Research On Traffic Safety Guarantee Degree For Urban Road Tunnel

With the continuous growth of China's economy,the urbanization rate is getting higher and higher,and the future urban development tends to the exploitation of underground space.Urban road tunnels are widely used in urban construction because they can effectively alleviate traffic pressure and avoid the restrictions of urban traffic crossing mountains and crossing rivers.However,if a traffic accident occurs inside the tunnel,evacuation and rescue are relatively difficult because the tunnel structure is a closed environment.Therefore,it is very important to carry out research on traffic safety of urban road tunnels.This paper has carried out research on urban road tunnel traffic safety based on sub-topic 3 “Risk Assessment Technology of Urban Road Tunnels in Complex Environment” of the third project of the national key research and development plan project “Research on Key Technologies of Operation and Maintenance Safety of Typical Transportation Infrastructure in Cities”.And the main research contents and results are listed below.The first part: on the basis of expounding the concept of urban road tunnel,the different characteristics are compared between urban road tunnels and urban roads,highway tunnels in roads,traffic and environment;characteristics of traffic accidents in domestic urban road tunnels are analyzed,such as time distribution,spatial distribution,accident form,accident vehicle type,accident tunnels,etc;the differences in traffic accidents are summarized between urban road tunnels and highway tunnels;Measures are proposed to prevent urban road tunnel traffic accidents.The second part: the degree to which objective conditions such as roads,facilities,environment,management,etc.provide protection for tunnel traffic safety is defined as “traffic safety guarantee degree”;according to the effect of traffic safety guarantee degree on driving safety,the mechanism model of urban road tunnel traffic safety guarantee degree is established;the influencing factors of urban road tunnel traffic safety guarantee degree are analyzed from the aspects of road conditions,safety facilities,environmental characteristics and management level.The third part: reference and improvement methods are used to evaluate the traffic safety guarantee degree of urban road tunnel;the evaluation indicator system is established based on the analysis of influencing factors and expert opinions;the criteria for evaluating the indicator level are determined with reference to relevant specifications and research results;the method of calculating the weight of the evaluation index is proposed through questionnaire survey and variable weight theory calculation;the classification criteria are given for the evaluation of traffic safety guarantee degree of urban road tunnels.The fourth part: the model is used to analyze the instance tunnel,and the evaluation results are in line with the actual operation of the tunnel,and improvement measures are proposed for the existing defects;the tunnel traffic safety impact survey shows that some factors have a great impact on tunnel traffic safety,such as the horizontallongitudinal alignment consistency of the inside and outside of the portal,emergency parking zone,lighting environment,communication and fire protection system,emergency response plan and drills,etc.Taking urban road tunnel as the research object,this paper analyzes the relevant characteristics of urban road tunnel,defines the connotation of traffic safety degree,and establishes the evaluation model of traffic safety guarantee degree of urban road tunnel.The research results provide a reference for improving the traffic safety of urban road tunnels.It is of great significance for the improvement of the theoretical research system of urban road tunnel traffic safety and the implementation of traffic safety protection projects of urban road tunnel.