EXPERIMENT OF SMOKE-PREVENTING AIR CURTAINS IN HIGH-RISE BUILDING FIRES

In high-rise building fires, the most immediate threat to passenger life and safety evacuation is the smoke inhalation. Some traditional models for smoke prevention and exhaust are analyzed and compared with the smoke-preventing air curtain. The rationality and the feasibility of the air curtain are theoretically expounded. The air volume, tuyere width and jet velocity in the air curtain experiment are designed according to the theoreti- cal calculation model. Experimental results indicate that the effect of air curtain to prevent smoke diffusion is re- markable as the volume ratio of air-smoke is about 0. 6, the jet angle is between 25^o and 35^o, and the jet thickness is between 25 mm and 45 mm. The efficiency of air curtain can reach 98% on the entraining effect. Meanwhile, experiments verify the theorectical calculation.

A review on research of fire dynamics in high-rise buildings

Since serious fire occurred frequently in recent years, fire safety of high-rise building has attracted extensive attention. A National Basic Research Program （973 program） of China has been set up by Ministry of Science and Technology （MOST） of China in 2012 to meet the research requirements of fire safety in high-rise buildings. This paper reviews the current state of art of research on fire dynamics of high-rise buildings, including the up-to-date progress of this project. The following three subjects on fire dynamics of high-rise buildings are addressed in this review： the ejected flame and fire plume behavior over facade out of the compartment window, the flame spread behavior over facade thermal insulation materiMs, and the buoyancy-driven smoke transportation characteristics along long vertical channels in high-rise buildings. Prospective future works are discussed and summarized.

基于FireNet的古建筑火灾检测方法研究及改进

针对古建筑火灾检测需要快速、准确及实时的需求,建立了一个专门用于古建筑火灾检测的数据集,用于古建筑火灾检测的深度学习研究。利用CBAM注意力机制模块,结合多尺度特征融合,对FireNet网络进行改进,提出适用于古建筑火灾检测的轻量级FireNet-AMF网络,在FireNet数据集和本文构建的古建筑火灾检测数据集上验证了FireNet-AMF网络的火灾检测能力。与改进前的网络相比,FireNet-AMF网络在FireNet数据集上对火灾识别的准确率达到了95.08%,与原网络相比提高了1.17%,在本文构建的古建筑火灾检测数据集上的准确率达到了95.62%,比原网络提高了1.62%。该网络在保证轻量级的同时也保证了在古建筑火灾检测中较高的检测精度。

Urban Spatial Risk Assessment of Fire from Fueling Stations on Buildings Case Study: Lubaga Division, Kampala City, Uganda

The discovery of oil and gas in Uganda has attracted many investors, leading to increase in fuel/gas distributing companies and fueling stations creating rapid demand for land to locate the stations compared to available open urban land. Because of the explosive and combustion characteristics of fuel stored and dispensed at stations, several studies have been conducted on different fires at fueling stations such as static fire, jet fire, vapor cloud explosions, open fires, etc. but there was need to assess spatially the risk of fire from stations, its consequences and sovereignty on buildings surrounding them. This was done basing on seven parameters—proximity of buildings to stations, building materials, distance between buildings, wind speed, temperature, slope and vegetation. Analytical hierarchy process and pairwise comparison were used to weight the parameters based on their relative importance. Weighted sum tool was applied to generate the fire risk maps for the quarters—December to February, March to May, June to August, and September to November from 2008 to 2013. The parameters were overlaid with the buildings in each risk zone for all the four quarters and their influences determined. The highest contributors were proximity of the buildings to stations, building materials and separation between buildings. Most of the affected buildings were made of rusted corrugated iron sheets and wood;the separation distance from one building to another ranged from 0 - 4 m. Most of buildings located within 100 m from stations were at moderate risk level and within 50 m were at highest risk level. The period of December to February and June to August had the highest risk. The findings can be used to guide planners and policy makers on building location vs. material vs. separation. It can also guide developers on where, when and how to carry out their developments.

High-rise building fire pre-warning model based on the support vector regression

Aiming at reducing the deficiency of the traditional fire pre-warning algorithms and the intelligent fire pre-warning algorithms such as artificial neural network,and then to improve the accuracy of fire prewarning for high-rise buildings,a composite fire pre-warning controller is designed according to the characteristic（ nonlinear,less historical data,many influence factors）,also a high-rise building fire pre-warning model is set up based on the support vector regression（ SV R）. Then the wood fire standard history data is applied to make empirical analysis. The research results can provide a reliable decision support framework for high-rise building fire pre-warning.

