Research On Organization Of Highway Tunnel Evacuation Under Fire Environment

With the continuous acceleration of highway development,the scale of new highway tunnels is increasing.Because the highway tunnel has the characteristics of longitudinal length,internal closure and limited ventilation,when a fire occurs,the rapid spread of smoke reduces the visual scope and the perception of distance of pedestrians,and affects the evacuation crowd in the fire environment,at the same time,it causes panic and conformity.Therefore,it is of great significance to study the evacuation of highway tunnel crowd in fire environment and determine the corresponding safeguard measures for improving evacuation efficiency,reducing casualties and ensuring the safety of road participants.From the perspective of psychology and behavior,this thesis establishes the highway tunnel fire scene in virtual scene.The walking speed and AVHR of the testers in the evacuation process were collected through the simulation experiment.The significance of different environmental factors and their interactions on the walking speed and panic factor was studied by using the method of multivariate analysis of variance.The multiple regression model was used to describe the influence of different environmental factors on the walking speed and panic factor.The fitting accuracy of the model reached 83.06%and 86.98%.The value of RSS and MSE is small,indicating that the selection of the model was appropriate.Secondly,based on the traditional floor field model,the fire field strength F_ij and extinction coefficient are introduced to describe the influence of fire on pedestrian escape behavior and visibility.Proposing the evacuation model of highway tunnel under fire environment combined with the influence of highway tunnel fire environment on the speed and panic psychology of evacuation,and the transfer rule is improved from two aspects of transfer probability and transfer judgment.Taking a highway tunnel in Jiangsu as an example,the parameters are set according to the tunnel scene,traffic composition,traffic volume and evacuation crowd.The crowd evacuation model constructed in Chapter 4 is applied to simulate the crowd in the fire environment.The export work efficiency（OPS）is selected as an indicator to measure the evacuation efficiency,and the K-means algorithm is used to obtain the aggregation center of the small group for the evacuation crowd.According to the characteristic points obtained by the algorithm,the polynomial regression model is used to estimate the relationship between the export efficiency and the fire location,and the boundary line of evacuation channel selection,so as to obtain the optimal channel selection strategy considering the fire location.The crowd evacuation model of highway tunnel in this thesis has certain practical value.The established model can be used to simulate the crowd evacuation in the fire environment of highway tunnel,which provides a scientific basis for highway management and traffic design.The proposed optimal channel selection strategy could provide theoretical support for managers in the tunnel emergency command center to formulate effective evacuation organization scheme and induce diversion crowd measures.