The quantitative investigation on people's pre-evacuation behavior under fire

With the growth in urbanization process and activities in Hong Kong and many large cities in China, a great number of super high-rise buildings have been constructed in these years. The occurrences of many large fire tragedies, especially the US 9/11 terrorist attack, made people aware that super high-rise buildings may cause serious fatalities, and extremely they could collapse in a huge uncontrolled fire. Compared with people's evacuation behavior, little interests have been drawn to pre-movement behavior. In Hong Kong and some major cities in China, over 90% of people are living in multi-storey multi-compartment buildings. Their awareness and responses to fire incidents happening in the other parts of the same building have substantial influence on the whole evacuation process. Studies on pre-evacuation human behavior have been performed for many years, but the vast majority of the studies were qualitative-oriented. Accordingly, an attempt was made in this article to quantitatively investigate people's pre-evacuation behavior by using the Support Vector Machine (SVM) approach, which was trained by Hong Kong's post-fire field survey data.     

Inherent fire consequence estimation tool (IFCET) for preliminary design of process plant

Fire hazard has contributed to about one-third of world major accidents in chemical plants. One of the approaches to avoid or minimize fire hazard is by using an inherent safety concept. This concept is best implemented at the preliminary design stage. However, practical application of inherent safety is still limited due to non-availability of easy to use tool for direct application in a process plant. This paper addresses the above issue by proposing a prototype tool known as Inherent Fire Consequence Estimation Tool (IFCET) that can be used during preliminary design stage to eliminate or minimize the consequence of fire accidents. The tool is developed in MS Excel for pool fire model and linked with process design simulator, iCON. The functionality of the IFCET is demonstrated using case studies of flammable liquid leaked from a process stream and spilled of LPG during unloading at filling station. The results from the case studies show that IFCET can be used to eliminate or minimize the consequence due to pool fire during preliminary design stage. IFCET has a potential to be extended to include other types of fire accidents such as Jet Fire, BLEVE, etc.     

Dynamic modeling of fire spread in building

Modeling fire spread in a building is a key factor of a fire risk analysis used for fire safety designs of large buildings. In this paper, a dynamic model of fire spread considering fire spread in both horizontal and vertical directions is described. The algorithms for simulating the fire spread process in buildings and calculating dynamic probability of fire spread for each compartment at each time step of simulation are proposed. The formulae used in calculating the input data for the dynamic fire spread model are derived. The dynamic fire spread model can easily be applied for any building including high-rise buildings. A detailed example of calculation of fire spread in a two-storey office building is described.     

大型商业建筑中庭火灾性能化分析研究

对各层中庭开口处未设置防火卷帘的大型商业建筑中庭火灾进行数值模拟,分析其火灾发展过程及烟气蔓延过程,研究该火灾场景下人员疏散的安全性。研究表明:火灾下,烟气通过各层中庭开口处向各楼层内蔓延,并对接近中庭顶部的楼层产生较大影响。但在本文的火灾场景下,人员均能安全疏散。大型商业建筑在各层中庭开口处不设置防火卷帘的设计方法在一定程度上仍然可以保证人员疏散的安全性。     

Building safety and human behaviour in fire: A literature review

The most crucial aspect of a building's safety in the face of fire is the possibility of safe escape. An important precondition is that its fire safety facilities enable independent and adequate fire response performances by the building's occupants. In practice, it appears that the measures currently required by law do not always provide the support that people in burning buildings need. Consequently, understanding how individuals behave in the case of fire and fire evacuation is essential if we are to bring fire safety measures into line with occupants’ needs during an incident. This paper contains a review of the available literature on human behaviour in a fire so far as building safety is concerned. The findings are presented as an overview of the critical factors which determine occupants’ fire response performances, namely the characteristics of fire, human beings and buildings. The study highlights that some of the assumptions about the existing paradigm of fire safety in buildings are not consistent with the knowledge set out in the literature. The key observation is that psychonomics appear to have significant influence on occupants’ fire response performances. Accordingly, the traditional approach to fire safety will have to be supplemented by scientific knowledge from this field. Hence, there is a need for a new approach to fire safety design in buildings, which is set out herein.     

