Dynamic wind differences in the formation of sand hazards at high- and low-altitude railway sections

Compared with the railway sand hazards at low-altitude regions, whether the railway sand hazards at high-altitude regions have been aggravated or mitigated, which is not conducive to targeted control of sand hazards, is currently unclear. Honglianghe River section of Qinghai-Tibet Railway and Danghe River section of Dunhuang-Golmud Railway were selected as the typical representatives of high- and low-altitude sand hazard sections, respectively, to understand the sand hazard law of different-altitude railway sections. Results show the sand hazards at Honglianghe River section mainly occurred in winter and spring and Danghe River section mainly occurred in summer and autumn. The mean grain size of the sandy materials at Honglianghe River section is larger than that at Danghe River section, causing the speed of the sand-moving wind to increase and the frequency of the sand-moving wind to decrease. Under the condition of the decrease in the average wind speed, the sand DP, RDP, Q, and RQ and the measured sand transport quantity decreased. Therefore, the dynamic wind of sand hazards at Honglianghe River section weakened and the overall hazards alleviated compared with that at Danghe River section. The results can provide the bases for controlling sand hazards at different-altitude railway sections.