Research On Decision Making For Emergency Evaluation In Buildings With Multi-Exits Based On Optimization Theory

With the development of society, more and more people will appear in various venues, such as stadiums, shopping malls, convention centers, theaters, etc. Such buildings belong to venues where the crowd density is very high. When some emergency events or disaster incidents occur there, emergency evacuation is essential for groups. The study for crowd emergency evacuation is of great practical significance and helpful for social security. Crowd emergeny evacuation is the basic of building design and emergency rescue, and therefore has been the hot spot for the domestic and international researchers.Many experts have done a lot of research for the crowd emergency evacuation in the building for many years, especially for the crowd movement and the crowd's behavior badsed on quantitative simulation methods. The exiting research was made based on the special behavior survey and statistics, and the research methods can fall into two categories:one is to make evacuation experiment in the real scenario by some animals or people, and the other is to make a mathematical model or to do crowd evacuation simulation by computer. Considering the cost of ethical and moral factors of the evacuation experiments by animals or people, we can know that a mathematical model based on the optimization theory will become an important method for the study on crowd emergency evacuation.Based on the optimization theory, we explore the crowd flow mechanism in crowd evacuation, study overall evacuation time, and study the evacuation decision problem for different exits. Discussion on the relations between evacuation velocity and crowd density is presented in detail by making an optimization evacuation model. Given a certain evacuation scenario, calculating the evacuation time and making the allocation for each exit based on the optimization evacuation model and simulations by the evacuation software buildingEXODUS(v4.06) can be obtained as well as the comparative analysis for the two results. As a result, we can see that the result of the evacuation optimization model can be helpful to the evacuation management and the related evacuation decisions that can make all exits used well, and therefore evacuation efficiency can be enhanced.The results of the study are helpful to manage the crowd evacuation in the buildings. If some emergency events or accidents occur there, it also helps safety managers evacuate pedestrians as soon as possible, which reduces the amount of casualties.