模拟降雨条件下不同土石比例弃土堆置体产流产沙研究

Study on Runoff and Sediment Yield of Spoil-banks with Different Ratios of Soil to Rock under Simulated Rainfall Condition

为研究不同土石比例条件下弃土堆置体水土流失特征之间的差异,以前期概化的4类弃土堆置体中坡顶平台有车辆碾压的弃土堆置类型为研究对象,采用人工模拟降雨试验,研究4种土石比例弃土堆置体在4种降雨强度条件下的产流产沙特征。研究表明:4种土石比例的弃土堆置体的开始产流时间随着砾石含量的增加而缩短;相同土石比例条件下,径流率和侵蚀速率随着降雨强度的增大而增大;相同降雨强度条件下,径流率和侵蚀速率随着土石比例的减小而减小;径流率随着降雨时间的推移在一定范围内呈波动式变化,侵蚀速率随时间推移呈稳定、波动两种变化趋势。不同土石比例弃土堆置体平均径流率、平均侵蚀速率随着砾石含量的增大而增大;总产沙量随着总径流量的增大而增大。

In order to examine the differences of soil erosion characteristic of spoil-banks under different ratios of soil to rock,one of the four different types of spoilbanks was selected as research object based on previous research generalization,rolling compaction by construction machinery at the top of slope.The runoff and sediment characteristics of different ratios of soil to rock under four different rainfall intensities were studied by indoor artificial rainfall simulation experiments.The results showed that the initiative time of runoff of all spoilbanks decreased with the gravel content increasing;in the same ratio of soil to rock,runoff rate and erosion rate increased with the increase of rainfall intensities;in the same rainfall intensity,the runoff rate and erosion rate decreased with the decrease of ratio of soil to rock.The variation of runoff rate in a fluctuating tendency with the rainfall duration,while the erosion rate appeared in two types with the rainfall duration,which were stability and fluctuation.The mean runoff rate,mean erosion rate of different ratios of soil to rock of spoilbanks increased with the increase of gravel content;the total sediment increased with the increase of total runoff.