浅谈建筑防火分隔

防火分隔是指在建筑物内部或两座相邻建筑物之间为阻止火灾蔓延扩大、减少火灾损失、为火灾扑救争取时间而采取的防火隔断措施，一般是采用具有一定耐火强度的防火分隔物把建筑内部空间分隔成若干较小的防火分区，一旦某一分区内发生火灾，可以有效地阻止火灾在建筑物的水平方向和垂直方向扩展，而在一定时间内将火势控制在一定区域内。当前，建筑工程中常用的防火分隔物主要有防火墙、防火门、窗和防火卷帘等。为了保证建筑防火分隔能发挥作用，建筑设计和施工人员在进行建筑工程设计和施工时，应注意解决好以下几点：一、应按照国家《建筑…     

已有建筑物防火安全评估分级标准及方法研究

随着我国经济的发展,建筑物火灾问题日益突出,一旦发生火灾将生成经济损失和人员伤亡,而减少杜绝建筑火灾的发生,关键在于解决好建筑物的防火安全问题。如能对现有建筑物的火灾损失进行预测,对社会和经济将有重要的意义。主要探已有建筑物的防火安全评估的方法。     

35—110kV变电所火灾及对策

变电所。易发生火灾的设备主要有变压器、油开关、电缆等。消防的侧重点不是抢救设备本身，主要是防止扩散和蔓延，危及临近设备。变电所火灾对策主要是配置化学灭火器，所内电气设备之间，建筑物与设备之间要符合最小防火净距要求，电缆的防火主要是分隔和阻燃。     

芬兰赫尔辛基市的消防工作(下)

1、异常严格的建筑防火工作。 赫尔辛基市消防部门在多年实践中认识到,城市中的大部分火灾都是在建筑物中发生的,因此必须把搞好建筑防火列为消防工作的重点之一。全市各管区消防部门都有多名建筑防火工程师,其任务是专门监督和检查建筑物防火。凡是新建楼房的地方,他们都直接深入建筑工地,向建筑部门提出防火规定,监督检查防火措施的落实,凡是不符合防火规范的建筑必须改建。建筑防火工程师每年还要对管区内的建筑物进行防火检查,发现火灾隐患及时报告。发现重大火灾隐患和必须采取重大措施时,要及时报告内政部。     

试论建筑物防火监督的有效方法

对建筑物火灾现状进行研究,以建筑物防火监督的重要性为出发点,采用数据、案例分析的方式,对现阶段建筑物面临的主要火灾问题进行了深入的剖析,并提出提高建筑物防火监督的有效途径,达到有效改善现阶段建筑物防火监督存在的问题,提高防火监督工作效率和水平的目的。     

建筑结构的火灾分析和处理(一)——火灾温度确定方法

国内外许多工业与民用建筑物火灾实例说明,由于在设计上对防火技术措施未予考虑或考虑不够周密,一旦发生火灾,会造成严重的伤亡事故和经济损失,甚至带来极不良的政治影响。而在火灾发生后,未能通过科学的分析和鉴定,制定和采用先进合理的修复处理措施,这不仅会延误修复时间,影响生产,而且更严重的是使修复后的建筑物留下隐患,发生坍塌事故,造成经济损失。所以,在消防工作上,必须贯彻执行“预防为主,防消结合”的方针。不但要在建筑设计上采用先进合理的防火技术,而且对于火灾后的建筑物要积极采取技术先进、经济合理、安全适用、确保质量的修复处理措施。为此,本刊组织了“建筑结构的火灾分析和处理”的技术讲座,宣传和交流对于火灾后的建筑物进行科学的分析和鉴定方法,以及相应的修复和处理措施,供大家借鉴。     

基于文献角度分析高层建筑火灾致灾关键因素及防火对策研究

高层建筑在带动土地升值的同时也存在着很大的火灾隐患,而精准识别其火灾致灾关键因素并进行针对性预防能有效降低其火灾发生风险.鉴于此,本文基于文献计量思想并结合建筑、消防管理专家意见对高层建筑火灾致灾关键因素进行了识别,从建筑物主动防火能力、建筑物被动防火能力等六个维度构建出高层建筑火灾致灾关键因素体系并据此提出了防火建议...     

