Research On The Security System Of Downhill Section Of Expressway

With the steady implementation of the National Poverty Alleviation Policy,there are more and more mountainous expressways in the western region of China.It is expected that by 2020,the national expressway main line in the impoverished areas will basically reach a breakthrough.At the same time,with the rapid development of domestic macro-economy,the proportion of heavy-duty vehicle transportation in China’s highway traffic is increasing,and high-risk sections with heavy downhill slopes and heavy-duty vehicles constitute the main influencing factors for the frequent occurrence of highway accidents in the mountainous areas in the western region.Therefore,it is necessary to carry out research on the problems existing in the installation of traffic safety facilities on dangerous downhill sections of mountain roads at present,and to develop a comprehensive and guiding method for setting safety facilities to further reduce the incidence of traffic accidents on such road sections.This paper analyzes and studies the traffic safety problems in the long and downhill sections of expressways:(1)In this paper,based on the analysis of domestic and foreign research status,technical method features,and design of safe-rising lanes for the installation of safety facilities on dangerous downhill roads in mountainous areas,a slide-type mesh cable interception device was designed and applied to safe-rising lanes.In the simulation calculation process,the application results show that the slide-type network interception device has a flexible design and reasonable structure,and can meet the design requirements of the safe-fence lane.(2)The similarities and differences of the technical standards for safety management of downhill roads in mountainous areas at home and abroad were compared.Ten roads belonging to consecutive large downhill slopes and frequent traffic accidents were rectified.Mathematical analysis methods were used to discuss the failure of heavy-duty vehicles and the horizontal lines of vehicles.The problem of unbalanced stability,lack of sight distance between drivers and poor road conditions,etc.,gives a detailed mathematical analysis derivation process.The relationship between driver’s driving characteristics,road alignment conditions,vehicle driving characteristics and traffic environment was studied.From the two aspects of active protection and passive protection,a technical route for setting up safe facilities for highways with long downhill sections was proposed.The method of setting up a complete security system was analyzed,and a complete mathematical modeling and computer simulation was performed using a heavy-duty vehicle deceleration ridge as an example.(3)This paper analyzes the necessity of setting up safe-avoidance lanes on the downhill section of mountain roads,and presents the method for selecting the safe-rising lanes,and completes the design of the safe-rising lane structure.The specific contents include the approach lanes for safe-rising lanes and the braking slope beds for safe-rising lanes.The safety lane protection device was used,and the finite element analysis of the safe-avoidance lane was performed using the LS-DYNA program.The process of finite element analysis using the LS-DYNA program was explained,and the analysis results were given.A chute-type mesh cable intercepting device was designed.The design includes the simulation of chute-type damper,the structure design of chute-type mesh cable interception device,and the selection calculation of the installation position of slide-type mesh cable interception device.Road network cable interceptor device has been promoted.