Abstract:

Wind erosion failure law of aeolian soils subgrade and the influence of the different subgrade design cross-sections on wind-blown sand are studied through interior wind erosion wind tunnel test. The wind-blown sand’s process of disturbance, accelerating, speed-down, and recovery in different subgrade cross-sections are studied; the characteristic of wind-blown sand field around subgrade are summarized for subgrade defect and subgrade non-defect. The influence factor on the wind erosion failure of aeolian soils subgrade is analyzed. The results indicate that the effect of subgrade height and slope gradient on the wind-blown sand field is obvious; while the change of subgrade’s width can’t affect the flow field notably. The disturbance to the flow field enhances with the increase of subgrade’s height, blow erosion on the top of the windward slope is severe; and heap erosion destroy is brought to the bottom of leeward slope. When subgrade model height is 250 mm compared with that of 60 mm, the wind speed on the top of windward slope increase 1.13 times and decrease 2.53 times at bottom of leeward slope for the certain side slope rate. So subgrade height should less than 2.5m to avoid the wind erosion failure of desert highway. Further, the influence of the different side slope rate on wind-blown sand is analyzed for the certain subgrade height. The change of the wind speed is unconspicuous when the side slope gradient is 1:1.75, the wind erosion failure of aeolian soils subgrade is neglectable.

Key words: geoenvironmental engineering, desert highway, wind-blown sand, wind erosion, subgrade sections, interior wind erosion wind tunnel test