Research On Technical Index And Security Measures Of Trunk Road In Mountainous Areas

The road is set back curve when routes are the terrain elevation limit line can not rely on natural exhibition line extension of a plane linear distance form overcome the elevation difference or use of natural exhibition line taken will pay the economic,safety and environment is costly,and is widely used in the linear design of the low speed of highway.With the social and economic development,the trunk highway extends to the mountain depth,and the design concept is also progressing.When the route along the terrain to overcome the elevation difference between the control points,due to the economic setting back curve is better than the helix line development and more efficient use of terrain potential,began to receive the attention of the designers.However,the curve setting curve of mountain arterial highway is still in the exploratory stage,and how to set up the curve curve,master the technical indexes and ensure the safety of traffic in the mountainous main highway still needs to be studied deeply.This paper from the plane alignment,design speed,plane curve angle and other factors,on the mountain road back curve is defined,and summarized its form and shape;from the set back curve of topography,ensure traffic safety,engineering economy,environmental protection and traffic capacity and other aspects of the factors affecting the main highway in mountain area set the back curve.Linear composition and vehicle lateral force stability back curve based on the main and auxiliary curve are considered separately,the minimum radius of circular curve is given;based on the dynamic performance of large car maximum longitudinal slope of the back curve;through the research section of the standard curve back cross section combination form,combined with the characteristics and the characteristic curve of car back the proposed road widening of the back curve and the maximum value of super high rate;requirements for distance back curve sections is given;by defining the back curve between the transition section of the adjacent,and the driver driving operation in this section are analyzed,the curve between adjacent back transition section length.The back curve road model is built by the Trucksim software,select the driving speed,lateral acceleration,driving trajectory,tire vertical force and steering wheel angle angular velocity(peak)and other indicators,safety indicators on the mountain curves back trunk road is verified.Referring to the research achievements about the rural highway security measures at home and abroad,combined with linear characteristics and setting method of the back curve,from the set speed limit signs,shoulder rumble strips,chevron,strengthen the guardrail,traffic signs,emergency lane,enhance road friction coefficient and put forward the measures to ensure the safety of the back curve.