Analysis Of The Impact Of Traffic Volume On Dark Ice At The Tunnel Entrance In Cold Regions

At the end of 2020,the mileage of highway tunnels in China has reached 4.69 million kilometers.In some parts of China,the winter climate is cold and there is a large amount of snowfall.When the water content of the road surface is high,invisible ice is generally generated,and the phenomenon of ice formation at the tunnel entrance in cold regions is particularly severe.Invisible ice is an ice layer formed by snowfall or accumulated water freezing on the surface of the road surface during cold weather.This invisible ice layer completely covers the texture structure of the road surface,transforming the contact between vehicles and the road surface into the contact between vehicles and invisible ice.In this case,in order to ensure that vehicles can safely pass through the tunnel entrance section and quickly melt the invisible ice,this article conducted an analysis of the impact of traffic volume on the invisible ice at the tunnel entrance section in cold regions.The first chapter of this article first introduces the research on the disposal methods of invisible ice at the tunnel entrance section in cold regions at home and abroad,clarifies the basic ideas for solving invisible ice at the tunnel entrance section,and explains the purpose and significance of conducting this study.Chapter2 briefly describes the causes and characteristics of invisible ice in tunnel entrance sections,specifically exploring the formation environment of invisible ice and its harm to traffic safety.Chapter 3 establishes a vehicle invisible ice dynamic force model based on mathematical theory,and calculates the melting thickness and corresponding friction coefficient of the invisible ice when a single vehicle passes through the invisible ice road surface,using the vehicle’s driving speed as an indicator;In Chapter 4,based on the calculation results of the previous chapter,a mathematical relationship between the traffic volume at the tunnel entrance section and invisible ice is derived,and a theoretical analysis of vehicle traffic volume,speed,and density is introduced;Chapter 5 investigates the actual traffic volume and vehicle speed at the tunnel entrance section,and incorporates the actual survey data into the derived mathematical model to further analyze the impact of traffic volume on invisible ice at the tunnel entrance section;Chapter 6 summarizes the entire text,proposes innovative points,and provides future prospects.From the above research,it can be concluded that:(1)When a vehicle passes through a invisible ice surface,the driving speed of the vehicle is positively proportional to the melting thickness of the invisible ice,but the driving speed of the vehicle is inversely proportional to the friction coefficient between the vehicle and the invisible ice.When the vehicle reaches a speed of40km/h,the melting of invisible ice rapidly increases and the coefficient of friction decreases rapidly;The degree of invisible ice melting is also closely related to the ambient temperature of the day.The lower the ambient temperature,the slower the melting thickness of invisible ice,and the greater the friction coefficient between vehicles and invisible ice.(2)The thickness of invisible ice melting is significantly correlated with traffic volume.As traffic volume continues to increase,the thickness of ice film melting continues to increase under the continuous action of rubber tires.Especially when the traffic volume reaches 4000 vehicles,the speed of invisible ice melting rapidly accelerates;It can be seen that with the frictional heat generation effect of vehicle tires,the melting speed of the invisible ice layer first slowly increases and then rapidly accelerates.(3)In environments prone to the occurrence of invisible ice,due to the time lag between the occurrence and elimination of invisible ice,in order to ensure the safe driving of vehicles at the tunnel entrance section,on the one hand,deceleration reminders are set up ahead or relevant departments are suggested to take photos of speeding vehicles and impose penalties.On the other hand,staff are organized to lay sand on the invisible ice road surface to increase the friction coefficient between vehicles and invisible ice,accelerating the speed of invisible ice melting,Ensure the safe driving of the vehicle.