Research On The Reconstruction/Extension Projects Of The National Road 214 In Qinghai Province

Compared with the national other provinces and regions, the development of arterial highway in Qinghai province is still at a low level and can not meet the needs of social and economic development and improvement of people’s living standards.The "Five Year Plan" Qinghai Province pointed out that it’s necessary to improve the highway grade and construct the "six vertical", "nine horizontal" and "twenty joint". The 214 National Highway in Qinghai province is the planning of highway network "3410" north south line in vertical, is connected to the trunk roads of Qinghai, Tibet, Yunnan and Sichuan, it plays a very important role to strengthen the capacity of Qinghai province western travel. Because of the influence of permafrost along the thawing settlement, frost heaving, adverse hydrology geology and heavy vehicles, a series of pavement problem, such as cracking, longitudinal cracks appeared, roadbed and road surface subsidence, slope slide, collapse of bridge and culvert settlement deformation and so on the many kinds of diseases, had been appeared on 214 national highway pavement. Therefore, it has important significance to study the extension construction projects on the national highway 214 in Qinghai province of the high grade highway.In order to provide a useful reference for the traffic volume forecast for the future 214 State Road extension, this article first selected the national highway 214 in Qinghai province from Gonghe to the Jiegu highway as the research object, the paper expounds the highway geographic location, climate, hydrological and geological conditions, the comprehensive analysis of the 214 national road through the area (Hainan, Guoluo, and Yushu) of the social economic development and environmental protection situation. Then, a traffic volume forecast was done on the 214 national highway of high grade highway, it suggested that a future years (2030～2034) the traffic will reach four lane highway adaptation range and a comprehensive analysis of the existing highway adaptability was conducted. Then, this paper took a survey of the existing 214 national highway condition, it found that the existing highway disease has seriously affected the normal operation of highway and its service quality was in a very low condition, thus, it needs to treat the pavement disease Immediately. Finally, an extension and construction plan was put forward from different angles, such as the design speed, route, subgrade and pavement, bridge and culvert, closed and auxiliary road, environmental protection and so on.