Comparison of windblown sand environmental effects between railway embankment and bridge and its engineering significance

The embankment and bridge are the basic forms of railway lines. To date, no reports have addressed the optimal form to adopt when passing through sandy areas. Therefore, models of railway embankment and bridge were created, and wind tunnel experiments were conducted to compare the differences in wind speed, flow field, sand transport rate, and other wind–sand environmental effects of railway embankment and bridge. Results show that wind speed reduction areas in the upwind and downwind directions were observed for the railway embankment and bridge. In these areas, the extent and degree of wind speed reduction on the embankment were greater than those on the bridge. At the top of the embankment, especially on the windward slope shoulder, an obvious area of wind speed increase was observed. Similarly, a distinct area of wind speed increase was found between the top of the windward side slope shoulder and 3H downwind of the bridge. Within these regions, the range of wind speed increase on the embankment was smaller than that on the bridge, but the degree of increase was greater than that on the bridge. The range of variation in wind speed on the embankment was generally greater than that on the bridge. The wind–sand flow field around the embankment exhibited greater variability than that around the bridge. Moreover, higher wind–sand flow passage rates on the embankment than on the bridge. This study aims to offer recommendations to assist in the route selection, surveying, and design of railways in sandy regions.