Student Population Model Based On Cellular Automata Evacuation Studies

Recently, with the increasing educational input, more and more childrenhave access to education. However, the safety problem in campus is graduallybecoming prominent. Especially the frequent crowding accidents caused by theunexpected events, such as earthquakes, fires, violence, etc. result in heavycasualties. So, how to reduce casualties in emergency evacuation has become animportant research topic of relevant scientific research institutions andadministration. In this paper, based on the existing cellular automaton model forpedestrian flow, the improved cellular automaton models are proposed toinvestigate students’ evacuation process by considering the students’ behaviorcharacteristics, psychological factors and the specific buildings’ structure andsetting up the students’ movement rules reasonably. The numerical simulationsabout the students’ evacuation process in different buildings are performed andthe effects of various factors on students’ evacuation efficiency are explored.Moreover, we put forward some suggestions for the planning of campusfacilities, and management and control of pedestrian flows qualitatively. Themain contents of the dissertation are as follows:(1) Through analyzing the students’ special psychological and behaviorcharacteristics in emergency evacuation such as surpassing others, intelligentchoice, panic behavior, going first in the front row and the individual differences,the cellular automaton model describing students’ evacuation in the classroom isestablished. The effects of the classroom exit location, the desks’ distribution,the ratio and position of students with strong movement ability on evacuationtime are discussed. The numerical results show that: the evacuation efficiency isthe highest when two exits become closer to a certain extent and being too far ortoo close is unfavorable for evacuation. As a general rule, when there is morespace close to exit wall and the desks are loose, student evacuation time is less.When the ratio of strong ability students is about25%and they are far awayfrom the exits, the evacuation efficiency can be improved apparently(2) The above model is extended to the process of students’ evacuation in the whole building. Let Building No.16in Taiyuan University of Science andTechnology as an example, numerical simulation are performed to study theeffects of various factors on evacuation time such as the individual floor’sdensity, stair width and stair structures. In addition, as for the jam during thebreak, the influence of students’ convection is explored and the relativelyoptimal evacuation strategy is obtained. The numerical results show that: theevacuation time is shorter when students are evenly distributed in each floor ormore students are distributed in lower floor; the evacuation is the mostreasonable when stair width reaches a certain value, and then evacuation timemakes little difference with the further increase of width. The different stairstructure has little impact on Building No.16, however, the evacuation withsingle stair is faster than that with double stairs in former evacuation and slowerin later periods. Considering the typical case of break between the classes, thephenomenon of students’ convection can be observed, and when the studentsupstairs should make the way for those students downstairs, or avoid thepushing hour as possibly as they can, the evacuation efficiency is highest.(3) The evacuation process under the restricted sight in emergent eventslike power cut is investigated. A case study is presented for students’ evacuationfrom No.1student canteen in Taiyuan University of Science and Technologywith an improved cellular automaton model. The different movement rules indead zone and visible zone are adopted. The influence of different side doorlocations, individual personnel density and evacuation instruction signs onevacuation efficiency are explored. The numerical results show that it isbeneficial for evacuation if the side doors are relatively further from the mainentrance door. The evacuation time decrease with the decrease of the totalnumber of students. Under restricted sight, evacuation signs can significantlyimprove evacuation efficiency.The final chapter of this dissertation is devoted to a summary of the thesisand a prospect of further study of the pedestrian flows.