Numerical simulation of the fire emergency evacuation for a metro platform accident

Abstract

A coupled analysis of agent behavior and Computational Fluid Dynamics (CFD) model is applied to investigate the fire evacuation effectiveness in a popular metro station in Guangzhou, China. Due to the high density and complexity of traffic, the concept of Required Safe Escape Time and Available Safe Escape Time (RSET/ASET), which is more flexible and adaptable than the “6 minutes” principle, is applied in the safety assessment of fire evacuation. To pursue a stable simulation of the coupled model, the standard Critical Radiant Flux is used to deter the tenability criteria for exposure to fire and heat. Various related factors, including the fire location, the Heat Release Rate (HRR) of fire, the crowd density, and the operation mode of escalators, are analyzed through a series of simulations. Results indicate that the interaction between fire and humans should not be neglected in the evacuation simulation. Both the fire location and the crowd density have a significant effect on the evacuation, while the HRR of fire has a minor impact. When the accident happens at the entrance of an escalator, RSET is 58.3% longer than that when the accident occurs in the middle of the platform. RSET grows with the increase of the crowd density linearly. Besides, the evacuation efficiency could be partly improved by changing escalators that usually operate in the descending mode into ascending mode.

The role of crowd behavior and cooperation strategies during evacuation

“…33 Related research of evacuation modeling and simulation which implements different aspects of game theory such as a spatial game in describing risky agents is proposed by Pa ¨rna ¨nen, 10 game theory cost function modeled using distance to the exit and number of agents is proposed by Tian et al, 33 game theory for room evacuation via lattice gas scheme can be found in Bouzat and Kuperman's study, 34 game theory via a CA environment to study patient and impatient agents are presented by Helio ¨vaara et al, 35 von Schantz and Ehtamo, 36 while game theory to study the effect of obstacle removal during evacuation is presented by Lin and Wong. 37 In modeling and simulating evacuation scenarios, it is essential to take account of the crowd's behavior and diverse emergency scenarios as pointed out by Wirz et al 38 Examples of several recent research works on diverse emergency evacuation scenarios are featured such as in metro station, 13 terminal apron, 39 training school, 40 and also during dense crowd. 41 Xie et al 13 proposed a stabilized coupled model of agent behavior and computational fluid dynamics model for effectiveness investigation of the fire evacuation in a metro station.…”

“…The simulation of evacuation requires the capability to model individual decisions and behaviour 10 throughout the escape process such as during a stampede, 11 which is strongly affected by the surroundings 12 such as fires, [13][14][15] smoke conditions, 16 and earthquakes 17,18 . The understanding of human behaviors can minimize the chances of crowd calamities 19 and lead to an effective evacuation.…”

Experiment, model, and simulation of the pedestrian flow around a training school classroom during the after-class period

“…(1) The spatial distance between his/her current location and expected destination (2) The attraction between him/her and his/her adjacent pedestrians (3) The impacts of other pedestrians and obstacles (4) The attraction caused by the corresponding adultchild pair…”

“…In recent years, scholars have conducted extensive and indepth research on crowd evacuation. [1][2][3][4][5] For example, for the evacuation of dense crowds, Hesham and Wainer 1 presented advanced models based on centroidal particle dynamics (CPD), an agent-based short-range collisionavoidance model for pedestrians in dense crowds. Their models can reproduce visually convincing emergent crowd phenomena.…”

“…Their models can reproduce visually convincing emergent crowd phenomena. For the evacuation under fire conditions, Xie et al 2 extended computational fluid dynamics (CFD) model to investigate the fire evacuation in a metro station, and they claimed that their model can contribute to the emergency management; Yuan et al 3 proposed an extended social force evacuation model considering the effect of emergency signs, and simulation results of their model can help to design the layout of emergency signs. For the evacuation of multistorey buildings, Liu et al 4 carried out a 3D visual simulation enabling the simulation of building evacuation more realistic; Al-Habashna and Wainer 5 adopted Cellular Discrete EVent System Specification (Cell-DEVS) to simulate multiple-floor buildings' evacuation.…”