障碍物对房间人群疏散过程影响的宏观模拟研究

Macroscopic approach for modeling the effect of obstacles on room evacuation process

公共建筑内随机分布的障碍物可能对突发事件下密集人群疏散过程中人员速度、路径选择行为产生影响。考虑较为密集人群疏散过程与宏观流体流动过程的相似性,用连续性方程描述人群密度变化过程,结合障碍物对人员运动行为的影响,建立了考虑障碍物影响的人员疏散宏观模型。采用该模型计算重现了疏散出口附近的高密度人群拱形和椭圆形分布,定量分析了障碍物以不同概率分布于建筑内不同位置时对疏散过程中人员密度演化以及完成疏散所需时间的影响。

The presence of obstacles in public buildings may affect the moving velocity and direction choosing behavior of pedestrians during the mass evacuation process in the case of abnormal situation. Considering that the flow of mass pedestrians seems similar with the flow of fluid, the continuity equation which is used to describe the fluid flow can also be applied to quantify the pedestrian evacuation. By taking the effect of obstacles on pedestrian moving characteristics into account, i.e. slowing down the speed and thus then changing the direction choosing behavior, a mathematical based macroscopic room evacuation model was established. After discretizing the model by using weighted essential non-oscillation （WENO） method, the numerical simulation of room evacuation was performed. Results of the simulations indicated that the model can well reproduce the distribution of pedestrians near the exit, i.e. the clogging and arching phenomena. Meanwhile, the model can also quantify the density evolution process during the evacuation as the result of the presence of stochastic obstacles. Finally, the time needed in completing the evacuation when the obstacles with different size distributed in different regions of the room were also calculated and analyzed. The findings showed that the presence of obstacles far away from the exit will slow down the evacuation, while the presence of those obstacles near to the exit will cause complex influences. The obstacles will mostly slow down the evacuation. However, with proper allocation and size distribution, the obstacles can speed up the evacuation process in contrast, which means the obstacles in passageways of public buildings should be carefully allocated.