The Research Of Curved Slope Road Design Theory Based On Vehicle-road Coupling Safety Model

There is undersirable linear in mountain road becasuse of terrain,technical and economic factors and it is an indisputable fact that curved section segement with slope named as “the devil section” with its high accident rate.Linear design specifications used in our country is based on the design speed,it is a constant value.but operation of vehicles speed and design speed may be inconsistent in mountainous area road.And road alignment design less consider vehicle characteristics And there are only principled regulations for vertical and horizontal combination design in specification.It is difficult to quantify definition depiction such as “the small radius of circular curve cann't be inserted at the bottom of the long downhill shall.So the purpose of this article is quantitative analysis design parameters in bending slope of the mountain road section,considering the vechile-road coupling effect,traffic characteristics and security,and provides the reference of quantitative indicators for bending slope section design.Based on the mountains secondary highway as the research object,analyzes the vehicle mechanical properties in curves,slope,bending slope sections and acquire instable critical conditions about the longitudinal overthrow,slip,brake failure and lateral overturning of vechile.Then establish slope length model and radius model in different curved—slope section combined with vehicle traffic characteristics,and acquire design parameter values of curved slope sections under different limit conditions based on the standard values,after derived calculation method of design indicators.afterwards simulate vehicle parameters under different speed,superelevation and slope by the simulation platform,results verify the rationality of the model.the result show that:(1)on curved-slope section,slope and speed of vehicle has a greater influence on the longitudinal stability,and slope length decreases with increasing speed or slope(2)on slope-curved section,the vehicle trajectory are more stable with smaller slope or higher superelevation,radius valves has a positive correlation with speed and superelevation,and longitudinal slope of the first line shape units has little effects to radius valves on second units,(3)on the bending slope sections,the more risky of the vehicle lateral buckling along wih the higher speed or superelevation,and instability state no obvious correlation with longitudinal slope,radius valves also related to the combination methods of synthesis slope,except as superelevation,speed increases.Last provide security technology and measures to the bending slope sections.The research results provides theoretical basis to optimize the line quality of curved slope sections on the mountainous area and has reference value to reduce traffic accidents,and improve the level of safety on mountain section combination slope and curved implications.