Wind Dynamic Environment and Wind Tunnel Simulation Experiment of Bridge Sand Damage in Xierong Section of Lhasa–Linzhi Railway

Abstract

The Lhasa–Linzhi Railway is located in the sandy area of the South Tibet valley, with high elevation and cold temperature. The Xierong section is a bridge section where blown sand hazards are severe. However, the disaster-causing mechanism of blown sand hazards in this section is currently unclear, thereby hindering targeted sand prevention and control. To address this problem, the wind dynamic environment of and causes of sand damage in this section are investigated through the field observation of the locale and a wind tunnel simulation experiment. Results show that the dominant sand-moving wind direction in the Xierong section is SSE. The wind speed, frequency of sand-moving wind, sand drift potential (DP), and maximum possible sand transport quantity (Q) in this section are relatively high during spring (March to May) and low during other seasons. The yearly resultant sand transport direction (RDD, RA) is SW. The angle between the route trend of this section and the sand transportation direction is 30°–45°, and the sand source is located in the east side of the railway. During spring, sand materials are blown up by the wind, forming blown sand flow and movement from the NE to SW direction. Increased wind speed area is formed between the top of the slope shoulder of the windward side of the bridge and the downwind direction of 3H, causing blown sand erosion. Meanwhile, weakened wind speed areas are formed within the distance of -3H at the upwind direction and from the downwind direction of the 3H to 20H of the bridge. These areas accumulate sand materials at the upwind and downwind directions of the bridge, thereby resulting in blown sand hazards. This research provides a scientific basis for the prevention and control of sand damage in the locale.

Dynamic mechanism of blown sand hazard formation at the Jieqiong section of the Lhasa–Shigatse railway

“…The wind-sand flow transport is blocked by the emergence of the railway roadbed, thereby causing sand materials to accumulate near the railway and cause disasters. Referring to the wind tunnel experimental settings in the literature (Xie et al 2020), the authors conducted a comparative experiment on the sand transport rate with and without the railway roadbed models. According to the measurement results of the wind tunnel experiment (Figure 8), the sand transport rates measured under the five experimental wind speeds (6,9,12,15 and 18 m s À1 ) without the railway roadbed are 5.…”

Wind-Tunnel Studies on Sand Sedimentation Around Wind-Break Walls of Lanxin High-Speed Railway II and Its Prevention

“…Although there are many similarity requirements in wind-tunnel experiments, such as geometric, motion, dynamic, and thermodynamic similarity [22,23], with sand flow it is difficult to perfectly simulate the shrinkage ratio of the model size, boundary layer size, and particle size in the real environment. Therefore, in this study, some compromises must be adopted [24].…”

“…Therefore, in this study, some compromises must be adopted [24]. Only the geometric similarity of the model, the motion similarity and dynamic similarity of the wind field, and the corresponding wind-tunnel results were mainly used in the mechanical studies as a key problem to be solved in current wind-sand physics [23,25,26].…”

Maintenance Time of Permeable Asphalt Pavement Based on Entropy–Analytic Hierarchy Process Analysis

“…The maximum possible sand transport quantity, resultant quantity, and resultant angle of the maximum possible sand transport were calculated as follows [37]:…”