基于Building EXODUS的地铁站疏散仿真模拟及优化设计

运用疏散模拟软件Building EXODUS,对地铁站实际项目进行火灾安全疏散模拟,研究地铁站疏散时间、疏散者行为、疏散路线及各个关键节点的通行能力等问题。根据模拟结果和数据优化地铁站流线组织和建筑布局,大大缩短地铁站安全疏散时间,提高其服务水平和安全性。研究结果表明:火灾情况下的安全疏散应考虑疏散者心理及火灾产生的影响,合理布置楼梯、闸机等可提高疏散效率,引导设施(如栏杆等)的设置可优化疏散路线,避免关键节点拥堵对安全疏散产生负面影响。

Fire risk of green building technical components

The concept of the green building as sustainable construction has continuously been studied,developed and distributed.Technologies to realize the green building to use less energy,while protecting the environment and improving the quality of residences have increasingly been used in not only new buildings in the design phase,but also in existing ones to reduce the energy and environment loads.Therefore,the number of green buildings is increasing.However,there are some cases that green building technologies for low energy use,low carbon emissions and pleasant indoor environment violate fire safety standards;so it is imminent to address the issue.Furthermore,unlike continuous studies on development and distribution of green buildings,there are few studies on the issue because of the lack of fire safety awareness of green buildings.Therefore,this study intends to raise the awareness of fire safety awareness of green buildings through theoretical consideration and analysis of cases about green building technologies.

Autoclaved Aerated Concrete Block Prefabricated Multi-Storey Building Technology

In active response to the national requirements of promoting green building materials and developing prefabricated buildings,it is necessary to continuously optimize and reasonably employ relevant technologies.Autoclaved aerated concrete block prefabricated multi-storey building technology is a new technology,which will not only effectively realize green environmental protection in construction engineering,but also promote the further development of prefabricated buildings.Therefore,this paper analyzes the autoclaved aerated concrete block prefabricated multi-storey building technology for future references.

Investigation on Fire Protection System of Highrise Buildings in the Context of Bir Uttam Aminul Haque Avenue in Dhaka, Bangladesh

Rapid high-rise building construction of different occupancies is becoming popular in Dhaka due to its economic gain and functional flexibility. Fire prevention poses a significant difficulty to this type of construction due to its complexity and economic worth as well. Therefore, construction of high-rise building without following the proper fire safety measures, is a common practice at present in the city and it poses a greater threat to urban life considering its associated loss. Even though, most of the owners or authorities do not respect the construction code and the majority of them lack sufficient awareness and basic fire control knowledge and practice. More often, they are unable to comprehend the magnitude and severity of severe fire hazards, and recognize the causes and implementing effective mitigation measures are rare. As a result, the number of fire hazard in high-rise construction is increasing day by day. Hence, investigating the present condition of high-rise buildings (already built) in terms of Fire Protection System is imperative to prevent the upcoming fire hazard. An urban chunk of 33 plots along with Bir Uttam Aminul Haque Avenue, located in Banani, has been chosen for the study area considering its vulnerability to fire hazard. Among these buildings, STAR Tower and HBR Tower, these two high-rise buildings are assessed thoroughly using FRI (Fire Risk Index) Method. The method is semi-quantitative in nature with seventeen parameters associated with fire protection. This assessment represents a scenario in what extent fire codes are being followed in the selected area. It concludes that most of the buildings lack in providing protection against fire hazards for not following the code strictly. This research provides some recommendations which can be followed to improve the fire safety measures in this existing context. It is expected that this research could be a unique addition to firefighting knowledge by contributing to mitigating the consequences of fire related hazards in any densely populated city like Dhaka.

Review of Conventional and Innovative Technologies for Fire Retrofitting of Existing Buildings

Fire effects can be one of the most harmful conditions that any building may experience throughout its service life. Developing practical protection methods and concepts against potential fire disasters in buildings has been an important consideration in design of buildings in recent decades. Rapid developments in technology have heightened the demand for new and innovative fire protection systems in comparison with conventional and traditional methods. Such a need for new technologies is in particular of greater importance when it comes to existing buildings. Retrofitting an existing building for fire safety is a greater challenge compared with designing a new building using materials and components that have more desirable and superior fire rating to begin with. Furthermore, strategies to design a new building that includes state-of-the-art fire safety features are also different from solutions that may be more suitable for retrofitting an existing building. This paper presents a review of the literature concerning conventional and new or innovative retrofitting methods for fire safety of buildings. Advantages and disadvantages of different fire protection devices and methods as available and understood from the literature are mentioned. Study of fire safety systems shows that each has its drawbacks. Comparison of the results shows that disadvantages of a solitary system for retrofitting against fire can be improved by using a combination of several fire safety concepts or methods simultaneously.

