Experimental And Simulation Study On Evacuation Considering Behavior Characteristics Of Small Groups

In recent years,with the development of economy and society,more and more large-scale buildings and crowd gathering activities are frequent.Under the emergency,emergency evacuation is an important defense line to ensure the safety of people’s lives,and also an important part of public safety management.Some studies have shown that the basic unit of crowd evacuation in public places is not individual,but small group.Due to the social attributes of human beings,in emergency,people tend to evacuate with people with social relations and even strangers.In order to organize evacuation reasonably and efficiently and reduce casualties and property losses,the decision-making behavior and movement law of small groups are the key to study.In this study,the first floor to the third floor of the school of logistics engineering of Shanghai Maritime University is selected as the evacuation area to carry out the small group evacuation behavior experiment,and then the pedestrian evacuation process modeling is carried out by using the anylogic simulation platform,and the sensitivity analysis of the influencing factors of decision-making behavior is carried out,and then the strategy suggestions of crowd evacuation in the building are put forward.The main research results are as follows:(1)The pedestrian evacuation experiment in complex building layout was carried out.Starting from the two aspects of small group size and familiarity with buildings,this paper collects and collates relevant experimental data,and analyzes the movement performance of small groups in different evacuation scenarios,such as exit,route selection behavior,pre decision behavior,decision-making time and evacuation speed.It is found that people’s choice of exits and routes is significantly affected by their familiarity with the building.Those who are not familiar with the building layout tend to choose the direction of descending from the stairs or having better visibility.Those who are familiar with the building layout may have leadership behavior,The team familiar with the building layout will choose the shortest evacuation route and the nearest emergency exit.In terms of evacuation speed,the speed of small groups is slower than that of individuals,but there is no significant correlation between the size of small groups and evacuation speed.At the same time,those who are familiar with the architectural layout are faster than those who are not.In the process of evacuation,small groups of evacuees often make pre decision before reaching the decision point.In terms of decision-making time,individual decision-making time is less than small group decision-making time,and small group discussion behavior will increase small group decision-making time,which will affect evacuation efficiency.(2)Based on the analysis of the experimental data,different types of small group decision-making behavior rules are summarized.The probability calculated by decision-making behavior rules is used as parameter input,and a crowd evacuation model conforming to the characteristics of small group evacuation behavior in building layout is built in the anylogic platform.The simulation results are compared with the experimental results to verify the effectiveness of the decision rules and the simulation model.(3)Taking the complex three story building as the simulation scene,the decision rules of small groups in the evacuation process of the building as the input,through changing the personnel’s familiarity with the building,the visibility conditions of each corridor,increasing the guiding behavior and other influencing factors,several typical scenarios are constructed to explore the law of small group selection behavior.It is found that the decision-making rules of unfamiliar groups seriously affect the evacuation efficiency;Improving the visibility of the corridor can reduce the phenomenon of pedestrians clustering to choose a path or exit,disperse the evacuation crowd and reduce the evacuation time;Increasing route guidance behavior,especially increasing the corresponding evacuation instructions at the location of vertical evacuation facilities,can reduce the phenomenon of people choosing stairs to go down,avoid stair congestion and improve the evacuation efficiency.(4)Based on the results of crowd evacuation experiment and simulation analysis,this paper proposes the emergency plan and relevant countermeasures for the crowd emergency evacuation in complex buildings,in order to provide decision support for crowd evacuation management and building emergency evacuation scheme optimization.