Dynamic Modeling And Analysis Of Emergency Evacuation For Special Crowds

In recent years,the frequent stampede accidents not only have brought huge economic losses to the society,but also seriously threatened the safety of people's lives.Among them,the elderly,the disabled,pregnant women and other special pedestrians in public places often become the biggest victims of accidents due to their poor mobility,which may have an obvious impact on the evacuation of normal people during the evacuation process.Therefore,it is very important to study the evacuation of people with special pedestrians.Based on analyzing the differences of the behavior characteristics among different types of special pedestrians and normal pedestrians,two cellular automata models for describing the evacuation of special pedestrians established,respectively.The corresponding numerical simulations are performed to explore the macroscopic behavior characteristics of pedestrian flow and the generation mechanism of congestion when there are special crowds.In addition,the pedestrian evacuation strategy optimization of the railway station exit with special crowds is also studied in detail.The main research contents are as follows:I.Dynamic Characteristics of Crowd Evacuation under the Influence of Pedestrians with Difficulty in Movement.Based on the general cellular automata model,a cellular automata model for crowd evacuation with mobility disabilities is established,through taking into account the psychological characteristics and behaviors of special pedestrians(mainly pedestrians with mobility disabilities).The numerical simulations are performed to investigate the influence of the proportion and location distribution of special pedestrian on the evacuation process in the hall.The spatio-temporal dynamic characteristic of pedestrian evacuation process is also discussed.The results show that the effect of the special crowd on the whole evacuation efficiency is related to the total pedestrian density.At low density,this effect on the evacuation efficiency is not obvious,but with the increase of density,the proportion of special pedestrians will lead to a significant decrease in the evacuation efficiency.In addition,the location distribution of the special pedestrians will also affect the evacuation efficiency.Especially at high density,compared with the random distribution of the special pedestrians,to put them in a certain position and separate them from the normal pedestrians will reduce the overall evacuation time remarkably.II.Modeling and Simulation of Crowd Evacuation with Blind Persons.Based on the theory of cellular automata,the cellular automata model describing the normal evacuation of a single population is extended to the scene of evacuation with blind people.Based on the analysis of the psychological and behavioral characteristics of blind people,a cellular automaton model of evacuation with blind people is established.The influence of the proportion of blind people and the probability of normal pedestrian assistance on pedestrian evacuation process in the hall under different crowd densities is studied by numerical simulation.The research shows that the bigger the proportion of blind people in mixed population is,the lower the evacuation efficiency is;and helping and supporting the mixed population is conducive to evacuation.III.Design and Analysis of Pedestrian Evacuation Optimization Scheme at Railway Station Exit.As for the exit of the railway station with huge passenger flow,through considering the individual differences of pedestrians,the pedestrians are divided into three kinds: normal pedestrians without luggage,normal pedestrians with luggage,and special pedestrians(such as the elderly,pregnant women,blind people,children,etc).The impact of different evacuation schemes on pedestrian evacuation efficiency at the exit of the railway station are simulated by using Anylogic simulation software.The spatio-temporal dynamics during the evacuation process are analyzed.The simulation results show that the overall evacuation efficiency can be greatly improved by classifying pedestrians in advance and allowing pedestrians to evacuate according to categories.In addition,reasonable allocation of different types of pedestrian access ratio will be helpful for pedestrian evacuation.Finally,the full text is summarized and the problems that need further research are pointed out.