基于时间着色Petri网的建筑火灾疏散系统建模与仿真

为缓解建筑火灾疏散时间长且效率低问题,基于时间着色Petri网的理论,针对某建筑的结构特点进行建模并进行性能分析。通过算法计算与分析,合理规划不同类型人员的不同疏散通道选择,并对模型进行时间模拟仿真,提高建筑内人员疏散效率。提出带有建筑火灾疏散因素的管理疏散方法,增加相关的颜色集和时间戳,并在原模型中融入算法计算,模拟火灾疏散时间,并提出不同类别人员疏散引导的方案。达到疏散用时更短、效率更高、伤亡率更低的目标。实验结果表明,相比于其他模型,融入管理疏散算法的时间着色Petri网模型,人员平均疏散时间降低6.9 s,具有较高疏散效率。     

基于改进ACO算法的建筑疏散路径优化研究

针对大型公共建筑存在的结构复杂、消防疏散困难等问题,提出了用于优化疏散路径的改进蚁群算法。首先,针对基本蚁群算法(ACO)引入Dijkstra 算法,并利用Dijkstra 算法计算出全局性较好的次优路径进而对蚁群算法初始信息素分布情况进行了加强。其次,根据火灾的实时情况改进了蚁群算法的转移概率、更新规则、信息素挥发系数、启发函数等。最后,对改进的蚁群算法进行对比仿真实验。实验结果表明该算法具有较强的全局搜索能力以及较高的搜索效率,能够避免算法进入局部最优陷阱,有效提高消防疏散路径规划效率。     

Study of announced evacuation drill from a retail store

Study of evacuation from fire is always focused on evacuation models, but rarely on evacuation experiments. This paper presents the results acquired from an announced evacuation drill of XIN LIAN XIN Store in China. There are two floors and five emergency exits in the building. Most of the customers knew there would be an evacuation drill before they entered the store, but they did not know the exact beginning time. The video of the whole evacuation process was recorded using television cameras installed in the store. The customers who evacuated from the store were asked to complete a questionnaire by researchers positioned outside the five exits. Analysis of the videotapes provided information on total evacuation time and actual number of customers who evacuated from the store. Questionnaires present the information on customer characteristics, primary behavior at alarm, pre-movement time and exit choice. The analysis results show that pre-movement time is an important part of evacuation process. Strengthening detector, alarm equipments and staff training are very effective and necessary for fire safety in China. These data can also be used as input parameters for evacuation models in performance-based fire protection design or validating the evacuation models' accuracy.     

公铁合建越江隧道列车运动压力波数值模拟

本文采用CFD方法对地铁通过公铁合建越江隧道产生的压力波进行了数值模拟分析。基于国内某公铁合建越江隧道相关尺寸建立其下部地铁隧道三维几何模型,采用动网格方法模拟列车从驶入到驶出隧道的全过程。利用国外模型实验数据验证了本文数值模拟方法的可靠性,根据隧道内压力变化曲线,分析了由于列车通过隧道引起的压力变化规律。计算得到进入疏散通道防火门处的压力峰值,最大值1910Pa,最小值-1060Pa,与疏散通道内30~50Pa的正压有较大的压力差。     

基于人员疏散特征的商场火灾应急管理策略研究

分析商场火灾特点并进行商场火灾风险分析。以广东省茂名市某商场为原型,建立基于 Dijkstra 算法的商场疏散模型,计算疏散时间,分析影响应急疏散的关键因素,从商场环境布局与管理、人员疏散指挥、火灾应急演练等三个方面优化商场火灾应急管理策略。研究结果表明：商场三个楼层的最短疏散时间分别为 83.1、85.5、145.6 s,采取优化措施后示例区域的平均疏散时间减少了 8.9 s,优化率 18.6%。研究可为商场应急管理和公共安全建设提供理论支持。     

A probabilistic approach for the analysis of evacuation movement data

This paper presents a probabilistic approach to analyse evacuation movement data. The approach relies on a detailed video analysis of people movement and pattern reconstruction. Conditional probabilities for travel path trajectories, walking speeds, and physical area occupied on stair landings are calculated for the evacuee population. The approach has been applied as a case study using data from an evacuation drill performed in a six-storey office building in the United States. The evacuation drill was filmed and occupant's behaviours on stairs were analysed using the new method. A comparison with the deterministic methods currently employed in engineering practice has been performed. The benefits of the probabilistic approach are discussed, including (1) a more accurate representation of people movement and (2) the use of probabilistic data for modelling purposes, i.e., model validation and model development.     

