步行设施内障碍物的瓶颈阻滞与隔离保护机理

Internal spatial obstacles in walking facilities can act as a movement bottleneck to affect rational pedestrian flow and a safety barrier to protect panic pedestrian in crowds. Therefore, the mechanism of spatial obstacles with bottleneck and protection function is a hot topic in the research field of the organization and management of pedestrian flow. The study on the function of obstacles with bottleneck and protection is carried out based on micro-behavior simulation of pedestrian dynamics with internal obstacles. First, through analyzing the selections of pedestrian micro-behavior under the condition with internal obstacles, these influences of obstacles are revealed respectively on rational pedestrian dynamics including varying spatial demand, friction and repellant, collision avoidance and so on, and on panic pedestrian dynamics including push-force being absorbed and terminated, bottlenecks capacity, route choice strategies and so on. Second, the integrated simulation model under the condition with and without obstacles is established based on Dynamic Parameter Model using cell automata(CA), which simulates the macro-characteristics and phenomena of pedestrian flows with internal obstacles. Third, based on computer simulation and practical observation, key factors and critical points of affecting obstacles function with bottleneck and protection are analyzed. The formation mechanism of obstacles with bottleneck and protection function is explored, in which the relationship between the bottleneck and protection function are established. Finally, design principles and evaluation indexes of pedestrian flow organization and internal obstacles layout in walking facilities are founded. Research achievements could provide basic theories and technical supports to raise the efficiency of pedestrian movement and to prevent pedestrian stampede-crush occurring in walking facilities.

步行设施内空间障碍物具有对行人流正常移动效率的瓶颈阻滞作用与恐慌拥堵隔离的安全保护作用，是行人交通流组织管理等领域的研究热点。以存在障碍物条件下的行人流动态特征为研究对象，基于微观行为仿真发掘障碍物瓶颈阻滞与隔离保护的作用机理。分析存在障碍物条件下行人流的微观选择行为；揭示障碍物对正常行人流动态空间需求、障碍物摩擦排斥、冲突避让绕行等，以及对恐慌行人流拥挤力吸收终止、瓶颈通过能力、路径选择策略等的影响机制。建立基于元胞自动机的集有无障碍物于一体的行人流动态参数仿真模型，再现存在障碍物条件下集散行人流的宏观特征与现象。基于仿真和观察分析影响障碍物瓶颈阻滞与隔离保护作用的关键因素及其临界值，发掘障碍物瓶颈阻滞与隔离保护的作用机理，及二者的内在联系；提出步行设施内行人流组织与障碍物布局的方案设计原则与综合评价指数。成果可为提高步行设施内行人移动效率和预防拥堵踩踏等提供理论基础与技术支持。

大型行人步行设施设计以及行人集散组织管理，需要掌握空间障碍物对行人流正常移动效率的瓶颈阻滞作用与恐慌拥堵隔离的安全保护作用。为发掘空间障碍物的瓶颈阻滞与隔离保护机理，指导步行设施空间障碍物布局，项目从步行设施内行人避让障碍物、恐慌拥挤踩踏、拥堵静态交通流分配、设施通过能力、导向标识设置、功能区布局等角度开展研究。. 主要创新点包括：引入障碍物阻滞系数、行人移动概率，构建了集有无空间障碍物于一体的行人流动态参数仿真模型。基于拥挤人群中的拥挤力与摩擦力特征，以及行人移动冲突，构建了空间细分的元胞自动机与作用力相融合的拥挤行人流仿真模型。构建了基于Voronoi图的启发式行人流微观仿真模型，嵌入了行人动态空间需求，空间移动、绕行和跟随、微观防死锁、位置微调等机制。针对静态拥堵交通流分配，引入次生瓶颈、拥堵干扰与渗透、分段路段阻抗、拥堵区域识别、需求加载机制等概念，提出了考虑拥堵空间排队与溢出的静态交通流分配的用户均衡原理，以及相应的增量分配与迭代加权求解算法。构建了基于拥堵与畅通静态交通流分配的网络通行能力计算模型。提出了基于功能区布局与乘客流线组织的导向标识内容与位置的设置方法，以及基于行人流与活动链的综合客运枢纽功能区布局模型。. 主要研究结论包括：从理论上证明了行人移动概率的合理性，模拟再现了行人移动过程中“与通道壁保持一定空间距离”“倾向于选择更宽移动通道疏散”“多串联瓶颈中最窄瓶颈主导”“瓶颈前扇形聚集”“行人拉链现象”“转弯区域隐形瓶颈”“成行移动”“障碍物前后菱形区域”等宏观现象。发现行人流拥挤踩踏空间上呈现环出口集中分布，并具有一定的时间滞后性。提出了在全局区域内选择最短路而在局部拥堵区域内选择最长路的“极小极大”需求加载路径选择机制，以有效逼近用户均衡状态。构建了通行能力计算模型，不再需要预设固定的OD需求模式，计算得到的路网通行能力只依赖于路网拓扑结构与路段属性数据。