某底框架商住楼在火灾中倒塌原因数值分析

采用计算机数值模拟方法研究了某钢筋混凝土底框架商住楼柱子的耐火稳定性。结果表明 ,该建筑的下部商业用房中火灾荷载和上部实际作用的重力荷载均较大是该建筑物于火灾中倒塌的主要原因     

浅谈建筑结构的耐火设计

建筑结构是建筑工程中支承各种荷载作用的骨架,是建筑物赖以生存的基础。而在实际工作过程中,建筑结构的耐火设计则往往被人们所忽视,导致部分耐火程度不高的建筑物在火灾情况下的垮塌。1993年5月13日,南昌市万寿宫商城二区商住楼(9层建筑、高32.4m)火灾,由于使用了预应力钢筋混凝土楼板等不耐火构件,导致了该建筑大部分的倒塌。为此,建筑结构的耐火设计应当引起我们足够的重视。 一、火灾对建筑结构的破坏作用 建筑物发生火灾后,随着建筑构件的燃烧和破     

承重构件的耐火极限与荷载的关系

本文认为，承重构件试验中所加荷载越大，构件的耐火极限越小。为保证构件在火灾中安全可靠而不倒塌，建议《建筑构件耐火试验方法》第３．３．１条工作荷载应不小于设计荷载的７０％。     

我国建筑结构耐火设计综述

1建筑结构耐火设计的任务建筑结构耐火设计应包括以下两方面内容：（l）建筑物在给定火灾条件下（火灾荷载、通风条件、结构型式等）,其结构能否确保稳定而不失效倒塌;（2）如果评估结果将发生倒塌,采取什么技术措施予以避免。由此可见,建筑结构耐火设计的目的是防止?..     

浅谈多层商住楼火灾的扑救

论述了多层商住楼的建筑结构形式和火灾特点，在火灾环境中发生倒塌的原因、规律和判断方法，提出了扑救多层商住楼火灾的原则及要求。     

承重构件的耐火极限与荷载的关系

本文认为,承重构件试验中所加荷载越大,构件的耐火极限越小.为保证构件在火灾中安全可靠而不倒塌,建议《建筑构件耐火试验方法》第3.3.1条工作荷载应不小于设计荷载的70%.     

建筑结构在火灾条件下倒塌破坏的分析

随着经济的发展，高层建筑逐步增多，火灾荷载和不安全因素也随之增加。如果因火灾而造成高层建筑倒塌，必将给救人和救火带来更大的困难。据调查，美国“9·11”纽约世贸中心倒塌的原因在于大火熔化了支撑钢筋，而不是飞机的直接撞击，在爆炸现场救火的300多名消防人员及警察因建筑倒塌而丧生。 一、建筑结构倒塌原因 建筑物中建筑构件名目较多，近年来随着一些新材料、新工艺、新技术在建筑领域中的广泛应用，建筑构件的性能也变得越来越复杂，燃烧破坏的特点也趋于多样性。不同建筑构件均具有自身的燃烧性能和耐火极限。火灾条件下…     

某历史街区建筑火灾持续时间计算

建筑火灾持续时间与建筑的火灾荷栽、通风条件有关,是评价建筑物火灾损失和整体安全性的重要参数.结合 昆明某历史街区古建筑群,对建筑物的火灾荷载、通风条件进行了统计分析,在此基础上计算了建筑火灾持续时间的分布规律,进一步结合街区内建筑的耐火特性,分析了极端情况下火灾引起街区古建筑倒塌的概率.     