Influences of intelligent evacuation guidance system on crowd evacuation in building fire

The intelligent evacuation guidance system (IEGS) is a new concept and product in China, using an intelligent inducing algorithm to get dynamic evacuation routes and improving evacuation efficiency. This paper analyzes IEGS's influences on crowd evacuation by simulating a fire scene on the experimental platform of the “black house”, and some important conclusions are obtained. These conclusions including layout of exit position, settings of evacuation channel number and width, determining of installation distance and installation position mode of the intelligent acousto-optic evacuation indicator (IAEI), and choice of sound and visual inducing, can be a guidance in practical engineering and provide a reference for national standard ‘fire emergency evacuation lighting indication system (EELIS)’ modification.     

Effectiveness of downward evacuation in a large-scale subway fire using Fire Dynamics Simulator

Effective evacuation routes in the case of a large-scale subway fire were studied. A serious problem in the subway fire is that the directions of smoke flow are coincident with those of evacuation toward the surface. Hence, it is necessary to design an evacuation route without interference from smoke. A disastrous fire broke out in the Jungangno subway station in Daegu, South Korea in 2003. Based on this case, the Jungangno subway station with three basement levels was used in Fire Dynamics Simulator model in this study. The influences of smoke, temperature, and toxic gases (carbon monoxide [CO] and carbon dioxide [CO₂]) were computed at the evacuation staircases in the subway station with a fire source in the third basement floor (B3). The calculations showed that the evacuation staircases had high smoke density, temperature, and concentrations of CO and CO₂ in the subway fire. Hence, these factors greatly affected all of the upward evacuation staircases due to the coincidence of the smoke flow and the evacuation routes. Therefore, our paper proposes a new subway station with a fourth basement floor (B4) having downward evacuation routes which are in the opposite direction to the smoke flow. The results of analysis show that these factors hardly affected the staircases from B3 to B4. We conclude that downward evacuation can be more effective than upward evacuation for a large-scale subway fire.     

Simulation of high-rise building evacuation considering fatigue factor based on cellular automata: A case study in China

Stair evacuation plays a crucial role in building evacuation since stairs are generally the only means to evacuate high-rises on fire. To ensure safety stair design, the Life Safety Code suggests using a performance-based design approach, which requires evacuation simulations. Most of existing simulations, however, do not consider the structure of stairs and fatigue of evacuees, and these simulations are not validated by real emergency events or experiments. This paper is on improving the simulation of pedestrian flow in the stairs of high-rises by addressing these issues. A new Cellular Automata simulation model is developed where the simulation map is divided into zones based on the stair structure, and the rule of evacuees’ movement for each zone is appropriately defined to simulate turning behavior. To validate the simulation, a fire drill was held in two high-rise buildings. In this drill, evacuees felt tired after a walk. The simulation results demonstrate that, compared with the simulation without fatigue factor, our simulation can predict the evacuation time more accurately. Building designers can make evacuation plans and strategies based on the new simulation.     

Dynamic,Stream-Balancing,Turn-Minimizing,Accessible Wayfinding for Emergency Evacuation of People Who Use a Wheelchair

People with disabilities (PWD) cannot take all the routes accessible to people without disabilities because of their disabilities, attached equipment, lower speed, and larger space requirement. This results in more challenges and slower movements for PWD during emergency evacuations in comparison with people without disabilities. This study focuses on the accessibility of egress routes to people who use a wheelchair (PWW) during an emergency evacuation, referred to as egressibility. While this research benefits from the existing literature on indoor wayfinding for PWW, it considers three additional criteria to find the most convenient route for emergency evacuation of PWW: (a) avoiding blockages due to the collapse of walls or ceilings, (b) minimizing turns, and (c) balancing the congestion by offering less-congested routes in response to new requests. The results showed that considering turn minimization as an extra factor in finding the most accessible route could prevent the evacuees from changing the elevator or taking too many turns, just to avoid a slightly less convenient, yet accessible, segment. The results also showed the efficiency of the algorithm in returning the second optimal egress route to avoid blocked segments. The pedestrian congestion minimization component of the algorithm temporarily decreases a segment’s desirability to be included in other egress routes. The experiments showed the benefit of this component in offering an alternative optimal egress route to evacuees whenever it is more convenient than the more crowded first optimal egress route.     