防火门自动控制设计与应用之我见

作为建筑物的水平防火分隔措施的主要防火分隔物——防火门．在防止火灾和烟气蔓延中超着关键作用。因此防火门在火灾时的闭合状态至关重要。对此，《高层民用建筑设计防火规范》、《火灾自动报警系统设计规范》均有明确的要求，如常开的防火门，当发生火灾时，应具有自行关闭和信号反馈的功能，     

35—110kV变电所火灾及对策

变电所。易发生火灾的设备主要有变压器、油开关、电缆等。消防的侧重点不是抢救设备本身,主要是防止扩散和蔓延,危及临近设备。变电所火灾对策主要是配置化学灭火器,所内电气设备之间,建筑物与设备之间要符合最小防火净距要求,电缆的防火主要是分隔和阻燃。     

火灾下钢结构楼板的薄膜作用

通过对真实火灾中的足尺火灾试验和观察显示，合组合楼板和承载钢梁的建筑物的结构承载力比现行杭大设计方法的建议值高出许多。因此规范中规定所有承载钢梁都要添加被动防火保护是不必要的。现行设计方法和实际结构性能之间产生这种差异是由于设计方法中忽略了楼板的薄膜作用。本根据国外有关资料给出了几种简单计算方法，允许在钢结构杭大设计中考虑楼板的薄膜作用。从而可以更精确地评估火灾下建筑物的真实承载能力，在给定的耐火时间内能减少相当数量钢梁的防火保护。     

地下式污水处理厂大空间火灾实体模拟试验的研究

现行国家规范缺少对地下式污水处理厂建设的指导意见,水厂与普通工业建筑参照性较差,消防设计及验收方面存在较大困惑,导致各地区类似项目设计方式差异很大。因此,有必要对地下式污水处理厂火灾工况进行模拟试验,得到有针对性的相关数据,推导出可在项目设计中具有实际参考意义的结论,以利于制定相应的消防对策。     

Critical factors governing the fire performance of high strength concrete systems

High strength concrete (HSC), is being increasingly used in a number of building applications, where structural fire safety is one of the major design considerations. Many research studies clearly indicate that the fire performance of HSC is different from that of normal strength concrete (NSC) and that HSC may not exhibit same level of performance (as NSC) in fire. This paper discusses the material, structural and fire characteristics that influence the performance of HSC under fire conditions. Data from earlier experimental and numerical studies is used to illustrate the impact the concrete (material) mix design and structural detailing (design) has on fire performance of HSC systems. An understanding of various factors influencing fire performance will aid in developing appropriate solutions for mitigating spalling and enhancing fire resistance of HSC members.     

Experimental behaviour of composite slabs during the heating and cooling fire stages

Most theoretical and experimental research investigating the effect of fire on structures has previously concentrated only on the structural behaviour during the heating stages of the fire, partly due to the fact that internationally accepted standard fire tests only consider this stage of the fire. Evidence from real fires in real buildings has highlighted that the cooling phase of a fire is equally important and it is possible for structures to fail during this stage of the fire even though they have survived the heating stage up to a maximum fire temperature. This paper provides an insight into the behaviour of composite slabs under different fire scenarios considering both the heating and cooling phase of the fire. Extensive test data is presented which shows the redistribution of moments and strains in the deck and steel mesh, together with displacements during the full duration of the fire. The results show that the behaviour of composite slabs is dependent on the heating rate, the maximum temperature reached and the cooling rate. In terms of overall performance, displacements and the temperature on the non-fire side of the slab are important. For the tests presented in this paper it was shown that one fire scenario resulted in the maximum displacement but another fire scenario resulted in the maximum temperature on the unexposed face. In addition the maximum temperature of the unexposed side of the slab and the mesh reinforcement within the slab occurring during the cooling stages of the fire. This highlights the fact that the performance of structures must be checked in design under a range of possible fire scenarios, which must include both the heating and cooling stages of a fire.     

Enclosure smoke filling revisited

Building fires go through a series of stages. They start with a fire plume/ceiling jet period during which buoyant fire gases rise to the ceiling and spread radially beneath the ceiling. A second stage, the enclosure smoke-filling period, follows; this second stage is the subject of this paper. It has been more than 20 yr since Zukoski first addressed the smoke filling stage of enclosure fires in terms of thermodynamic control volume concepts and fire plume entrainment, yet his analysis remains pertinent. This paper reviews and extends fire modeling concepts related to enclosure smoke filling developed by Zukoski. The mass-based analysis of Zukoski is recast in terms of the volumetric flow rates typically used for ventilation system design; it is extended to consider global average temperature rise and the effects of oxygen consumption on the maximum global average temperature rise that can be achieved in a closed-room fire. A spreadsheet template is developed to compare hand calculations based on a global analysis with numerical smoke filling calculations. Results of this comparison suggest that there is little difference in conditions predicted with the global hand calculations and the numerical smoke filling calculations; consequently, the hand calculations are suitable for preliminary fire hazard analyses.     

