A Study On Snow Drift And Subgrade Protection Measures In Zhanghu Railway

The Drifting Snow Disaster is a common natural calamity in northern China.It buries roads and railways,and causes great disasters for winter transportation.Zhangjiakou-Hohhot Passenger Railway passes through a variety of geomorphic units,and accidents involving blizzard-buried railways have occurred in the area,which is a region with more serious Drifting Snow Disasters.Based on the characteristics of the project,this thesis collects data such as snow particles,wind speed and wind direction on the spot,and the numerical simulation software of fluid mechanics is used as the platform to carry out numerical simulation of embankments of different heights,different depths of roads,different wind directions and shallow half-decks and other subgrades and wind speed fields of snow prevention projects.Through the analysis and study found out the snow accumulation law of the railway subgrades,that is,whether it is on the windward side or the leeward side,there will be different degrees of snow accumulation in the halfway,shallow road and deep road,especially the long large wide slow deep roads on the windward side.Combines with the study of factors such as topography,snowfall,wind direction,this thesis also analyses and screens out the snowdrift disaster prone sections in Zhangjiakou-Hohhot railway,and set as the focus of snow prevention and control.In this thesis,the wind field near the snow-shielding wall is numerically simulated,and the law of snow accumulation near the snow-shielding wall is analyzed.Design optimization suggestions are made for the height of the snow-shielding wall,the spatial arrangement,and the arrangement of the combined snow-shielding wall.The numerical simulation of the wind field near the snow-proof fence is carried out,and the design optimization suggestions for the air-proof rate,height and space arrangement of the snow-proof fence are made.Furthermore,numerical simulations are also carried out on the wind farms with different combinations of railway protective fences and snow-shielding wall or snow-proof fence.It is believed that the installation of railway protective fences outside the snow-shielding walls can increasethe amount of snow blocking on the wind side of the snow-shielding wall.However,when the railway protective fence is 1-3 meters away from the embankment or the roadside slope,the prevention and control of Drifting Snow Disaster is negative.This thesis puts forward reasonable suggestions for the layout of the railway protective fence.Through the return visit investigation on the effect of on-site snow prevention measures,the reliability and correctness of the research conclusions are verified.In addition,combined with the actual situation the site,three new designs of snow-proof fences,respectively the movable plate snow-proof fence,the ventilation movable plate type snow protection device,and the snow-proof fence based on I-type column and reinforced concrete ventilation board,are proposed,and finally achieve the advanced purpose of engineering economy,simple construction,reduced land occupation and good effect.