基于计算机仿真模拟系统的奥运场馆火灾安全分析

本文以奥运场馆改造项目为背景,利用计算机技术,基于性能化防火分析的思想,采用自行开发的火灾安全模拟系统SFSAS,对体育场馆的火灾安全性能进行了综合分析。该系统采用数值模拟方法,将火灾场景模拟分析与结构分析综合为一体,模拟了北京奥运会将要使用的北航体育练习馆在设定火灾下的火灾场景和结构温度场的分布,分析了其屋面钢结构体系在火灾作用下的结构反应和力学性能。通过分析发现,在火灾影响下,原有结构体系的平衡被打破,火灾下的结构破坏表现为整体性的破坏,因而需要进行全面的整体分析,而不能仅仅考虑局部的影响。实例分析证明,本文介绍的火灾安全模拟系统功能强大,运行方便,充分体现了计算机仿真技术在建筑防火分析中的优越性。     

超大规模商业建筑防火设计的研究和实践

分析研究超大规模商业建筑的大空间的防火特征。本文从控制火灾荷载密度,扩宽疏散通道;使耐火分隔透明而通视,以提高大空间的方向识别性;防火分区以独立的商铺为单位;加强防排烟措施等方法提出防火设计的对策。并用于指导湖南株洲九天置业广场的工程设计实践。     

A probabilistic assessment for classification of bridges against fire hazard

This paper presents the development of a simplified approach for classification of bridges based on fire hazard. Statistical data from recent fires in bridges is utilized to quantify the probable risk of fire in bridges and also probability of fire-induced collapse of structural members in bridges. An importance factor is derived for identifying the vulnerability of bridges to fire hazard. The proposed importance factor, developed using weighted factor approach, takes into account the degree of vulnerability of different bridge components, critical nature of a bridge from traffic functionality point and fire mitigation strategies present in a specific bridge. The proposed importance factor for fire design, which is similar to the one currently used for evaluating wind, and snow loading in buildings, is validated against previous bridge fire incidents. It is shown through this validation that the proposed method for importance factor can be used as a practical tool for identifying critical bridges from the point of fire hazard.     

高层建筑火灾消防及安全逃生研究

高层建筑的火灾是威胁居民生命财产安全的重要因素,对高层建筑火灾进行深入的研究,能够降低火灾发生的可能性,并减少火灾带来的人身伤害和财产损失。本文分析了高层建筑发生火灾的原因,同时分析了高层建筑火灾的特点。高层建筑由于其建筑本身的高、人员密集以及室内空间较复杂等特点决定了发生火灾时危害性很大。本文之后给出了若身处高层建筑火灾中应采取的几点逃生策略,以便有效地降低人员的伤亡。最后,本文介绍了逃生模拟软件FDS+Evac,该软件可以有效地模拟火灾时室内温度场、烟流分布等情况,可以指导人员进行安全逃生。     

Assessment of fire reaction and fire resistance of Guadua angustifolia kunth bamboo

The main challenge for construction industry today is sustainability. Bamboo has properties that make it sustainable, but its fire behavior remains unknown. This paper presents an exploratory research on fire behavior of Guadua angustifolia kunth (a.k.) bamboo. Fire reaction was assessed through critical heat flux for ignition and flame spread while fire resistance through charring rate and strength variation with temperature. Fire reaction fall within standard limits used for structural woods, while fire resistance results are higher than that of plywood. Based on these preliminary results, Guadua a.k. would be adequate as structural and indoor finishing building material.     

