Study On Operating Risk Assessment And Fire Evacuation For Road Tunnel

With the characteristic of unpredictability, road tunnel has enormous risk in the construction and operation stage. Recent disasters in road tunnel caused great casualties and economic losses, producing a serious impact to society. Therefore, it is imperative to introduce the risk management theory into road tunnel project. In recent years, some achievements have been gained in risk management study for road tunnel construction in China, but little study has focused in operating risk.In this dissertation, a relatively complete operating risk assessment system has been set up for road tunnel in China. This system includes the operating accidents analysis, operating risk acceptance criteria and operating risk quantitative analysis, fire heat release rate and fire evacuation study etc.Firstly, the dissertation collects 208 traffic accidents and 103 fire hazards in domestic,31 foreign serious fire hazards in abroad for road tunnel operating process. Through analyzing these hazards in road tunnel, some tentative rules have been obtained, for example, hazard forms, hazard causes, accident rate and losses, etc. Then, some basic factors influencing the road tunnel risk have been listed in the dissertation.Secondly, the dissertation studies the major accidents fatality rate (including traffic fatality rate) and the natural disasters fatality rate in China in 2000～2008. Combined the principle of personal risk acceptance criterion, a proposed personal risk acceptance criterion for road traffic system in China has been put forward for the first time. The acceptable standard is 1×10-6 and the tolerable standard is 5×10-5. Subsequently, through analyzing the social risk acceptance criterion in several Europe countries and considering the principle of social risk acceptance criterion and China national conditions, a proposed social risk acceptance criterion F-N curve for road tunnel is posed in China for the first time. Then, the proposed economic risk acceptance criterion F-D curve and the environmental risk acceptance criterion F-T curve are brought forward too.Thirdly, combing the basic model of risk analysis with the characteristics of road tunnel operating, the dissertation sets up a quantitative risk analysis method for road tunnel operating in China. In the road tunnel operating risk assessment model, proposed design accident scenes, probability model and loss model are put forward. And then the probability and consequence of fire and dangerous goods leakage are given.Fourthly, as representative road tunnel accident, a systematic study for fire hazard has been made and the following results have been achieved.1) Pre-flashover design fire model is suggested for fire risk assessment in road tunnel. Then, the design parameters and the growth curve of heat release rate for different design fire are given.2) A basic framework for fire evacuation in road tunnel is preliminary proposed.3) Through comparing and analyzing the toxic of several key gases and high temperature of FED extension model and that of Puser model, the dissertation firstly poses taking Puser asphyxia gas model and modified Crane high temperature gas model as the escape condition for evacuation person in road tunnel fire.Fifthly, taking Yanmenguan road tunnel as example, the dissertation analyzes the social risk in its operating stage. Through analyzing different design accident scenes in Yanmenguan tunnel, the frequency and the consequence of different accidents have been given and the social risk F-N curve have been drawn in this dissertation. So, the practice of the risk assessment method in this dissertation is verified.Finally, the dissertation briefly sums up 27 basic measures for risk reduction in road tunnel operating stage. Several measures to improve the safety for road tunnel operations are put forward according to user, operations management, infrastructure and vehicle.