基于Android的底框架商住楼倒塌预测模型

以剩余强度作为商住楼底层承重柱承载能力的判定标准,结合基于标准升温曲线确定的三级温度曲线模型、统计得到的柱承载系数及分析温度应力与各影响因素,回归得到的经验公式,根据建筑结构基本原理构建了底框架商住楼倒塌预测模型,并编制了基于Android平台的商住楼倒塌预测软件。通过两个商住楼火灾倒塌案例的验证,软件的平均误差为7.2%。该软件可供灭火救援指挥员现场辅助决策使用。     

火灾下门式钢刚架倒塌预警可靠度研究

为了解决实际火灾救援中火灾场景、荷载水平等不确定因素对倒塌预警准确性的影响，基于可靠度理论提出了预测受火建筑倒塌剩余时间的方法。采用经试验验证的三维有限元模型对火灾下门式钢刚架结构倒塌进行仿真模拟，基于火灾下门式钢刚架结构四种倒塌模式和三级倒塌预警指标，研究升温工况、柱脚刚性、荷载比等因素对倒塌剩余时间预测的不定性影响，通过蒙特卡罗抽样，研究考虑各种影响的火灾下门式钢刚架倒塌预警指标概率统计参数。结果表明：倒塌剩余时间比仅与可靠度和倒塌模式有关，不受火灾现场的各种不确定性因素影响，可以在火灾发生前通过理论分析提前计算得到；火灾中采用可靠度60%～80%对应的倒塌剩余时间比可以快速合理地预测受火刚架的剩余倒塌时间。     

Development of realistic design fire time-temperature curves for the testing of cold-formed steel wall systems

Fire resistance rating of light gauge steel frame (LSF) wall systems is obtained from fire tests based on the standard fire time-temperature curve. However, fire severity has increased in modern buildings due to higher fuel loads as a result of modern furniture and light weight constructions that make use of thermoplastics materials, synthetic foams and fabrics. Some of these materials are high in calorific values and increase both the spread of fire growth and heat release rate, thus increasing the fire severity beyond that of the standard fire curve. Further, the standard fire curve does not include a decay phase that is present in natural fires. Despite the increasing usage of LSF walls, their behavior in real building fires is not fully understood. This paper presents the details of a research study aimed at developing realistic design fire curves for use in the fire tests of LSF walls. It includes a review of the characteristics of building fires, previously developed fire time-temperature curves, computer models and available parametric equations. The paper highlights that real building fire time-temperature curves depend on the fuel load representing the combustible building contents, ventilation openings and thermal properties of wall lining materials, and provides suitable values of many required parameters including fuel loads in residential buildings. Finally, realistic design fire time-temperature curves simulating the fire conditions in modern residential buildings are proposed for the testing of LSF walls.     

A probabilistic model of fire spread with time effects

The paper outlines the principal elements of a probabilistic model that analyses the spread of fire in multi-compartment buildings with respect to time. The analysis uses a graph theoretic network and an event hierarchy to determine the probability of fire spreading to different locations. The probability of fire spreading between compartments is based on a comparison of the probability density functions of the expected fire resistance and the fire severity: failure being the condition that severity exceeds resistance. The model is designed as a comparative tool to compare the performance of different fire safety strategies by calculating a ‘cost index’ for each design, based on the probable extent of fire damage in the building. The analysis gives attention to the compatibility of fire resistance and fire severity, and their conversion in real time parameters.     

浅谈钢结构抗火计算方法

对钢结构抗火设计的意义、建筑室内火灾的发展与温度变化进行了介绍，主要对钢结构在火灾条件下反应分析的有限元方法及其研究成果进行综述，并且指出了钢结构高温设计分析的发展方向。     

The fire situation and progress in fire safety science and technology in China

Since the 1950s, the direct property damage due to fire has increased with the development of industrialization and urbanization in China. The number of fire casualties has come down significantly since the 1980s while fire incidents with high casualties has occurred occasionally. Research on fire safety science and technology and its application have advanced, encouraged by Government at all levels, the Fire Service Department of the Ministry of Public Security and all of society. In recent years, the fire situation in China has become relatively stable and an effective strength in fire research has been established, comprising the four Fire Research Institutes of the Ministry of Public Security, the State Key Laboratory of Fire Science, fire enterprises and other fire research institutes. Since the 1990s, research has been carried out on fire detection and alarm, fire suppression techniques, structural fire-resistance, fire prevention techniques, fire modeling, performance-based fire protection design, urban fire protection planning, fire-fighting and rescue, fire protection standardization, fire dynamics and the fundamentals of fire protection. In the next 5 years, research will be focused on the theory of fire dynamics; evaluation techniques for fire risk and fire and rescue services of urban areas; new techniques of fire suppression systems and equipment and their engineering application; modernization of fire department apparatus and equipment; techniques for evaluation and design of structural fire resistance; human behavior in fire; development of a fire database; fire protection engineering economics; and performance-based fire protection design.     

