An analysis of evacuation travel paths on stair landings by means of conditional probabilities

This paper analyses data on occupants׳ movement on stair landings collected during an evacuation drill performed in a six-storey office building in the United States. A total of 215 occupant travel path trajectories were filmed and time on the stair landings and egress behaviours were analysed. Data were analysed using a probabilistic approach, i.e., the probability of different occupant travel paths were calculated in relation to two different factors: (1) crowding on the landings, and (2) the type of interactions between occupants (e.g., merging flows, deference/overtaking behaviours, etc.). Results showed that a higher number of occupants on stair landings caused an increase in the probability for (1) longer travel paths and (2) usage of the outer boundaries on the stair/landing connections. This paper highlights that data and modelling assumptions should be used after a careful evaluation of their field of applicability. In the case of a low occupant load and non-homogenous merging streams (a higher number of people entering the landing from the stairs than the door), floors tend to be emptied from the top to the bottom.     

大型商场人员疏散安全通道的评估体系研究

从通道形态、通道防火分隔、通道烟控能力、疏散能力与建筑性价比5个方面,基于层次分析和模糊综合评价的方法,建立大型商场人员疏散安全通道的评估体系。基于该评估体系,以沈阳某商场为例进行实例分析,结果表明,该体系可分析出适合该商场实际特点的安全通道方案。     

孤立森林算法的灭火救援疏散路径规划方法

针对建筑火灾中人员疏散路径规划问题,提出基于孤立森林算法的灭火救援疏散路径规划的方法。运用布置在火灾现场的无线传感器网络采集火灾环境信息,构建火灾数据样本,随机分割并训练火灾数据样本,创建多个孤立二叉树组建孤立森林,识别火灾异常数据,获得着火点及障碍物位置,并以栅格法构建火灾救援环境动态地图为基础,通过更新位置节点当量距离、信息素浓度以及信息素挥发因子的改进蚁群算法,构建救援疏散路径组合优化模型,规划出最佳灭火救援疏散路径。测试结果表明：该方法可准确检测火灾中的着火点位置,可在多起点、多终点的救援疏散路径规划中更好地避开着火点和障碍物,快速、合理地规划出最佳灭火救援疏散路径。     

面向多约束的室内消防路径查询方法研究

对消防疏散路径规划问题的研究通常是仅考虑路径最短这一条件,较少考虑多约束条件对路径查询的影响,给消防疏散带来了一定的局限性.本文将基于多种约束条件,即融合距离约束、消防设施数量约束、危险区域数量约束,进行室内消防路径查询方法研究.通过BIM技术对室内混合路网数据以及消防信息进行提取,搭建出消防综合路网数据;再通过设计函...     

某大型芯片生产厂房防火分区的性能化设计

针对某芯片生产厂房由于生产工艺要求，防火分区和安全疏散距离不能满足规范要求的问题，通过性能化分析方法对该设计能否保证内部人员安全疏散进行了评估，得出安全性分析，并在消防系统设置、日常管理及安全疏散方面提出建议。     

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。     

Evacuation performance of individuals in different visibility conditions

Accurate data on evacuation activities are required under visually handicapped conditions to increase the certainty of the fire performance-based designs and evacuation calculation models. This study was to analyze human behavior characteristics and evacuation performance change through the experiments under evacuation environment where smoke influences visibility. The evacuation experiment was conducted in four different visibility conditions at underground facilities with 125 subjects. The individual evacuation activities of the subjects regarding the evacuation time, movement speed, way-finding and the evacuation routes were recorded and studied. Difference in visibility condition caused changes in evacuee’s movement speed and travel distance. The change in visibility condition by indoor ordinary lights caused significant change only in movement speed on flat floors. However, the change in visibility by smoke caused significant change in travel distance as well as movement speed. These changes in evacuation performance were different, depending on the spatial characteristic.     

