径流冲刷对高寒高海拔地区高等级公路边坡侵蚀的影响

Impacts of runoff scouring on high-grade highway slope erosion in alpine and high-altitude regions

为阐明高寒高海拔地区高等级公路边坡侵蚀规律,为防治公路边坡水土流失提供理论依据,以青海省共和至玉树公路路基裸露边坡为研究对象,采用野外径流冲刷试验分析了汇流对高寒高海拔地区公路边坡的侵蚀规律与防护策略。分析结果表明:6.0、10.0、14.5L·min^(-1)流量下产流时间较3.5L·min^(-1)流量下产流时间分别提前了23.83、107.63、108.13s,冲刷流量越大,产流时间越短;3.5、6.0、10.0、14.5L·min^(-1)流量下总产沙量分别为14.65、20.42、43.61、32.20kg,产沙量先增大后减小;累积产流量与累积产沙量的关系满足幂函数形式;冲刷流量与侵蚀产沙量呈显著正相关。可见有效减少路面径流是减少高速公路边坡侵蚀量的关键,配套排水措施应具有迅速将路面汇流汇集排出的功能;高寒高海拔地区边坡防护应减少圬工防护措施,在边坡植被恢复时应采用合理的覆盖措施及固土措施。

In order to expound the erosion laws on high-grade highway slope in alpine and high- altitude regions and provide theoretical basis for the prevention and treatment of water and soil loss for highway slope, subgrade bare slope of Gonghe-Yushu Highway in Qinghai Province was chosen as research object, field runoff scouring experiments were carried out to analyze the erosion laws of sink flow on high-grade highway slope in alpine and high-altitude regions, and protection strategy was expounded. Analysis result shows that runoff produce times with flow rates of 6.0, 10.0, 14. 5 L · min^-1 respectively advance by 23.83, 107.63, 108.13 s compared to runoff producing time with flow rate of 3.5 L · min^-1. The bigger scouring flow rate is, the shorter runoff producing time is. Total sediment yields with flow rates of 3.5, 6.0, 10.0, 14. 5 L · min^-1 are 14.65, 20.42, 43.61, 32.20 kg respectively, so the sediment yield first increases then decreases.The relationship between accumulative runoff yield and accumulative sediment yield meets power function form. Scouring flow rate and erosion sediment yield show significant positive correlation. Obviously reducing pavement runoff effectively is the key to decrease highway slope erosion amount, the supporting drainage measures should have the function of collecting and discharging pavement sink flow quickly, masonry protection measures should be reduced in slope protection in alpine and high-altitude regions, and reasonable covering and soil fixing measures should be taken when slope vegetation is in recovery. 3 tabs, 7 figs, 32 refs.