| Drifting snow refers to various types of disasters caused by snow accumulation,coverage,or flying due to the interaction of factors such as snow and strong winds during the cold season.Due to the complexity of the geographical environment and the large amount of winter snowfall,drifting snow is a common natural disaster near the traffic lines in the mountains.Research has found that road cuttings are one of the most severe forms of subgrade for drifting snow.Therefore,in recent years,with the continuous development of China’s transportation routes,researches on the formation mechanism,spatial and temporal distribution characteristics,prediction,and prevention measures of drifting snow are of great practical significance.This article focuses on the study of drifting snow disasters in road cuttings.A combined approach of numerical simulation and field measurement was used,and the Mixture model in Fluent was utilized to simulate the two-phase flow.The evolution process of wind and snow distribution in road cuttings was investigated,and a comparative analysis was conducted on the drifting snow disaster characteristics of different types of road cuttings.This research provides useful references for the prevention and control of drifting snow disasters.The main research contents are as follows:(1)Classification of drifting snow disaster in cutting.By analyzing the evolution characteristics of drifting snow disasters in cutting with different forms,it was found that cutting can be divided into two categories.The first type of cutting has a vortex inside,and snow accumulates first on the side slopes of the cutting and then gradually advances towards the road surface,ultimately submerging the entire cutting in snow.The second type of cutting does not have a vortex,and snow mainly accumulates at the foot of the slopes on both sides of the cutting before transferring to the road surface.It reaches a stable equilibrium state relatively quickly,and the final amount of snow on the road surface is significantly smaller than that of the first type.The study also found that the critical values for classifying the two types of cuttings are between a slope ratio of 1:1.5 to 1.2.(2)Study on the formation mechanism of drifting snow disasters in road cuttings.For the first type of road cutting with severe drifting snow disasters,this study analyzed the evolution process of the distribution of wind and snow and found that the formation of drifting snow disasters in road cuttings is caused by the increase in snow accumulation on both sides of the cutting,which compresses the scale of the vortex on the road surface and weakens the backflow acceleration effect of the vortex,ultimately resulting in the cutting being submerged by snow.For the second type of road cutting,it was observed that the snow generated at the foot of both sides of the cutting filled the weak wind area on both sides,prompting the snow inside the cutting to reach a stable state.(3)Study on prevention and cross-section parameter selection of drifting snow disaster in cutting.This study focuses on the snow evolution process in the first type of cutting where the disaster is more severe.The initial slow growth of snow on the road surface is referred to as the safety reserve period,and a calculation method for the safety reserve period and the critical snow storage capacity of the upwind side slope is provided.Regarding the selection of section parameters for cutting in drifting snow areas,the study found that an increase in the depth of cutting can effectively prevent snow particles from depositing on the road surface and increase the snow storage capacity of the two side slopes.Therefore,it is recommended that the depth of road cuts in drifting snow sections should be set at 6 meters or deeper. |
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