Experimental Study On Pedestrian Dynamics In The Presence Of Obstacles That Can Be Stepped Over

To explore the pedestrian dynamics and the characteristics of pedestrian evacuation,and to better solve the problem of pedestrian congestion,a large number of experts and scholars have carried out a very in-depth study on pedestrian flow.However,among these studies,the influence of obstacles which can be stridden over on pedestrian evacuation and pedestrian flow is rarely discussed.In the real world,there are many dwarf objects,which can become obstacles if they fall down to the ground in the evacuation,such as chairs,stone and even tumbled pedestrians.Therefore,this project started to carry out an experimental study on pedestrian dynamic characteristics with a bar-type obstacle which can be stridden over.pedestrian evacuation experiment and the pedestrian dynamics experiment in single-file movement were carried out respectively.By means of mathematical statistics,through the analysis of several indicators such as evacuation time,local instantaneous density,pedestrian decision-making behavior and the relationship between pedestrian speed and time gap,the influence of obstacles which can be stridden over on pedestrian evacuation and pedestrian flow was investigatedIn the pedestrian evacuation experiment,the evacuation time decreases along with the increase of the distance between obstacle and exit.From the perspective of the local instantaneous density,the height of the obstacle will lead to different cluster distribution.As for the pedestrian decision-making behavior,as the distance between obstacle and exit increases more pedestrians prefer to pass by the obstacle.In the pedestrian dynamics experiment in single-file movement.As the height of the obstacle increases,the phenomenon of ‘speed demarcation' becomes more and more clear.In terms of the basic relationship between density and velocity,in the region of high density,due to the acceleration and deceleration effect brought by the obstacle,pedestrian speed in the condition with the obstacle will exceed that in the condition without the obstacle.This paper also studies the relationship between pedestrian speed and time headway under all conditions.It is worth noting that the results show for the conditions with the obstacle,only the strongly constrained regime and the free regime exist,and the weakly constrained regime only exists in the conditions without the obstacle.