基于声指示的疏散引导技术研究

为克服疏散指示标志仅依赖视觉信息的局限性,引入基于音频信息的声音导向技术,作为疏散指示标志的有效补充。介绍声音导向技术的工作原理,建立声音定位实验系统,开展实验研究,并分析声音导向装置与音频类报警设施的兼容性,测试声音导向疏散装置定位准确率。研究表明,声音导向装置可与音频报警装置同时工作,能够在紧急疏散时明显降低疏散时间,帮助人们快速找到正确的疏散通道及安全出口。     

How Do People with Disabilities Consider Fire Safety and Evacuation Possibilities in Historical Buildings?—A Swedish Case Study

An exploratory focus group study of people with different types of disabilities, e.g. mobility, visual and auditory, was carried out to explore how evacuation safety in historical buildings can be improved for people with various disabilities. Accounts of real life experiences on how well evacuation routes in historical buildings are adapted to people with different types of disabilities, as well as suggestions for safety enhancing measures, were collected. Some examples of reported problems were level differences on the way to and in evacuation routes for people with mobility impairments. Other examples were problems with orientation for people with visual disabilities and problems with detecting the evacuation alarm signal for people with auditory disabilities. In general the participants expressed different problems and needs depending on their type of disability. A common view amongst all the participants were that organizational parameters concerning evacuation of people with disabilities have to be improved. One conclusion from the study was that there are shortcomings in the physical environment as well as in the organization of evacuation in historical buildings today. This means that emergency evacuation safety must be properly focused on when improving accessibility in historical buildings. Measures must be taken to address the different needs of people with various types of disabilities as well as to make improvements for all user groups.     

基于BIM与Revit的地下建筑火灾预警及疏散系统

为预防地铁等地下建筑火灾事故,将BIM与Revit技术应用于地下建筑火灾预警和疏散管理中,分析不同条件下烟雾、人员疏散过程变化,实现对地铁火灾的预警和疏散可视化平台建设。以某运营地铁站为例,根据火灾烟气扩散过程确定烟气高度作为评价疏散安全性的指标,获得临界烟气最小高度下的可用疏散时间;通过人员量化处理进行人员疏散模拟,获得必需疏散时间并与可用疏散时间对比,进行建筑模型的评价和优化,以满足安全使用要求。结果表明：现有疏散通道布局存在一定安全隐患,可通过撤除不合理商业箱、提高候车公共区空地面积、增加喷淋设备密度、组织安全疏散演练等方式降低疏散时间,降低安全隐患。     

特长铁路隧道横通道间距设置问题研究

铁路隧道的横通道作为灾害发生后的安全疏散通道,其间距的设置在人员安全疏散中是至关重要的。本文以特长铁路隧道为研究对象,从人员安全疏散的角度出发,运用疏散模拟软件STEPS建立人员安全疏散计算数学模型,模拟计算了两种火灾场景在不同横通道间距情况下人员疏散所必需时间,通过与人员安全疏散可利用时间比较,判断人员疏散的安全性,给出了一般特长铁路隧道横通道间距设置方案,为特长铁路隧道安全疏散设施的优化设计提供理论依据。     

基于FDS+EVAC的应急演练过程人员疏散数值模拟

应用FDS+EVAC结合中庭式建筑工程算例,计算得出建筑物空间发生火灾后的空气流速、烟气运动、温度场等情况,通过Smokeview展示火灾的动态发展过程;针对人员安全疏散相关控制指标进行讨论,着重分析应急演练过程中人员疏散的可能性和有效性,发现演练过程中人员疏散可能出现的问题。探讨基于人员疏散计算机数值模拟技术科学合理组织和规划消防应急演练的技术方法。     

