Characteristics of alpine Gobi surfaces, blown sand transport regularities, and prevention measures along the Liuyuan Golmud Expressway

The Liuyuan-Golmud Expressway is located in an inland hyper-arid region, where the dominant environmental feature along the route is the Gobi aeolian sand environment. Current understanding of the Gobi surface characteristics, wind dynamic environment, and sand transport regularities along the route remains limited. This has hindered the development of targeted blown sand prevention and control measures and has resulted in severe blown sand hazards on the expressway. Based on Gobi field investigation, sampling, and analysis, the surface sediments of the Gobi along the Liuyuan-Golmud Expressway showed a moderate particle-size distribution, ranging from silt (8 ~ 4Φ) to boulders ( < - 8Φ). Their mass composition was dominated by fine sand (3 ~ 2Φ), fine gravel (- 1 ~ - 2Φ), and medium gravel (- 2 ~ - 6Φ), with an average gravel coverage of 70.42%. Wind and sand observations and calculations showed that the sand-moving winds along the Liuyuan-Golmud Expressway were mainly NNW, WNW, and W. The average wind speed, sand-moving wind frequency, sand drift potential (DP), resultant drift potential (RDP), maximum possible sand transport quantity (Q), and resultant maximum possible sand transport quantity (RQ) were higher in spring and summer and lower in autumn and winter. The resultant sand transport directions were mainly E, ESE, SE, and SSE. In the Da Qaidam, Fushaliang, and Golmud sections, the angles between the blown sand transport direction and the road alignment were relatively large (60.9 ~ 75.0°), and blown sand hazards were severe. Targeted prevention and control measures should therefore be adopted for these sections. Spring and summer are the key periods for blown sand prevention and control, and the western side of the expressway is the main area requiring protection. These results provide a reference for the prevention and control of blown sand hazards on expressways.