蔓延火灾下钢框架结构抗火性能试验研究

为研究蔓延火灾下钢框架结构建筑室内火灾温度场、钢构件温度分布和位移的发展规律,对1个足尺的两层钢框架结构进行蔓延火灾试验,测量试验区域内关键位置的空气温度、钢构件温度和位移。试验结果表明：试验中火源房间内的火灾过程呈现4个明显的发展阶段,受火70min时室内火灾达到全盛,测得火灾烟气层最高温度730℃;受火82min时火灾从火源房间蔓延至邻近房间,导致了邻近房间内各受火钢构件温度峰值出现在不同时刻,同时,各构件历经扩散热烟气加热、直接受火加热和冷却降温3个阶段,呈现反复升降温的受火过程;受火过程中,钢构件温度变化显著滞后于火场温度,受火钢柱先后升温产生向上的轴向变形。与传统室内火灾相比,蔓延火灾扩大了火场范围和钢结构受火范围,对结构安全和人员安全造成更大威胁,因此在进行结构抗火设计时应得到充分考虑。     

Fire Induced Spalling in High Strength Concrete Beams

A macroscopic finite element model is extended to account for fire induced spalling in high strength concrete (HSC) beams. The model is based on the principles of mechanics and thermodynamics and utilizes pore pressure calculations to predict fire induced spalling in concrete. For validating the model, spalling measurements were made by conducting fire resistance experiments on four normal strength and high strength concrete beams. Spalling predictions from the model are compared with the measured values of spalling at various stages of fire exposure. The validated model is applied to investigate the influence of fire scenario, concrete strength (permeability) and axial restraint on the fire induced spalling and fire response of RC beams. Results from the analysis show that fire scenario, and concrete permeability largely influence the extent of fire induced spalling in concrete beams. Further, it is also shown that the extent of spalling has significant influence on the fire resistance of RC beams.     

Structural performance of a post-tensioned concrete floor during horizontally travelling fires

This paper highlights the structural performance of a bonded post-tensioned concrete floor subject to fires that travel horizontally between zones within the floorplate. The floorplate was previously analysed by the authors based on experimental and numerical investigations on one-way spanning bonded post-tensioned concrete slab strips. In the previous studies, a nonlinear finite element model was developed for the floor that considered the mechanical and thermal material nonlinearities of the floor’s components, interfaces between the components, different natural fire severities, different applied static load during the fire and different restraint conditions. The previous studies highlighted the importance of investigating the whole-building behaviour and provided a useful insight into the temperature distribution throughout the floor slab, failure modes, comparisons with current design rules and time-displacement behaviour of the floor under fire conditions. This paper extends the previous studies and uses the validated finite element model to investigate different horizontal travelling fire scenarios between zones and different inter-zone time delays to represent fire travelling time. The time-temperature distribution throughout the floor slab was predicted at different locations in the floor subject to travelling fires. Furthermore, the time-deflection and time-axial displacement relationships were predicted at different locations in the floor. The current study has shown that horizontally travelling fire scenarios and the inter-zone time delay affect the time-deflection behaviour considerably. The change in heating/cooling scenarios between zones has resulted in a cyclic deflection pattern, which has previously not been considered when designing post-tensioned concrete floors against fire. Based on the analysis of the results presented, it is shown that the worst case in terms of maximum vertical defection or maximum residual deflection, at a given point in the floorplate, could occur either under the assumption of a uniform fire or a travelling fire. It is therefore recommended that designers should consider the integrity of floorplates using various travelling fires.     

A numerical approach for modeling the fire induced restraint effects in reinforced concrete beams

In this paper, a model to predict the influence of fire induced restraints on the fire resistance of reinforced concrete (RC) beams is presented. The three stages, associated with the fire growth, thermal and structural analysis, for the calculation of fire resistance of the RC beams are explained. A simplified approach to account for spalling under fire conditions is incorporated into the model. The validity of the numerical model is established by comparing the predictions from the computer program with results from full-scale fire resistance tests. The program is used to conduct two case studies to investigate the influence of both the rotational and the axial restraint on the fire response of the RC beams. Through these case studies, it is shown that the restraint, both rotational and axial, has significant influence on the fire resistance of the RC beams.     

真实火灾下足尺冷成型钢复合剪力墙结构耐火性能试验研究

冷成型钢复合剪力墙结构采用冷成型钢管混凝土边柱、半刚性连接节点、组合楼盖体系和外填充式夹心组合墙体等构件,具有整体连接性强、抗震性能优越等优势。其耐火性能研究是该结构在我国推广应用的研究重点之一。为此,建造了3栋平面尺寸为7.2m×7.2m、层高3m的单层冷成型钢复合剪力墙结构模型房屋,并对其进行了不同火灾工况下的足尺结构模拟真实火灾试验。对试验现象、结构破坏模式、实际温度场和位移场进行分析。研究结果表明：相对于火源均匀分布的受火工况,存在局部集中火源的工况更容易发生轰燃;自然火灾下的小空间升温曲线对应温度改变可分为3个阶段,在封闭燃烧阶段和回燃阶段,受火房间内温度沿高度方向呈现不均匀分布,轰燃后,整个室内空间温度趋于相同;外填充式夹心组合墙体具有优越的耐火性能,自然火灾下耐火时间可以达到119min。针对冷成型钢复合剪力墙结构提出抗火设计建议：墙体应选用外填充式夹心组合墙体;楼盖体系中,应选用与钢材连接可靠的耐火板材作为天花板,楼面ALC板材应当错落放置;需增强楼面钢托梁与墙体上部双拼梁(框架梁)连接处的防火保护。