【作者】 张青松；

【导师】 刘茂；

【作者基本信息】 南开大学 ， 环境工程， 2007， 博士

【摘要】 随着社会的发展,大型社会活动日益增多,人群大量聚集导致的拥挤踩踏事故风险也显著提高。近年来的事故灾害统计分析也表明人群拥挤踩踏事故逐步上升为大型公共聚集场所的主要人为事故灾害类型之一。与火灾等常见事故灾害不同,人群拥挤踩踏事故的发生极其突然,社会影响重大。但各种事故灾害都有其成因机制及发生发展规律,为了防止人群中这种潜在的能量以灾难性的方式释放,需要从理论高度开展对人群拥挤踩踏事故的承载体人群的运动规律及事故致因机理等方面的研究。人群拥挤踩踏事故风险理论研究对于大型建筑性能化设计,人群疏散及管理等有重要应用意义。目前该研究处于起步阶段,仅仅停留在现象表面。本文的研究目的就是通过对人群拥挤踩踏事故风险特征分析提出人群拥挤踩踏事故风险理论并建立相关模型,从而为解释事故成因机制及形成演变规律提供一些有益的尝试及参考。论文着眼于大型人群聚集场所(以体育赛场为例)紧急状况(原发事故已经发生)下的人群疏散过程。依据事故数据及现实观测对疏散人群中的个体移动规律进行深入研究分析,指出在此过程中人群移动经过四个阶段,即人群自由移动、滞留、拥挤及疏散,而事故发生需要经过自由移动、滞留、拥挤和踩踏四阶段,据此从风险的角度提出了人群拥挤踩踏事故风险(四阶段)理论并建立了事故风险理论模型。人群拥挤踩踏事故风险理论模型的求解涉及因素众多,目前对于理论模型中的滞留阶段基于人群流量与人群密度关系建立了时间维变量的滞留人数定量模型(SCM),用于计算人群疏散过程中“瓶颈”区域内随时间变化的滞留人数,并通过滞留人数与总的容纳人数之比来预测人群拥挤踩踏事故发生概率。但对于事故风险的后果即人群伤亡很难利用数学定量方法求解,因此本文针对理论模型中的拥挤阶段建立了人群拥挤微观模拟模型。人群拥挤微观模拟模型是在经典“社会力”模型基础上,根据对人群拥挤踩踏事故特征分析,引入“拥挤力”的概念来解释拥挤踩踏伤亡后果致因,即个体“拥挤力”积累到设定阈值并持续一段时间个体即死亡。研究分析表明“拥挤力”与“心理排斥力”不同属于真正力学意义上的作用力,并依据动量定理结合“磁场力”模型对个体“拥挤力”进行建模分析。微观模拟模型的实施需要计算机模拟技术,本文依据多智能体(MAS)整体建模方法构建了人群拥挤踩踏事故模型系统的层次结构,目前设定了赛场环境和观众两类智能体(Agent),并给出人群拥挤踩踏事故模拟机理。结合人群拥挤微观模拟模型在多智能体模拟平台NetLogo上开发了大型赛场出口人群拥挤踩踏事故模拟系统(CroC&Ts-Egress)。论文实例选取天津奥林匹克中心体育场某看台出口,从以下三个方面进行应用研究:一是针对人群拥挤踩踏事故风险四阶段理论中滞留阶段,应用本文提出的滞留人数定量模型(SCM)对体育赛场看台不同宽度出口人群疏散实例计算;二是基于人群流动理论和离散计算方法对传统疏散时间计算公式进行了改进,并提出了疏散离散时间计算模型(EDTM),运用此改进模型对天津奥林匹克中心体育场某看台出口人群疏散时间计算,并与BuildingEXODUS计算机模拟、传统公式计算结果对比分析;三是利用本论文开发的人群拥挤踩踏事故模拟系统(CroC&Ts-Egress)通过设定不同的方案主要针对不同赛场出口宽度进行模拟,通过模拟结果分析表明,CroC&Ts-Egress可以很好的解决SCM不能计算事故风险后果的问题,并通过模拟结果对SCM计算结果推理进行了验证分析,表明SCM定量计算推理与CroC&Ts-Egress模拟结果是一致的。更多还原

【Abstract】 In many large crowd, there is a potential for injury and even loss of life rusulting from the dynamics of the crowd’s behavior. Given the increasing number of large-scale sporting events, religious gathering, and rock concerts with time, the issue of crowd safety is of growing importance following the society development. The many crowd-related disasters (that is, fatal accident) over the past decade have demonstrated the possible lethal consequences of large gatherings of people. The happen all at once and the consequence is serious with crowd crushing and trampling accident contrast to fire. But every accidents and disasters have the interior law, we must develop the study for the crowd crushing and trampling in theory to avoid the potential energy release in the gathering people.The mechanics of human crowds is complex. The theory study for the crowd crushing and trampling accident is very significance for the building performance-design, crowd evacuation and management. The aim of this study is putting forward the crowd crushing and trampling acciednt risk theory and establish the risk model.Through the accident data and observation in scene we have a in-depth study to the individual move rule. And indicating the individual move pass four phases in emergency: free move, stranded, crushing and trampling if accident happen. And if crowd evacuation safely four phases of individual move including free move, stranded, crushing and evacuation. The stranded and crushing are the important phases for the crowd crushing and evacuation accident. Hereby crowd crushing and trampling accident risk (four phase) theory was put forward and the relational risk theory model was modelled.The risk theory model isn’t able to solve in current phase. A Stranded Crowd number quantitative Model (SCM) was put forward based on the relation of crowd flow and density. We can calculated the probability of crowd crushing and trampling risk through the SCM calculated results divided by total design people number. But the consequence of risk couldn’t resolve with the mathematic method, so the crowd crushing microscopic simulation model was found based on the‘society force’model. The‘crushing force’was put forward to explain the cause of crowd casualty during the evacuation process, and we can solve the‘crushing force’model through the momentum theorem with“magnetic force”model.The implement of microscopic simulation model need the computer simulation technology. We construct the hiberarchy of crowd crushing and trampling simulation system through the technology of MAS. Combine the crushing micrososmic simulation model develop the Crowd Crushing and Trampling Simulation system for Egress (CroC&Ts-Egress) with cross-platform multi-agent programmable modeling environment‘NetLogo’.The application of all the models is the egress of Tianjin Olympic Center Stadium, and three parts are included in this paper. First, we calculated the stranded crowd number with SCM in the egress area; Second, a computational Evacuation Discrete Time Model (EDTM) has been presented to analyze the building egress evacuation time problem with previous works, and a comparison of EDTM, previous model and computer simulation indicates that both the EDTM and the simulation curves were found to give better predictions than the previous model; Third, a simulation was utilized with CroC&Ts-Egress for the different width egress, the simulation results contrast to the SCM calculation results indicate there are the same.更多还原