Analysis On Urban Post-Earthquake Fire Spread Model And Simulation Of Emergency Evacuation

The problem of how to minimize damage rate in post-earthquake fire and organize more effective emergency evacuation has gained in importance,since enormous economical and human losses in the recent cases of the post-earthquake fire.Therefore the present research can be beneficial in two main ways.On one hand,it can provide a basic understanding of the dynamic process of fire development and it helps to predict the situation of a certain time of the fire and total area that the fire may spread.That makes possible to estimate the number of firefighters needed and to locate the the most probable places of the greatest damage.On the other hand,it benefits the procedure of the afterwards large-scale emergency evacuation including implementation of transport organizations,improving the evacuation efficiency,and reducing casualties in a sudden catastrophic event.Also this research fits the specific Chinese conditions.The methods proposed can be applied to existing Chinese emergency management system to reduce casualties caused by disaster.Since post-earthquake fire is a complicated and uncertain phenomenon,it is necessary to simplify the relevant conditions and rules and use a schematic model to simulate the whole process.An urban post-earthquake fire spread model has been developed on the basis of cellular automata by using a large number of simple components and through a simple connection and simple transition rules.Using the methods described in the present research makes possible to get a macro point of view of the disaster from diagrams and area maps.The diagram and area maps reflect the degree of fire spread.StarLogo which is a multi-agent technology in visual simulation software is used to simulate emergency evacuation in this post-earthquake fire area and the time difference of emergency evacuation is to be compared between fire accidents and post-earthquake conflagration.The research and the results include the following three aspects:First of all,because of the characteristics of cellular automata,that is simple rules simulation of the complex phenomenon,this paper developed an urban post-earthquake fire spread model based on the components of cellular automata:cellular space,cell state, neighborhood,time and the transition rules.This paper pointed out that the catching fire probability of a cell is closely related to the characteristics of buildings,damage degree and environmental factors,which include thermal radiation,earthquake damage to buildings,open space to prevent fire,the environment etc. Furthermore,the urban post-earthquake fire spread model developed by the author allows evaluating the change of the state of cells over time in progress under the impact of the spread of fire.It helps to obtain the results considering current factors of the disaster that include the wind direction,fire fighting and the fire element,such as open space;that is of great importance for successful outcome.Finally,this dissertation set up a visualized model to simulate the emergency evacuation by one multi-agent simulation software,StarLogo,which uses the similar parallel language: logo.It was found that post-earthquake emergency evacuation takes longer time than fire emergency evacuation,which is caused by roads' damage.