The International FORUM of Fire Research Directors: A position paper on performance-based design for fire code applications

The International FORUM of Fire Research Directors (FORUM) periodically takes a position on a technical issue of international significance confronting the fire safety research community. The position of the FORUM on performance-based regulations, codes and design for fire safety applications, and the rationale leading to it, is described in this paper. Aspects addressed include current capabilities and challenges associated with the application of performance-based design, and possible enhancements (obtained through a coordinated and sustained global effort of research) in next generation tools leading to more certain predictions of the effects on performance of changes in building materials, active and passive fire protection systems, compartmentation, and egress systems; the structural response of a building to large fires including those leading to full building burnout; the impact of fire on neighboring buildings and infrastructure; and the uncertainty in deterministic predictions for incorporation into reliable probabilistic calculations of hazard and risk.     

钢屋盖结构防火的性能化消防工程分析

因为建筑学上和构造上的原因,越来越多的建筑设计采用了钢结构。为了保证建筑结构构件的完整性,建筑规范提出了结构耐火性能的要求。但是,已规定的要求没有促进具有良好经济效益的设计,并且假定遵照规范是达到安全等级的唯一途径。本论文提出采用以性能设计为基础的消防工程理论方法来证明火灾中钢构件的性能。消防工程准则已发展至符合规范的要求,并能保证结构在火灾中的安全性能。本文采用一个游泳/跳水馆作为例子来讨论对钢屋顶结构进行耐火保护。本例的研究表明,游泳/跳水馆的钢屋顶结构可以不用耐火涂料,并且不会降低整个建筑的防火安全等级。     

Numerical model and validation experiments of atrium enclosure fire in a new fire test facility

The use of computational fluid dynamics (CFD) as a tool for buildings, warehouses or factories design requirements fulfilling about fire safety is becoming more common and reliable. Performance-based fire safety assurance procedures make use of the CFD fire modelling to anticipate the evolution of fire, but they need always to be validated. This is especially difficult for big structures, with great clear volumes, where effects of natural and forced ventilation can be very scale dependent. A good opportunity to check the prediction capability of CFD codes to establish temperatures and velocities fields is the new full-scale fire test facility of the Technological Metal Centre in Murcia, Spain. It is an aluminium prismatic squared base building of 19.5 m×19.5 m×20 m, with several vents arranged in its walls and four exhaust fans at the roof. Series of experimental tests have been carried out using several heptane normalized pool-fires placed at the centre of the atrium. The data obtained from these experiments have been later used in a validation study of two CFD simulations implemented for temperature wall, ambient temperature prediction and exhaust fan assessment. The results show good agreement between experimental and numerical predictions and allow concluding that for a fire test of 1.6 MW of average heat release power, the exhaust and ventilation system is not enough to extract the hot combustion products. There is an excessive and dangerous accumulation of hot gases at the upper part of the atrium and the exhaust capacity of the roof fans must be increased. The CFD models can give the answer to that question.     

Reliability analysis of a glulam beam

The present case study is an example of the use of reliability analysis to asses the failure probability of a tapered glulam beam. This beam is part of a true structure built for a super market in the town of Kokemäki in Finland. The reliability analysis is carried out using the snow load statistics available from the site and on material strength information available from previous experiments. The Eurocode 5 and the Finnish building code are used as the deterministic methods to which the probabilistic method is compared to. The calculations show that the effect of the strength variation is not significant, when the coefficient of variation of the strength is around 15% as usually assumed for glulam. The probability of failure resulting from a deterministic design based on Eurocode 5 is low compared to the target values and lower sections are possible if applying a probabilistic design method. In fire design, if a 60 min resistance is required, this is not the case according to Eurocode 5 design procedures, a higher section would be required. However, a probabilistic based fire analysis results in bounds for the yearly probability of failure which are comparable to the target value and to the values obtained from the normal probabilistic based design.     

火灾自动报警系统设计中的几点个人见解

阐述火灾自动报警系统的构成,以及系统设计中涉及的几个基本理念;分析火灾发生、发展的基本过程及各阶段之间的关系;解释不同类型火灾探测器报警信号的含义;提出火灾确认与联动编程,以及切断发生火灾相关区域非消防电源的消防联动设计基本理念;给出了联动设计中联动设备的时序。