Numerical Simulation of Sand Deposition around Windbreak Walls along Both Sides of High-speed Railway Subgrade in Strong Wind Area
The Lanzhou-Xinjiang high-speed railway traverses multiple strong wind areas,causing a serious impact on its safe operation.In order to reduce the harm of strong winds to the railway line,a large number of windproof structures have been built in the strong wind areas,with subgrade windbreak walls the most common.Despite the reduction of the impact of wind damage,windbreak walls cause serious line sand accumulation problems.In this paper,the characteris-tics of the flow field around the windbreak walls on both sides of the subgrade under different wind speeds were studied through numerical simulation.The ratio of wall shear stress generated by wind to sand shear stress was used to determine the type of surface sand deposition and erosion.It is found that a clockwise vortex and a counterclockwise vortex are formed between the two rows of wind barriers,with a clockwise large vortex formed on the leeward side of the second row of wind barriers.With the increase of incoming wind speed,the size and intensity of the vortex both increasing.The ex-istence of eddy current sweeping away some sand particles significantly reduces the sediment of sand particles near the leeward slope of the embankment and on the subgrade surface.When the incoming wind speed is 24 m/s and 30 m/s,reverse erosion of sand particles appears on the subgrade surface of up and down tracks.The results of the comparison of sand accumulation laws between single and bilateral wind barriers show that the installation of bilateral wind barriers sig-nificantly reduces the sand accumulation on the line.This study not only reveals the law of aeolian sand deposition on the subgrade surface around the bilateral windbreak walls of the railway in the windy area,but also has important guiding significance for the protection construction of the railway in the windy area in the future.
万方数据
维普
