## 3 Results and Discuss  
### Wind Field Evolution Law  
To measure wind speeds at different heights and positions, a wind speed measurement probe was developed and mounted on an adjustable support frame within the wind tunnel test section. This frame enabled vertical and horizontal movement of the probe, as shown in Figure 7. Figure 8 shows the distribution of the 10 cm high embankment and the corresponding wind fields, scaled to a real 3 m high embankment at different startup wind speeds. Measurements were taken at six horizontal positions: 10 cm outside the foot of the windward slope, windward slope top, subgrade center, leeward slope top, leeward slope foot, and 10 cm outside the leeward slope. At each horizontal position, wind speed was measured at vertical intervals corresponding to 0.9 m in the prototype, with a measurement  
Figure 5: Wedge and roughness element. Figure 6: Schematic diagram of test area. The red parallel lines on the embankment indicate the vertical projection of the trapezoidal embankment. point every 3 cm in the model. Due to experimental constraints, the lowest measuring point was set at 0.3 cm above the ground or subgrade surface, corresponding to an actual height of 0.09 m. At a wind speed of 3.9 m/s measured at 30 cm, the starting wind speed at 0.3 cm was 1.86 m/s. Figure 8: The wind field of the embankment. (**a**) 10 cm outside the windward slope foot; (**b**) windward slope foot; (**c**) windward slope top; (**d**) roadbed center; (**e**) leeward slope top; (**f**) leeward slope foot; (**g**) 10 cm outside the leeward slope foot. Figure 7: Flow field measurement. As shown in Figure 8, at any given measurement location, with the increase of starting wind speed, the wind speed at each height increases accordingly, while the overall vertical profile trend remains consistent, with lower wind speeds near the ground, gradually increasing with height until stabilization. At the lowest measurement point (0.3 cm height), 10 cm outside the foot of the windward slope, the foot of the windward slope, the foot of the leafward slope, and 10 cm outside the foot of the leafward slope, the wind speed is low and exhibits minimal change with the increase of the inflow wind speed. The wind speed at the foot of the windward slope, the foot and 10 cm outside the foot of the leafward slope remains below 1 m/s across different inflow wind speeds, with the minimum wind speed recorded at the foot of the leafward slope (0.2 m/s). This suggests that this location is particularly susceptible to snow particle accumulation, which aligns with the findings of subsequent tests. Conversely, the top of the windward slope and the top of the leafward slope exhibit distinct wind acceleration, with wind speeds near the subgrade surface exceeding 2 m/s, followed by an initial increase then a decrease with height until stabilization. At the center of the subgrade, the wind speed near the surface ranges between 1 m/s and 2 m/s, indicating a relatively high potential for snow accumulation in this area, with minimal wind speed variation with increasing height. To clearly compare the wind speeds across the embankment range, measurements were taken at 0.3 cm above the ground, corresponding to 0.09 m at actual height, as depicted in Figure 9. The figure reveals that, under identical wind speed conditions, the wind speed on the windward slope is greater than that on the leafward slope. The lowest wind speed is observed at the foot of the leafward slope, where snow accumulation is most probable. In contrast, the wind speed on the embankment surface is comparatively high, reducing the likelihood of snow accumulation in that area. Figure 10 shows the comparison diagram of the wind speed at 3.3 cm (1 m actual height), 10 cm (3 m actual height), and 20 cm (6 m actual height) near the ground when the inflow wind speed is 5.5 m/s. The abscissa represents the actual corresponding position of each embankment.