Highway Subgrade And Roadside Design For Preventing Against Blowing Snow Hazards

The snowdrift is one of natural disasters which often occur on highways in the north of China in the winter; it can cause the snow accumulation on highways which disturbs the traffic flow and reduce the visibility.Snow drift area in China mainly distribute in the stable snow cover region whose latitude and elevation is high and the hypsography change is always big, namely the east of Qinghai-Tibet Plain and all around edge mountainous area, the west of Xinjiang Altai and the west and the north of Tianshan, the mountainous area in the northeast and inner Mongolian.These area with cold winter and strong wind, the snowfall is also big. It's hard to adjust measures to local conditions because of the laggard prevention technique, so the road is still blocked by the snow although being set up the snow pretection measure.Diffferent extent road snow disaster have happened every year although the highway administration and the maintenance department must invest several million even more than ten million yuan every year to remove snow guarantee the smooth funds, the snow block is still unavoidable.Not only the snow drift disaster creates seriously affects to people's normal life and the industry and agriculture production, but also have difficulties in rescues.The snow drift snow disaster already was the long-term puzzle to highway construction and transportation in the western area.This paper depends on the Construction Technology Projects of the Transportation of Western China, thorough research the rational highway selecting line in the snow drift disaster area, the effectual roadbed design of the Section and the roadside facilities&structure design.The paper first selaborated the research background, the goal and the significance through analyze the spatial distribution characteristic in snow drift of china and the influence of the snow drift to the transportation construction and the economy development. Summarize the technique research , Standard Establishment and the practical application related to the viewing of road snow drift disaster protection about roadbed and roadside design from domestic. In this foundation, has determined the main research content and the frame.In the second chapter, the paper systemically analyzed the occurrence mechanism of the snowdrift and the reason and influencing factors of the occurrence of the snow accumulation on highways, especially in the condition of various typical transects of roadbeds ,further, put forward the radical principle of prevention and cure, including controlling the supply of snow, altering the direction of the wind, augmenting the wind speed on the road surface, altering the configuration of the flow structures, keeping from disturbing the airflow. In order to carry out each kind of design preventing and controlling research to lay the rationale.In the third and the fourth chapter, separately has carried out the design preventing and controlling engineering research from the roadbed and the roadside in the snow drift disaster.In the third chapter, the paper summarize 14 principles about road selecting line in the snow drift area according to the investigation and unite the formerly studies and the practice. Analyzed the route selection principle aerviceability using the investigation date and the pratical examples.Afterwards, make the overall principles.Based on the overall principle, the paper research on the embankment and 3 kind of cut section form design, viewing from prevented and reduced snow drift disaster, has given these important principle of design systematically.In the fourth chapter, the paper separately disscus the research on the snow protection design and utilisation of the snowbreak and so on. The author mainly expounded the principle of prevention and cure and method of setup about the wall of blocking snow and snow fence, quantified and standardized the parameters of design by analyzing the factors influencing the effect of preventing snow. The influence factors of the effect of preventing snow which were studied were the height of the wall of blocking snow, the angle between wind direction and the direction of transects of the wall of blocking snow, terrain and the design of the end of the wall of the blocking snow, the wall of blocking snow was classified into two kinds which are the single wall of blocking snow and the double wall of blocking snow and their factors were embodied; The influence factors of the effect of preventing snow of snow fence which were through wind rate and height of it was analyzed to derived the technology of systemically project construction which including the structure of snow fence, through wind rate, height ,number of columns, the space that is from the ground, the distance that is from the roadside, the angle between the wind direction and the transects of snow fence, the design of the end of the snow fence, length.Finally, the paper summarize to the development research. Protection plan of the road snow drift disaster, the Mechanism of visibility disorder, the preventive measures and so on is described.