Research On Safety Evaluation And Improvement Measures Of Mountainous Freeway Bridge-Tunnel Sections

With the rapid development of national economy, especially with the implementation of western development strategy, the mountainous freeway is coming into a rapid expansion. The construction of mountainous freeway provides good travelling condition to vehicles and improves the transportation, which are helpful to the economy of mountain area. However, with the geological terrain restrictions, there are great quantities of bridge-tunnel sections. The traffic accident becomes more and moer serious that brings graveness consequences to human life, wealth and new challenges to traffic safety protection on mountainous freeway. We do not have regularities cognition of traffic safety on mountainous freeway bridge-tunnel sections. Therefore, discussing traffic accidents has important significance to prevent traffic accident and to improve the safety situation of bridge-tunnel sections.Based on the traffic accident data, this paper carries on an in-depth study on traffic safety of mountainous freeway bridge-tunnel sections, including traffic characteristics analysis, accident causes analysis, safety evaluation of bridge-tunnel sections and improvement measures research.First, through the analysis of accidents data, this article studies the accident characteristic by applying the statistic methods, including time distribution, climate distribution, accident form distribution and vehicle type features. The distribution regularities of serious accidents in different forms are obtained.Secondly, this article analyzes influence factors of mountainous freeway bridge-tunnel sections. From drivers' traffic behavior, it analyzes human factors in traffic accidents. From three aspects of road alignment, transport facilities and pavement condition, it analyzes road condition factors in traffic accidents. From three aspects of traffic volume, traffic composition and vehicle speed, it analyzes traffic condition factors in traffic accidents. According to fog, snow, frozen and side wind, it analyzes climate factors in traffic accidents. The main causes of accident are determined by principal component analysis method.According to the accident causes analysis of mountainous freeway bridge-tunnel sections, in order to further identify potential threats and to provide guidance to the next improvement job, this article sets up the mountainous freeway bridge-tunnel sections safety evaluation system based on bayesian network.Finally, with the view of system security, according to the influence factors of mountainous freeway bridge-tunnel sections, this paper puts forward to improvement measures from three aspects of road condition, unfavorable climate environment and traffic management.