Dynamic Responses Analysis of a Building Structure Subjected to Ground Shock from a Tunnel Explosion

Dynamic responses of a multi-storey building without or with a sliding base-isolation device for ground shock induced by an in-tunnel explosion are numerically analyzed. The effect of an adjacent tunnel in between the building and the explosion tunnel, which affects ground shock propagation , is considered in the analysis. Different modeling methods, such as the eight-node equal-parametric finite element and mass-lumped system, are used to establish the coupling model consisting of the two adjacent tunnels, the surrounding soil medium with the Lysmer viscous boundary condition, and the multi-storey building with or without the sliding base-isolation device. In numerical calculations , a continuous friction model, which is different from the traditional Coulomb friction model, is adopted to improve the computational efficiency and reduce the accumulated errors. Some example analyses are subsequently performed to study the response characteristics of the building and the sliding base-isolation device to ground shock. The effect of the adjacent tunnel in between the building and the explosion tunnel on the ground shock wave propagation is also investigated. The final conclusions based on the numerical results will provide some guidance in engineering practice.

超高层建筑综合体消防负荷供配电系统设计

结合现行国家、行业及地方规范、标准,对超高层建筑综合体的消防负荷供配电系统、柴油发电机选择等设计方法及设计要点进行详细探讨。

老旧教学楼火灾场景人员疏散仿真研究

为提高老旧教学楼火灾场景下人员应急疏散能力,建立一个老旧教学楼火灾人员疏散模型。运用PyroSim软件建立火灾扩散模型,模拟分析该教学楼在机械排烟、自动喷淋和着火房间窗户是否开启的情况下,发生火灾时着火楼层安全出口处的烟气能见度、温度和CO的变化规律;结合Pathfinder软件对出口状态、人员疏散进行模拟仿真,得到人员全部疏散完成时所需安全疏散时间。实验结果表明:老旧教学楼无喷淋时人员疏散效率降低12.1%,无机械排烟时人员疏散处于危险状态,多设出口对提升人员疏散效率影响较小。

夹芯镀锌钢板复合墙板对木结构建筑外部火灾蔓延的延缓与阻断作用研究

目的提出一种新型夹芯镀锌钢板复合墙板,以延缓与阻断村镇木结构建筑的外部火灾蔓延。方法采用火灾环境模拟软件PyroSim建立西南地区穿斗式木结构建筑数值模型,从发生火灾后的室外温度和外部火灾蔓延时间的角度,对比分析复合墙板对外部火灾蔓延的延缓与阻断效果及其合理布设方式。结果综合考虑地形、地势以及大气环境等不确定因素的影响,建议西南地区穿斗式木结构建筑防火间距取值为6.0 m以上。对于封堵山墙通风洞口的木结构建筑而言,当前后立面方向的建筑间距为3.0 m时,复合墙板的布设能够将火灾蔓延至相邻建筑物的时间延长约60 s;当前后立面方向的建筑间距为4.0 m时,复合墙板的布设将有效阻断外部火灾蔓延。结论对于未封堵山墙通风洞口的木结构建筑物而言,应以合理设置防火间距作为控制外部火灾蔓延的手段。对于封堵山墙通风洞口的木结构建筑物而言,在前后立面外墙布设复合墙板,既能延缓外部火灾蔓延,又能有效降低成本。

森林环境文物建筑集中区域灭火救援能力评估

针对森林环境文物建筑集中区域环境复杂,难以准确评估区域灭火救援能力等问题,基于层次分析法(AHP),提出耦合森林因素的单体文物建筑灭火救援能力评估方法,涵盖建筑材料、森林防火隔离带、消防水源等19个二级指标;在单体评估基础上,从区域视角建立一种基于变权法的森林环境文物建筑集中区域灭火救援能力评估模型;并引入惩罚占主导的混合型变权函数,设置评价策略,确定惩罚与激励区间,区分文物建筑保护等级,提出风险等级划分方法;通过实地调研和数据收集,结合定权法和变权法评价森林环境文物建筑集中区域(岳麓山风景名胜区)的灭火救援能力。结果表明:单体文物建筑评级为优、良、中、次、差的数量占比分别为12%、20%、32%、20%、16%。区域定权法得分为75.27(Ⅲ级,不需采取提升措施),变权法得分为69.97(Ⅳ级,需采取提升措施);建议采取增设电气火灾预警系统、增加森林防火隔离带等措施来提升灭火救援能力。

