Experiment And Simulation On Pedestrian Evacuation Characteristics With The Constrains Of Stair Steps

High-rise buildings and underground multi-story buildings are increasing rapidly in recent years.The diversification of structure and functions bring convenience to people's daily life,and also bring unprecedented challenges to emergency evacuation.These buildings are densely populated with complex structures.In case of fire,earthquake and other unconventional events,a large number of people need to be evacuated to safe areas.Staircase is the only vertical passage in the emergency evacuation of buildings,and the particularity of the staircase structure,the movement of the crowd on the stairs is significantly different from the movement in the horizontal passage,so it is of great practical significance in the safe evacuation of stairs and formulate scientific evacuation strategies.In this thesis,for different types of long-distance stairs(corner stairs and straight stairs)in high-rise buildings and deep underground buildings,in order to explore the performance of individual evacuation on long-distance stairs,the individual upward and downward movement tests on long-distance stairs were carried out respectively for corner stairs in high-rise buildings and straight stairs in underground stations.In addition,for exploring the characteristics of stair evacuation of people,based on the individual evacuation performance in the previous experiments as the basic parameters,and based on the multi grid discrete model,a stair evacuation simulation model is established.The specific research contents are as follows:First,the experiment of personal evacuation(movement)on the corner stairs was carried out in a public building.This part mainly analyzes the time-space characteristics,individual movement speed and physiological changes of pedestrians before and after the experiment.The results show that the step pattern has a great influence on the physiological performance and behavior when they are moving up and down long stairs,especially when the light is dark at night.Before and after the experiment,people's physiological functions changed greatly.Then,the personal evacuation experiment is carried out on the straight stairs of the subway station,and the experimental results are recorded and discussed.Experiments show that in the underground space,there is a significant difference between the upward evacuation performance and the downward evacuation performance.The average speed fluctuates periodically along the evacuation route.Age and gender have significant effects on speed,evacuation time,and physiological changes.Most of the participants chose the middle area to go upstairs,which shows that walking in the middle area is the most comfortable way in this study.The use of handrails did not improve the efficiency of upward movement.Finally,for the evacuation of stairs in high-rise buildings and deep underground buildings,considering the constraints of stairs and the impact of stair buffer platform,the evacuation model of stairs is established.The results show that the stair platform does play a buffer role in crowd movement,and the length of stair platform has a more obvious effect on evacuation efficiency.Without platform,the density flow diagram is similar to "parabola",with platform,the density flow diagram is similar to "trapezoid"The results of this study are conducive to further understand the movement and behavior characteristics of evacuation individuals on the long-distance stairs.The basic data obtained from the actual measurement experiment can provide a basis for the development and verification of evacuation model.The overall research work can provide some suggestions for the safety management of evacuation in the vertical direction of high-rise buildings or deep underground buildings.