Research On Computer Simulation Of Characteristics And Strategies For High-rising Buildings Occupants’Evacuation

With the urbanization of modern society, more and more high-rise buildings are built all over the world. However, they bring us not only the convenience in life but also great hidden danger to public safety. We all know, once fires or terrorist attacks happen in high-rise buildings, the accidents can develop rapidly, and the evacuation is difficult. If the evacuation strategy is not reasonable, it is very easy to cause a lot of additional loss of life and property. In recent years, the evacuations of lots of structures (such as subway, shopping malls, etc.) have been widely studied, and some research methods, such as the evacuation drill, pedestrian flow investigation, experimental research and evacuation modeling, have been used to study the evacuation of all kinds of buildings. At the same time, some research results also have been applied in the actual evacuation.It is well known that stairs are still the most traditional and only advocated evacuation way to all kinds of buildings. However, accompanied with the expansion of scales, the developments of styles and growing up in height for modern buildings, some drawbacks of the stairs evacuation, such as long evacuation time, poor safety, etc., have been met, furthermore, stairs evacuation is really unfit for the evacuation of those aged, weak, sick, disabled and little. If only the stairs were used for evacuation during those emergencies, most of the occupants would be trapped in buildings for the low evacuation efficiency of stairs. Moreover, some traditional vertical evacuation tools, such as ladder, asylum escalator, slow-down machine, asylum bag, etc. can only meet a few people’s need to escape, and cannot used for those large-scale evacuations, especially the escape in high-rise buildings. Thus, how to make all occupants of buildings to be evacuated safely and efficiently has become a problem which is focused by scholars from all kinds of areas. It is known that the elevator has some virtues, such as, short evacuation distance, less transport time, less energy consumption, etc., thus, how to use the elevator to aid the evacuation in the emergency is with great significance obviously. Fortunately, with the development in the reliability and intelligent of elevator, the elevator will be a kind of effective vertical evacuation facility sooner or later. Thus, it is worth to be deeply considered how to make full use of the elevator to aid the stairs evacuation, and improve the efficiency of the evacuation of high-rise buildings.This paper mainly concerns the problem of researches on how the occupant-merging behavior, stairs structures, characteristics of occupants, evacuation priority etc. influent the evacuation time, and the evacuation strategies with a combination of stairs and elevators. The focus of this paper is to provide some guidance and supports for structure design and occupants management in urgent occupants evacuation on the basis of detailed analysis on occupants merging behavior, evacuation time and occupant-moving characters.Based on some computer means, such as, Pathfinder software simulation, MATLAB algorithm development, data visualization, data analysis, numerical calculation and programming, etc., the merging behavior on merging platform and the characters about the stair-and-elevator-combined evacuation in buildings’occupant evacuation are concerned in the researches of this paper. The main works in this paper includes the following aspects:(1) Research on occupants merging behavior. Under some evacuation requirements, the best merging way is obtained by adjusting the door’s position which is come from the floor and to the merging platform. Furthermore, the influence of stairs structure to evacuation is also researched by doing simulation comparison on staircase of bifurcated type and double-flight stairs, and another situation, which includes some obstacle on the stair, is considered. The results show the anti-obstacle performance of the double-flight staircase is better than that of the staircase of bifurcated type.(2) The problem of evacuation strategies utilize a combination of stairs and elevators for high-rising buildings based on computer modeling and simulation is investigated. Based on considering the characters of occupants, the influence of occupants’characters to combination evacuation is concerned. On the other hand, the evacuation with the priority of lower to upper floors is adopted to do the simulation, and the advantages and disadvantages of lower to upper floors and upper to lower floors are discussed, respectively. The relevant research results are deserved to have some guiding performance to those actual evacuation.(3) The mathematical model of vertical evacuation is established by using mathematical modeling. Based on the obtained mathematical model, the evacuation strategies and methods, which can maintain the evacuation channel unobstructed, are researched. Based on the obtained results, the research is furthered to the optimal evacuation strategy under elevator-stair-combined condition.(4) The influences of the occupants’ panic psychology and surpass behavior on stair or stair-elevator-combined evacuation are discussed by using cellular automation evacuation model.