Study On The Vertical And Horizontal Index Of Highway Interchange Ramp Under Snow And Frozen Conditions

Interchanges are an essential part of the highway component.Due to the vast territory of China,geographical and geological conditions,climatic conditions,and traffic conditions vary from region to region.There are significant differences between North and South.During the interchange design and construction process,according to China’s current highway design specifications,there is no detailed description and in-depth study of the interchange of snow-covered and frozen areas.In designing,the design personnel choose the index to be more arbitrarily,more actual operation is based on experience,which cannot meet the requirement of interpassability road traffic capacity and driving safety of the snow-covered and frozen area Therefore,the research on the vertical and horizontal combination index of the interchange in snow-covered and frozen areas has become an urgent problem to be solved in the interchange fieldStarting with the relevant reports on road freight transport issued by China,we analyze the current status of different types of highway freight trucks in China,and use statistical analysis and chart analysis to analyze the sales volume report of heavy trucks in China’s market in recent years and come up with the leading models of this paper.According to the characteristics of vehicles driving in snow-covered and frozen areas,suitable indicators for the evaluation of handling stability of trucks are selected to determine the specifications involved in snow-covered and frozen areasThere is no exact definition and scope for the snow-covered and frozen areas.The definition of the snow-covered and frozen areas and the scope of the road design are very rough According to the statistics of temperature and precipitation data of the Meteorological Bureau in recent decades,the snow conditions in Xi’an City in January were used to test the friction index of snow and ice conditions.Use a pendulum meter to measure the road friction index at different locations during different snowfall icings.Analyze the friction index under different thickness snow cover,different thickness ice layer,rut,fluffy snowfall or compaction snow Analyze the experimental results to determine the friction index under conditions of snowfall,ice formation and ruttingStarting from the parking distance in snow and frozen conditions,the radius of the minimum circular curve of the tunnel in snow-covered and frozen areas was calculated.A safety-vehicle skid model in snow-covered and frozen areas was proposed,and a safety speed rollover model was combined with stability guarantee to obtain snow and frozen areas.Round curve related parametersBased on the dynamic characteristics of the vehicle,calculate the ideal maximum longitudinal slope and the unlimited maximum longitudinal slope in the snow-covered and frozen areas,and obtain the maximum vertical gradient of the snow-covered and frozen areasThis paper proposes the calculation value of synthetic slope for safe parking of trucks in snow-covered and frozen areas,and the calculation value of synthetic slope for trucks that do not slip on downhill slopes.It is limited by the start of vehicle parking in snow-covered and frozen areas.Use Trucksim simulation software to establish experimental models and loads,set relevant driving parameters,establish a simulation road model,set geometric parameters,and friction indexs.Combining with Matlab programming,comprehensively using regression analysis and numerical analysis to verify the calculated value of synthetic slope in snow-covered and frozen areas,corrected the maximum vertical slope in snow-covered and frozen areas,and confirmed the correctness of the vertical and horizontal indexes of snow-covered and frozen areasThe research results of the thesis have theoretical value and practical significance for perfecting the vertical and horizontal index design of the snow-covered and frozen areas in China.Improving the operational safety of the interchange snow frozen area areas.It provides technical support for the interchange design in snow-covered and frozen areas in China.