Location optimization algorithm for emergency signs in public facilities and its application to a single-floor supermarket

Although emergency signs are believed to play an important role in ensuring public safety in facilities during emergencies, in practice, specific and clear standards for placing emergency signs have not yet been established. This paper developed a heuristic algorithm based on the Lagrangian relaxation algorithm for optimizing emergency sign locations with consideration of light-occlusion effects. A cellular automaton (CA) evacuation model was then introduced, and based on this model, the evacuation efficiency of the optimized locations of emergency signs derived from the algorithm was verified, and was compared with the evacuation efficiencies of the same supermarket without and with existing emergency signs. The results showed that the proposed algorithm greatly enlarged the coverage of emergency signs and improved the evacuation efficiency. It was concluded that the proposed algorithm with consideration of light-occlusion effects is valid for application to the problem of location optimization of emergency signs in single-floor facilities.     

Sequencing and combining participation in urban planning: The case of tsunami-ravaged Onagawa Town,Japan

Onagawa, a remote rural town in Japan, is on the verge of crisis: its population is aging and shrinking, and this adversity has been even more pronounced since the town was ravaged by the 2011 Great East Japan Earthquake and resulting tsunami. In its struggle to survive and revive, the town has emerged as a gem of participatory governance by instituting a multitude of participatory mechanisms with renewed leadership. This development shows how disasters induced by natural hazards can be a catalyst for progressive democratic change in a rural town like Onagawa, in contrast with earlier findings that disasters adversely affect democratic institutions and values. Onagawa's case also draws scholarly and policy attention to how to sequence and combine different participatory mechanisms in urban planning. Informed by field work, the study modifies an existing theoretical model to systematically highlight Onagawa's participatory mechanisms during the reconstruction planning, including their differences and complementarities. This institutional plurality served multiple purposes, including (i) allowing lay stakeholders to brainstorm a general reconstruction plan, (ii) avoiding the conflation of technical and lay discussions, (iii) reaching out to evacuees who were not able to participate, and (iv) educating citizens on town planning in hopes of nourishing a participatory culture in the long run.     

人员疏散动力学模型

建立人员疏散动力学模型,认为人群的移动速度取决于位于人群前面和后面的人的移动速度,以及行人本身想要移动的积极性。于2011年春节期间在杭州火车站进行了一个关于拥挤人群疏散的研究,研究表明拥挤人群的最大人员密度和每个人最快的移动速度分别是2.75人/m2和1.54 m/s。在此基础上合理化人员疏散动力学模型,并进行敏感性分析。     

某会议中心人员疏散性能化设计

针对某会议中心主会议厅消防设计存在防火分区面积超过规范规定、人员疏散距离超长的问题,运用性能化设计方法分析,并提出设置"准安全区"以解决人员疏散问题。针对主会议厅设计4个火灾场景,并分别进行疏散模拟。分析结果表明,将共享大厅作为"准安全区"的疏散设计方案,可以帮助解决主会议厅疏散距离过长的问题,实现人员安全疏散。     

Staircase evacuation modeling and its comparison with an egress drill

We study an evacuation process of a four-story building by means of an egress drill and simulations. The evacuation in the staircase is much different from that in flat areas in the building because of some special characteristics, for example, the twisting and descending passageway; the interflow of crowds at the joint of staircase and hallway; the turning behavior at the turning point between two flights. Considering the characteristics of human behavior and staircase structure, we develop an improved multi-grid model for the staircase evacuation. For a finer discretization of space, the key size of structures and boundaries are figured more accurately, and what is more, the rectangular body size, various walking speed in different densities, turning behavior of pedestrians are taken into account in the model. It is found that the interflow between the new entrance students from the hallway and students from upper staircase leads to a congestion in the buffer area which slows down the crowd speed. This area is just the bottleneck of the staircase evacuation. The simulation results are compared with the egress drill data, and there is close agreement between them. It implies that the composed model is reasonable and can be used to quantify staircase egress behaviors.