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通过Fluent软件对沙漠公路的风蚀破坏规律进行数值模拟研究。分析公路不同横断面时风沙流扰动、增速、减速、恢复的过程,确定路基(堑)高度、边坡坡率和路面宽度等公路断面设计参数对风沙流扰动的影响,提出沙漠公路路基(堑)风蚀破坏规律。结果表明:路面宽度的改变对路基沿程风速变化影响较小,各特征点处风速变化小于5%。路基(堑)高度和边坡坡率对风沙流扰动的影响较大。随路基(堑)高度增加,风沙流流场的扰动被增强,路基(堑)风蚀破坏越显著,当边坡坡率为1:1时,路基模型高度250 mm时的迎风路肩风速为模型高度60 mm时的1.15倍,其背风坡脚风速降低45%;路堑模型高度250 mm时的背风堑顶风速为模型高度60 mm时的1.05倍,迎风堑脚处风速降低高达80%。建议沙漠公路宜采用中低路基(堑),不宜高填深挖。当路基(堑)高度一定,边坡坡率为1:1.75或1:2时,路基(堑)沿程风速变化平缓,沙漠路肩不易被吹蚀破坏;路堑中堑脚位置处不易出现堆积。其结论与室内风蚀风洞试验结果有很好的一致性。
Fluent software was used to simulate the wind erosion of desert highway. This paper analyzes the process of disturbance, growth, deceleration and recovery of wind and sand flow in different cross sections of highway, and determines the influence of the design parameters of road section such as subgrade (grab) height, slope gradient and pavement width on wind and sand flow disturbance. Cutting) wind erosion damage rules. The results show that the change of pavement width has little effect on the variation of wind speed along the subgrade, and the change of wind speed at each characteristic point is less than 5%. The influence of subgrade (grab) height and slope gradient on the disturbance of wind-blown sand flow is significant. With the increase of subgrade (grab) height, the disturbance of flow field of wind and sand flow is enhanced and the wind erosion damage of subgrade (graben) is more significant. When the slope gradient is 1: 1, the shoulder wind speed of windward road is 250m The wind speed at leeward slope is reduced by 45%. The wind speed at leeward cutting height at cutting model height of 250 mm is 1.05 times of that at model height of 60 mm, and the wind speed at upwind cutting foot is reduced by up to 80%. Proposed desert highway should be used in the low embankment (graben), should not be filled with deep digging. When the subgrade (graben) height is certain and the slope gradient is 1: 1.75 or 1: 2, the wind speed along the embankment (graben) changes gently, and the desert road shoulder is not easily damaged by blown erosion; The conclusion is in good agreement with the indoor wind tunnel test results.