Fire Evacuation in Underground Transportation Systems: A Review of Accidents and Empirical Research

Previous fire accidents have shown that fires in underground transportation systems, e.g., tunnels and underground stations, can cause many fatalities. It is therefore important in fire safety design to give adequate consideration to all aspects related to evacuation. The main purpose of this paper is to provide guidance to engineers involved in the design of underground transportation systems, and to create a basis for future research in the area. A review of previously reported fire accidents and of empirical research is performed. The review of accidents is based on a theoretical framework, namely four accepted human behaviour theories, which can be used in the fire safety design of underground transportation systems. Factors important for fire evacuation in these types of facilities are also presented, and data related to these factors are summarised. The review reveals many potential solutions to commonly observed evacuation problems, but it also shows that there is room for further future research in the area.     

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.     

Social influence during the initial phase of a fire evacuation—Analysis of evacuation experiments in a cinema theatre

Unannounced evacuation experiments in a cinema theatre were analysed. The analysis focused on investigating if people are influenced by others during the initial phase of a fire evacuation. This type of influence is called social influence. Three separate behaviour types were identified and studied and the recognition and pre-movement time was measured. The results suggest that social influence is an important factor and that it becomes more important when the fire cue, e.g., the alarm, is unclear or uninformative. Results also indicate that social influence increases with decreasing distance between visitors. This result implies that individuals are influenced more by people who are close than by people who are further away.     

Development of a Risk Assessment Method for Life Safety in Case of Fire in Rail Tunnels

The present paper describes the development of a risk assessment methodology to quantify the life safety risk for people present in a rail tunnel in the context of the creation of a fire safety design. A bow-tie structure represents the risk assessment model, starting from major contributing factors leading to disastrous events. Using past accidents for the construction of the event tree part of the bow-tie, the most important factors are determined to be: human behaviour; fire growth; ventilation conditions; safety system (e.g. Smoke & Heat Exhaust, detection, voice communication, etc.); population density. These factors are incorporated into the event tree using pathway factors. Frequencies are calculated for each branch outcome based on data from research projects, fault tree analysis and engineering judgement. For the determination of the consequences, the method makes use of three integrated models: the smoke spread, the evacuation and the consequence model. The models can take into account all types of geometry and materials, human behaviour and different susceptibilities of people for smoke. Together, they determine the possible number of fatalities, by means of an FID (Fractional Incapacitation Dose) value, in case of a fire in a rail tunnel. The final risk is presented by the expected number of fatalities, the individual risk and the societal risk. The societal risk is demonstrated by means of an FN-curve (Frequency/Number of Casualty-curve).     

低照度下火场应急疏散标志颜色特征研究

为研究低照度火灾场景中应急疏散标志的颜色特征变化,提出了一种基于闵氏距离的低照度颜色特征量化方法,利用统计学方法研究低照度下火场标志背景的颜色特征参数。首先分别在室内灯光环境和低照度单一火场环境中取得标志背景的图片样本;其次对试验图片进行检测统计、特征提取;最后统计并分析图像的闵氏距离、方差。试验结果表明：近火场标志背景使用效果变差,绿色和蓝色背景标志尤为明显。以非接触测量的闵氏距离方法能够有效度量各通道值,并能分析各参数对结果影响的大小。     

某大型商业综合体消防性能化分析

以某大型商业综合体建筑为例,分析其消防安全存在的问题如:防火分区面积过大、人员疏散距离过长、四层影厅面积不符合消防规范等,提出性能化解决方案如:室内步行街作为临时安全区、两侧店铺设置“喷淋十钢化玻璃”与步行街分隔、调整疏散出口宽度等,并利用FDS和Pathfinder进行消防性能化评估,验证方案可行,前提是必须保证各消防设施的有效动作,结果可为同类建筑商业综合体提供参考依据.     

