论文部分内容阅读
基于野外原位调查采样、室内人工模拟降雨试验研究道路浮土侵蚀规律.结果表明:浮土产流起始时间和路面侵蚀起始时间随雨强和坡度增大呈递减趋势.路面侵蚀起始时间随浮土厚度增大滞后2~5 min.浮土厚度≤0.5 cm时径流率在产流后2 min趋于稳定,平均径流率随雨强增大而递增,随坡度增大而递减;浮土厚度≥1.0 cm时,径流率在产流后3 min趋于相对稳定,平均径流率随雨强增大呈线性递增,随坡度增大而先递增后递减.侵蚀临界点随坡度和雨强增大呈递减趋势.浮土厚度≤0.5 cm时,侵蚀速率随雨强增大而递增幅度达24.5%~434.4%,坡度8°和16°可达2°和4°的2.4倍;浮土厚度≥1.0 cm时,侵蚀速率在产流开始后9 min左右趋于相对稳定,且随雨强和坡度增大而递增,随坡度增大侵蚀形式发生由“片蚀-细沟侵蚀-溯源侵蚀”的转变.浮土厚度≥1.0 cm时,平均10 min次降雨侵蚀量可达浮土厚度≤0.5 cm的1.3倍,而单独浮土侵蚀时段侵蚀量前者是后者的2.7倍.浮土厚度≤0.5 cm时,侵蚀量与雨强的相关性显著,产流量与坡度的相关性显著;浮土厚度≥1.0 cm时,10 min次降雨产流、产沙与雨强呈显著相关.随浮土厚度增大,浮土侵蚀量在组合侵蚀中所占比例增大,而薄层时主要以道路侵蚀占主导.
The results show that the initial time of runoff generation and the initiation time of pavement erosion decrease with the increase of rainfall intensity and gradient.The onset time of pavement erosion decreases with the increase of rainfall intensity and gradient The thickness of the floating soil increased lag 2 to 5 min, and the runoff rate tended to be stable at 2 min after the floating soil thickness was less than 0.5 cm. The average runoff rate increased with the increase of rainfall intensity and decreased with the increase of slope gradient. cm, the runoff rate tended to be relatively stable at 3 min after the runoff, and the average runoff rate increased linearly with the increase of rainfall intensity and then increased with the increase of slope gradient.The critical point of erosion decreased with the increase of slope and rainfall intensity The trend is that the erosion rate increases 24.5% ~ 434.4% with the increase of rainfall intensity when the thickness of the soil is less than 0.5 cm, the slope of 8 ° and 16 ° can reach 2.4 times of 2 ° and 4 °, The erosion rate tends to be relatively stable at 9th minute after the start of runoff, and increases with the increase of rainfall intensity and gradient. The erosion type changes from “ecliptic erosion - rill erosion” to that of erosion type. When the thickness of the soil is ≥1.0 cm, the average amount of rainfall erosion up to 10 min can reach the thickness of less than 0.5 cm, while the former is 2.7 times that of the latter in the eroded soil alone.The correlation between erosion amount and rainfall intensity is significant when the thickness of the soil is less than 0.5 cm, and the correlation between the flow rate and the slope is significant. The thickness of the soil is ≥1.0 cm, rainfall and runoff occurred 10 min after rainfall, and the correlation between sand production and rainfall intensity was significant. With the increase of soil thickness, the proportion of floating soil erosion increased in combined erosion, while that in thin layer was dominated by road erosion.