理论坡度值。通过室内模拟降雨对黄土边坡的冲刷试验,得出了坡度比、降雨强度等因素对坡面流含泥量及冲刷总量的关系。试验再现了雨水侵蚀黄土边坡的过程,总结描绘出侵蚀沟在黄土路基边坡纵断面上的分布规律,以及边坡平台与坡面流的相互作用,发现近坡脚侵蚀沟发育最严重,呈现逆源侵蚀的特点。通过分析试验数据,得出本次试验黄土边坡的最大冲刷坡度为41.1°,与理论值接近。

Based on hydraulics and sediment kinematics,the sand carrying capacity of the slope flow was discussed from the perspective of water flow on the work of soil particles,and the theoretical slope value of the maximum flushing amount of rainwater was obtained.Through the laboratory test of simulated rainfall erosion of the loess slope,the relationship between slope ratio,rainfall intensity and other factors on the mud content and total amount of erosion on the slope surface was found.The experiment reproduces the process of rainwater erosion of the loess slope,and summarizes the distribution of the erosion ditch on the longitudinal section of the loess subgrade and the interaction between the slope platform and the slope flow.It is found that the development of the near-slope foot erosion ditch is the most serious,showing the characteristics of reverse source erosion.By analyzing the test data,it is concluded that the maximum scouring angle of the loess slope in this test is 41.1°,which is close to the theoretical value.