The Research In Effect Of Protection By Preventing Windstorms And Fasten Sand Measures In Ji-Er Railway Desert Regions

The railway has been more and more liked by the public for its speed, safety, comfort and environmental suitability. And recently the nation has throw lots of manpower and material resources on its construction, to make the inter-provincial railway transport more "bus-like". Driven by the fast development of railway construction, the railway line has extended to mountainous area and the dessert edge, making it more necessary to study the railway, and as an important part of railway in dessert, the measures about wind prevention and sand fixation deserve more research.The paper is based on the Ji-Er railway project (the railway which connect the Jinin and Erlianhaote), and has used the Fluent software combined with lots of field experiment to do a systematic research on the measures about wind prevention and sand fixation in dessert. The main research results are:(1) Measure the surface roughness height of the protective measures on both sides of the railway line and compare it with the upwind unprotected area, the result reveals that the protective measures has a positive effect on the nature of the underlying surface, among which the elm area process the largest roughness height, followed by the Caragana forest, and the nylon mesh sand barrier rank last;(2) By comparing the wind profile distribution of the unprotected and protected area, we find that in windy weather, the protection measures has strong airflow disturbance. Among the three protection measures, the elm is strongest, followed by Caragana forest, nylon mesh sand barrier is the weakest;(3) By the experiment on wind speed, using the contrast research method, we has studied the protection effect of various measures. The result reveal that the elm has obvious effect on weakening wind speed within3m height, and the Caragana forest and nylon mesh sand barrier has mainly reduced wind speed within2m height;(4) By the sand-collecting experiment, using comparative study method, we studied the sand-fixing effect of protective measures, and found a set of protective measures has changed the flow characteristics of the sand structure, and with the development of protection system, the amount of sediment has significantly reduced;(5) By doing numerical simulation using the Fluent and analyzing the protective effect that the protective measures has in extreme weather, we provide a theoretical basis for the actual project.