Research On Prevention And Cure Techniques Of Snowdrift On Expressways In Cold Areas Of Northern Hebei

China has a vast territory and complex geographical and climatic conditions.Expressway in most areas of northern China are affected by snowdrift.The snowdrift on the expressway caused traffic congestion,which seriously affected the normal operation of the highway and threatened the safety of pedestrians’ lives and property.In this context,based on the Zhangbei-Shangyi Expressway project,in accordance with the climate characteristics of northern Hebei,relevant research on the prevention and control of snowdrift will be carried out.Using Fluent as a means to study the influence of road ancillary facilities,roadbed forms and parameters on the road wind flow field.On this basis,the setting parameters of the snow wall are determined,and model experiments are carried out with wheat bran as a substitute for snow.The research provides technical reference.Numerical simulation and model test results are mutually verified to prove the reliability of the test results,and provide technical reference for the research on the cause of snowdrift and prevention technology.The main conclusions :(1)It is determined that the road with three-wave guard fences has the best effect in preventing snowdrift,and the concrete guard fence with a height of 1m has the worst effect.Through Fluent numerical simulation,analyze the pavement flow field distribution with four different protective fences.The low wind speed area of the pavement with three-wave protective fence is the smallest,the low wind speed of the pavement behind the concrete fence with a height of 1m The area is the largest,and snowdrift are more serious in actual projects.(2)The area of the road surface with low wind speed increases with the increase of the slope and the height of the roadbed.With the increase of the slope of the side slope and the height of the roadbed,the area of the low wind speed area of the leeward half cut and the road surface of the whole cut has increased significantly.In the embankment and the windward half-cut,the law is similar to the leeward half-cut.Although the width of the low wind speed zone no longer increases after the height of the subgrade increases to 8m,its height increases significantly.Therefore,the total area of the low wind speed zone has also increased overall.(3)The relationship between the setting distance of the snow wall and the height of the snow wall is determined.From the numerical simulation results,it can be seen that the relationship between the setting distance L and the wall height H:half-windward cutting road,single wall: L=30H;double wall: L=26H+29H.Embankment,single wall: L=36H;double wall: L=26H+41H.Half-cut leeward road,single wall: L=18H;double wall: L=25H+16H;whole road cutting,single wall:L=16H;double wall: L=26H+14H.(4)The entire road cut is the most severe form of snow-covered roadbed,followed by the leeward half cut,and the embankment is the lightest.The greater the height of the snow wall,the better the protection effect.The protective effect of the double-channel snow wall is more obvious than that of the single-channel snow wall.The 1.2m+1.2m snow wall combination has the best protection effect.The wheat bran accumulation on the road surface is reduced by an average of 50%,and the maximum can be reduced by 74%.