拥堵疏散的行人拥挤力仿真研究

基于元胞自动机仿真研究拥堵疏散条件下行人拥挤力的产生、传递、吸收、抵消、累积等过程, 以安全出口前拱形的拥挤疏散行人流为研究对象, 研究拥挤致伤的生成机理. 基于行人位置距安全出口的距离, 生成趋于安全出口方向的拥挤力; 引入拥挤力效果与合力参数, 分别描述外界拥挤力对个体行人的作用效果与作用合力; 引入吸收系数与抗死伤系数, 分别描述拥挤力传递过程中行人对外界拥挤力的吸收与抵抗能力. 研究表明, 随吸收系数或抗死伤系数的增加, 能有效预防疏散行人流的拥挤致伤; 存在临界吸收系数与抗死伤系数, 将系统区分为弱保护相位、强保护相位和完全保护相位; 拥挤的死伤数量随疏散行人数量的增加而增加; 而且, 拥挤致伤的危险区域在安全出口前以安全出口中心线为对称轴呈“倒钟”形分布.

Simulation of pedestrian push-force in evacuation with congestion

The simulation of pedestrian push-force in evacuation with arched congestion before exit is presented based on cell automata. The generation, absorption, transfer and gather of pedestrian push-force are analyzed. Initial push-force facing to exit is generated based on the distance between pedestrian and exit. The scalar and vector sum of push-force are introduced to respectively describe the push effect and resultant force of outside jam push-force in crowded evacuation. Absorption coefficient and anti-crush coefficient are introduced to respectively describe the ability for pedestrian to absorb and resist the outside jam push-force. Simulation results show that the increase of absorption coefficient or anti-crush coefficient can effectively prevent pedestrian from being injured. It is found that three phases: weak protection, strong protection and complete protection are distinguished based on two critical absorption coefficients and an anti-crush coefficient. Pedestrian casualties will increase with the number of evacuation pedestrian rising. It is also shown that pedestrian casualties in jam occur in a reverse bell-shape symmetry zone before exit.