Death in Crowds

Study on the collision dynamics and the transmission pattern between pedestrians along the queue

“…The collision dynamics equation indicates the complicated relationship between the impulse L 1 exerted on the pedestrian and the impulse L 2 transmitted from this pedestrian to the others. That is to say, if the impulse exerted on the pedestrian has been given already, the impulse transmitted to the next pedestrian in the collision will be calculated by the equation (14). Therefore, the transmission pattern of the collision can be elucidated and predicted by this collision dynamics model.…”

“…Supposing that the momentum of the backmost one has been completely converted into the impulse transmitted to the 2nd pedestrian, it will be consistent with the successive collision process in Condition 1. Therefore, the impulse exerted from the 3rd to the 6th pedestrian can be successively derived by equation (14) with parameters of equation (30) and contact forces will be calculated by the numerical relationship in figure 5. The maximum contact force F Max exerted on each pedestrian in this simulation is given by three methods above, and the results are shown in table 3.…”

“…In Condition 1, equation (14) has been derived to elucidate the relationship between the impulse exerted on the pedestrian and the impulse transmitted form this pedestrian to the next one. It should be noted that the centroid distance between two pedestrians d is changed to dierent distances.…”

“…According to the research literature and investigation reports [4][5][6][7][8][9], when the crowd density is rather high, the interaction between pedestrians will occur frequently, such as pushing, collision and squeezing, even resulting in crowd turbulence [10] or crowdquakes [11]. Generally, some researchers refer to 'crushing' or 'trampling' or a combination of both as the mechanism resulting in causalities and fatalities [12][13][14]. Regarding the cause of death, compression asphyxia caused by sustaining chest compression and instantaneous violent trampling is identified as the main reason leading to the death of most victims in the two categories of accidents above [15][16][17].…”