模拟降雨条件下不同颗粒级配工程弃土的侵蚀实验

以沈阳市天柱山附近的工程弃土为研究对象,利用室内人工模拟降雨方法,对25°坡面上不同土壤颗粒级配的工程弃土在1.0、1.5和2.0 mm/min 3种不同降雨强度作用下产生的径流量和产沙量进行分析研究.结果表明:1)试验所用Ⅰ-Ⅴ组土样随着降雨强度的增加(从1.5增加到2.0 mm/min),累积产沙量分别增加12.55、7.56、12.00、8.81和10.41 g,而在3种降雨强度作用下,3个最大与最小累积产沙量差值分别为6.39、11.64和13.78 g；2)产沙量随细度模数的增大而减少；3)在降雨强度、坡度、降雨历时等因子一定的条件下,土壤颗粒级配对径流量的影响比较小,不同颗粒级配土壤的累积径流量差异不明显.

Erosion experitment of construction spoil with different particle gradation under simulated rainfall condition

To reveal the relationship between rainfall and different particle gradation of brown soil,this study selected construction spoil as experimental material from Tianzhu mountain in Shenyang.Construction spoil of different particle gradation were deposited in the same slope of 25°,runoff and sediment production were observed and analyzed under three different rainfall intensities,1.0,1.5 and 2.0 mm/min using indoor artificial simulation of rainfall.Results shows: 1) With increasing rainfall intensities(from 1.0 to 1.5 mm/min),the cumulative sediment yield of five kinds of soil samples increased 12.55,7.56,12.00,8.81 and 10.41 g respectively;while under three rainfall intensities(1.0,1.5 and 2.0 mm/min),the difference of the three most and least cumulative sediment yield were 6.39,11.64 and 13.78 g.2) The sediment production decreased as the fineness modulus increased.3)When the rainfall intensity,slope and rainfall duration were stable,particle size distribution had little effect on runoff,and the cumulative runoff of different particle size distribution had relatively small differences.