Study On The Appropriate Technical Standard Of First-class Highways Upgrading And Rebuilding In The Plain

In order to ensure first-class highways upgrading and rebuilding projects in the plain to be smoothly implemented, the paper is a study on how to choose appropriate technical standard for first-class highways upgrading and rebuilding projects in the plain. Firstly, based on the investigation on mainline first-class highways of provincial passage of Inner Mongolia Municipality which is the most representative first-class highways of all first-class highways in the plain, the characteristics of first-class highways in the plain are summed up. Next, from controlling factors of highway design, upgrading and rebuilding methods are divided into four methods including no speed-up and widening but only closing,speed-up and closing but no widening,no speed-up but widening and closing,speed-up and widening and closing. And a process is put up on how to choose appropriate method of first road upgrading and rebuilding, which include alignment index analysis,alignment index adaptable evaluation in order to obtain appropriate design spend,traffic capacity analysis and service level evaluation. Alignment index adaptable evaluation is an evaluation method of adaptability between exiting highway alignment and design speed by applying the theory of fuzzy comprehensive appraisal, as increased speed or not increased speed transformation basis. Then, through analysis and evaluations of technical index of mainline first-class highways of provincial passage, it is suggested that no speed-up and no widening and only closing is the most appropriate upgrading and rebuilding method for provincial passage. Finally, because mainline first-class highways of provincial passage is the most representative in the plain, first-class highways upgrading and rebuilding projects in the plain must adopt no speed-up and no widening and only closing, which must retain existing roads as far as possible and maintain existing vertical and horizontal-technical index as far as possible. And suggestions on choosing first-class highways upgrading and rebuilding technical standard in the plain is put up, including upgrading and rebuilding methods,design speed,subgrade,pavement,primary technical index and so on.