Pedestrians Evacuation With Fire Spreading Based On Cellular Automaton Model

With the high development of the society, the expansion of the urban, and the growth of the population, the number of large buildings, squares, halls and other public places increases rapidly. In the public places, the event of fires and other disasters can easily cause a large number of casualties. In recent years, many scientists have studied the evacuation dynamics in public places, and analyzed the properties of the pedestrians who are in the case of the fire spreading. This paper does the further research. A model based on cellular automaton is introduced to study the evacuation under the fire, and the model is more realistic. The effect of the several factors (such as the fire spread rate) on the evacuation under the fire is discussed, and the influence of the exit choice behavior on the evacuation is also studied. The main contents of the paper are as follows:1. This paper introduces an extended FF (floor field) model considering the characteristics of the pedestrians under the fire spreading. This model is used to analyze the effect of system size and layout of exits on the evacuation. The simulation results show that:the evacuation time increases with the growth of density and the enlargement of the system size, the uniform exits layout is benefit for evacuation when the fire occurs in the middle of the system.2. The new extended FF model in this paper is used to simulate different scenes and analyze the pedestrians'behavior. This paper studies the effect of series of factors on evacuation and the factors contain whether the obstacles existing, the number and layout of the exits, the rate of the fire spread, the value of the fire floor field, the site of the fire occurred, the distribution of the obstacles.3. The simulation using the existing models has some shortcomings:the uneven distribution of the exits (the original layout of the building or affected by the fire) causes the uneven distribution of the pedestrians before each exit, which can result in the inefficient evacuation of some exits. But, in the reality, the pedestrians will choose their path considering the number of pedestrians before each exit and they have exit choice behavior. This paper proposes two options to solve this problem:proposing an extended FF model considering the exit choice behavior and adjusting the value of static floor field to balance the number of pedestrians attached to each exit. The results show that the evacuation time is smaller when considering the exit choice behavior and it is more realistic.