Research On Operation Accident Characteristics And Fire Risk Assessment Technology Of Small Radius Curve Tunnel In Urban Road

In recent years,my country’s urbanization process has significantly accelerated,and the development of the transportation industry has also accelerated.With the corresponding increase in the number of urban road tunnels,various types of urban road tunnels of different linear types continue to emerge.In order to avoid demolition,overcome the influence of adverse terrain and reduce the damage to the urban landscape,small radius curve tunnels of urban roads came into being.Urban road tunnels play a nonnegligible role in the lives and traffic travel of urban residents,and it also brings a series of safety issues.Because the tunnel is a long and narrow confined space,once a fire accident occurs,the combustion products will generate high temperature and a large number of toxic and harmful gases.These substances will spread quickly in the tunnel,especially the small radius curve tunnel,which is more likely to cause casualties.In order to ensure the safety of urban road traffic and smooth urban traffic,it is necessary to establish a more scientific fire assessment method for the operation of small radius curve tunnels on urban roads.First,this article collected 650 urban road tunnel traffic accidents using python web crawlers.Through the characteristic analysis of the collected accident data,the preliminary rules of the causes,types,spatial distribution,time distribution and tunnel characteristic distribution of urban road tunnel accidents in my country are obtained.The fire accidents of urban roads and tunnels are analyzed in detail,and the influencing factors of fire risk of urban roads and tunnels operation are found.By analyzing the operating characteristics of small radius curve tunnels on urban roads,the determination method of urban road small radius curve tunnels,the linear characteristics of small radius curve tunnels,traffic operation characteristics and fire risk characteristics are obtained.Secondly,the paper briefly introduces the simulation software FDS and Pathfinder,analyzes the behavior of escaped persons in the event of a tunnel fire,collates previous research results,and puts forward the limits of the escaped persons under the triple conditions of temperature,carbon monoxide concentration and visibility.Endure time judgment conditions.Third,based on the previous factors affecting the fire of urban road tunnels,the risk sources of small radius curve tunnels in urban roads are identified,and then the fire probability rating system for urban road tunnel operations is proposed,and the weight of each factor is determined by the AHP method.Then use the simulation software to establish the urban road tunnel fire consequence evaluation rating standards,and then integrate the urban road tunnel fire probability rating and the fire consequence rating to establish a scientific urban road small radius curve tunnel operation fire risk assessment method.Finally,the article takes the Changhe Road Tunnel in Yuzhong District of Chongqing as an example to analyze the fire risk level of the small radius curve tunnel operation and gives the fire risk control measures for the small radius curve tunnel operation of the city.