Optimization Of Wind-blow Snow Prevention Technology For Ordinary Highway In Northern Hebei Province

China’s vast territory,geographical and climatic conditions are complex,highway wind and snow disaster caused traffic jams,seriously affect the normal operation of highway and vehicle safety.In this thesis,according to the climate characteristics of northern Hebei region,fluid simulation software Fluent was used to conduct numerical simulation to study the influence of the layout of snow retaining wall and the height of highway subgrade on the wind speed flow field of road surface.According to the numerical simulation results,the setting parameters of snow retaining wall were determined and model experiments were conducted.The results of numerical simulation and model experiment are verified to prove the reliability of design parameters and provide reference for practical engineering.According to the experimental results,the conclusions are as follows:(1)Fluent software is used to simulate the distribution characteristics of flow field around embankment and whole cutting.The results show that the wind speed curve near the embankment presents a "M" shape distribution,and the wind speed weakening zone is formed on the windward slope of the embankment,and the turbulent zone is formed on the leeward slope.The wind speed near the whole cutting presents a "U" shape distribution,and there will be negative wind speed inside the cutting,resulting in backflow and vortex flow.(2)Design and optimize the subgrade height.The flow field changes under different roadbed heights were analyzed by numerical simulation.When the roadbed slope was 1:1.5,the optimal design height of embankment was 2m～4m,and the whole cutting depth was 4m～8m.(3)The influence of snow retaining wall on the flow field of roadbed was numerically simulated by Fluent.The results show that: When the wind and snow flow is close to the snow retaining wall,the velocity of the airflow blocked by the wall decreases rapidly,and the airflow near the ground is stratified.The vertical velocity distribution contour of the airflow on the leeward side of the snow retaining wall presents an "S" shape distribution,while the wind speed at the same horizontal position but at different heights presents a "U" shape distribution.When the height of the snow retaining wall is 1.5m,the best effect is achieved when the distance between the wall and the embankment is 13.33 to 16.67 times of the wall height.The distance between the whole road cutting and the snow retaining wall should be 13.33 times higher than the wall height,and the distance between the snow retaining wall should be 16.67 times higher than the wall height in the section where the wind-blown snow disaster is more serious.(4)The model experiment results show that the wind speed variation of embankment and whole cutting is basically consistent with the numerical simulation results.In the form of embankment,when the spacing between snow retaining wall and roadbed is 0.8～1.0m(13.33～16.67 times wall height),wheat bran deposition at the two slope feet can be effectively reduced.In the whole road cutting form,wheat bran deposition is the largest when the distance of snow retaining wall is set at 1.0m,which increases by 25% compared with that at 0.4m.