Recent developments and applications in structural fire engineering design—A review

This review outlines some of the major developments that have occurred in structural fire engineering design during recent years.

The general principles used in fire engineering are discussed together with the various approaches that can be adopted by an architect or engineer to design a structure capable of withstanding the attack of fire without collapsing, using scientific concepts as a basis for determining the fire resistance and protection requirements. Details are provided of recent full-scale tests and research work either completed or in hand with the aim of producing design concepts and information which the fire engineer may use. Examples are discussed to show how structural fire engineering has been utilised in both large and small buildings to precisely define the fire resistance and protection requirements of steel frameworks. In some instances, estimates of the financial savings realised in following this type of approach are also given.     

性能化防火设计中人员疏散问题安全性的一种评估方法

提出了一种在性能化防火设计中人员疏散问题安全性的评估方法，该方法是把火灾烟气运动规律、建筑物结构和人员疏散特点结合的研究成果，分别计算建筑物中不同单元内的火灾荷载阚值，在发生火灾时，烟气达到危险状态的时间和人员疏散所用的时间，比较这两个时间来确定建筑物防火设计是否达到性能化防火中人员安全疏散的要求。该方法从控制建筑物内火灾荷载的多少和建筑物的结构出发，在现行的计算软件的基础上．可用于实际的火灾安全工程设计和火灾安全咨询。     

某鼓楼式高层酒店结构抗火与防火设计分析

以某鼓楼式高层建筑为例,针对其造型独特、外观新颖和民族特色鲜明的特点,以结构抗火和防火设计中存在的难点为切入点,在确保该建筑的结构抗火和建筑防火安全的前提下,依据国家有关规范、标准,基于结构可靠度和智慧防火理念,对其结构抗火材料、安全疏散、消防登高操作场地及消防设施设计的优化措施进行探讨。提出在设计类似鼓楼式的高层建筑时,应充分考虑火灾与风荷载等多灾种的耦合性,积极应用智慧消防等新技术,全面提升其结构可靠度和消防安全性。     

Performance-based analysis of large steel truss roof structure in fire

Due to the fast developments of large-space multi-functional architectures, large-span steel structures have been widely used in recent years. Therefore, the fire-resistance design of this kind of structures has attracted more attentions. Since traditional ISO834 standard fire curve is not suitable for large space structures, performance-based fire resistance design method is required. This paper presents the comprehensive case studies on the fire performance of a large space exhibition centre in Shanxi province, China under real fire scenarios including heating and cooling phases. The non-uniform fire temperature fields of the large space exhibition centre for the designed fire scenarios have been generated by using Fire Dynamic Simulator (FDS). A finite element (FE) model has been developed using FE software ANSYS for modelling the structural behaviour of the exhibition centre under different fire scenarios. Based on the results generated in this research some recommendations for the fire resistance design of large space steel truss structures have been proposed.     

不同受火方式下混凝土柱耐火性能的试验研究

通过5根高强混凝土柱和2根普通混凝土柱的足尺明火试验,考察了不同受火方式对混凝土柱破坏形态、轴向变形和耐火极限的影响。结果表明:(1)非四面受火柱的耐火极限较四面受火柱有很大提高,同时三面受火柱的耐火极限小于两面受火柱;(2)相同受火方式和相同轴压比下高强混凝土柱的耐火极限远低于普通混凝土柱;(3)相同受火方式下大轴压比普通混凝土柱的耐火极限可能小于中等轴压比的高强混凝土柱。在实际结构的抗火设计中,合理考虑受火方式、混凝土强度等级和轴压比的影响是十分必要的。