慢行道隧道火灾疏散门间距设置研究

隧道内慢行道发生火灾,机动车行道作为疏散通道时,在现有规范中,未对疏散门间距给出明确要求。以济南春暄路隧道为工程实例,慢行道火灾情况下对比必需疏散时间与可用疏散时间,验证其疏散安全性以及疏散门间距有效性。结果表明,慢行道发生火灾,耐火极限2 h的中隔墙和甲级防火门将慢行道与机动车道分隔成两个防火分区,机动车道可作为安全区;火源前后均有疏散人员,且人员无法绕过火源疏散,为防止通风时烟气向另一侧聚集危害人员安全,故不进行通风排烟,烟气自由蔓延;疏散门间距为250 m、火源正对疏散门时,不满足人员安全疏散要求;疏散门间距为200 m和150 m时,满足人员安全疏散要求。从安全和运行成本综合考虑,推荐慢行道内疏散门设置间距为200 m。     

CFD simulation and assessment of life safety in a subway train fire

Fire is a major risk in the event of subway train fire due to coincidence with direction of smoke flow and evacuation. As a part of an effort to improve the life safety in a train fire, the platform screen door (PSD) is more and more installed on the ground that PSD provides a lot of benefits to passenger’s safety. Therefore, the investigation of effect of PSD on life safety is needed. In this study, fire simulation and evacuation simulation are performed to estimate the effect of PSD and ventilation on passenger’s life safety in a subway train fire. The Fire Dynamics Simulator (FDS V406) code is used to predict smoke spread and the available safe egress time during the fire. The evacuation of a subway station due to a train fire is simulated to predict the time required for evacuation, obtaining travel speed as a function of density. The passengers in platform with PSD and ventilation system have much more available time of about 350 s than passengers in case without PSD and ventilation system in modeled subway station. The subway turnstiles (ticket gate) dramatically increase the time required for evacuation without moving toward exits and bring passenger’s life safety danger in a subway train fire.     

民宿建筑特殊防火设计研究

摘 要：村镇建筑一般存在防火间距小、耐火等级低等问题,目前越来越多的村镇自建住宅被改为民宿等对外经营场所,功能改变之后,带来了疏散相对困难、火灾荷载增加等问题,导致其火灾风险进一步变大。将特殊防火设计方法应用于村镇建筑,以某典型村镇民宿建筑为例进行特殊防火设计,采用理论计算和数值模拟方式进行了人员疏散安全性分析、火灾蔓延安全性分析和结构安全性分析,给出了增设火灾自动报警装置、设置自闭门、安装甲级防火窗、增设不燃吊顶等解决策略,降低了建筑火灾风险,提高了消防安全性,为特殊防火设计方法在村镇建筑中的应用提供参考。     

某商场安全疏散的性能化设计分析

本研究根据商场的建筑结构特点、功能要求、人员状况和消防设施情况,确定了保证人员安全疏散的安全目标。运用调查类比、理论分析和数值模拟等手段,依据国内外建筑防火规范、火灾科学的研究成果和施工图,针对商场的可燃物特性设定了火灾场景,进行了火灾过程模拟与人员疏散模拟研究。在设定的条件下,人员疏散是安全的。经过性能化防火设计与评估后,提高了商场的经济效益与社会效益,也体现了性能化方法的科学性、安全性与经济性。     

建筑火灾中人员疏散响应过程推理与评估模型研究

为了预防建筑火灾发生和减少火灾中人员的伤亡,利用消防大数据分析技术和贝叶斯网络分析方法,研究了建筑火灾发展过程及人员疏散响应过程的推理与动态评估方法。通过对建筑消防设施响应状态和火灾中人员心理和行为特征的分析,探讨了火灾阶段划分方法和人员疏散行为的分类,提出了火灾中人员伤亡的轨迹交叉理论,进而构建了基于贝叶斯网络的建筑火灾动态风险和人员疏散安全评估框架。分别探讨了建筑火灾发展、人员疏散响应等2 条研究主线的推理过程,探讨了疏散条件评估过程。研究表明,该模型可通过对建筑特征、消防设施状态信息以及人员响应信息等消防大数据进行融合,实现火灾中人员疏散响应过程推理与动态风险评估,从而提高建筑消防安全管理水平