燃煤电力工程建构筑物结构安全鉴定的若干要点分析

该文分析了燃煤电力工程建构筑物的结构安全鉴定要点,强调了随着生产力提高,结构安全性的重要性。尽管燃煤电力企业的建构筑物面临耐久性和结构安全问题,但定期检测尚未形成制度性文件。文章指出,燃煤电厂的复杂结构和恶劣环境导致许多建构筑物存在锈蚀、变形等隐患,且日常维护工作往往依赖经验,缺乏专业性。为确保安全,建议在工艺提升前进行可靠性鉴定,并每3~5年进行一次结构安全性鉴定。通过案例分析,展示了锅炉钢架的鉴定过程,强调了对结构构件的全面检测和分析,确保其承载力符合标准。最后,提出了定期检查和监测的建议,以降低安全风险,保障企业的安全生产。

基于事故树的高层建筑火灾分析及预防研究

为明确高层建筑火灾致因因素,通过运用事故树理论来分析高层建筑火灾。首先,根据事故树理论方法构建事故树,在构建事故树过程中对寻找到的基础事件进行因素分类,将其分为个人因素和组织因素;其次,通过对事故树中的逻辑关系进行布尔代数运算,找出最小割集和最小径集,通过计算出的最小割集和最小径集进行结构重要度计算,以确定在其模型结构中的重要程度;最后,将重要程度与其因素种类进行对应,找出在火灾中造成更大影响的因素种类,并结合实例进行分析。结果表明,事故树方法可以准确找出高层建筑火灾中造成更大影响的因素种类并得出科学有效的预防措施,为高层建筑火灾的安全管理和事故预防提供新的分析思路和参考。

高层建筑消防安全隐患及对策分析

随着我国城市化进程的加速,高层建筑数量不断增加,具有安全隐患多、火灾蔓延快、灭火困难等特点。如果发生火灾,极易造成巨大的财产损失和人员伤亡。从火灾发生、发展、灭火和救援4个方面总结了高层建筑的火灾特点,基于事故“4M”要素理论将高层建筑存在的消防安全隐患分为内部人员隐患、硬件设施隐患和安全管理隐患,并根据上述隐患进行分析,提出了提高高层建筑内部人员消防安全意识、严格执行高层建筑消防防火设计标准规范、明确消防安全管理责任主体、严格实施高层建筑消防日常监督管理和审核验收、构建基于物联网的高层建筑消防安全管理一体化平台等对策,从而提升消防安全管理的信息化水平。

基于数字孪生的多层建筑火灾应急系统研究

智慧型灭火技术对于确保高楼安全至关重要。提出了一种新的多层建筑火灾应急系统。该系统利用数字孪生模块来获取建筑物的几何尺寸和位置信息,此外还可以监测室内烟雾浓度和温度。如果发生火灾,该系统可以立即向消防部门报告,并且可以根据情况动态调整逃生时间和路径。运用了Revit和PyroSim以及Pathfinder软件模拟多层建筑火灾发生的情况,对烟气浓度和扩散速率进行了模拟分析,以此合理安排人员逃生路径。结果表明:研究不仅可以提升多层建筑灭火的效率,还可以确保能够在消防人员抵达火场之前根据系统提供的信息制定出有效的灭火计划,从而更加精确地预测可能发生的情况,以此保障生命财产安全。

高校实验楼火灾应急疏散模拟仿真

为研究高校实验楼发生火灾烟气扩散和人员应急疏散,以某高校实验楼为例,通过Revit软件建立BIM模型,导入Pyrosim软件进行火灾模拟仿真研究,分析在3种不同的火灾场景下,烟气的蔓延以及能见度、CO浓度和烟气温度的变化情况。同时利用Pathfinder软件进行人员疏散模拟仿真研究,分析了各关键疏散口的拥堵情况,并计算出安全疏散时间以评估各个疏散口的安全性。提出优化方案引导人员进行有效地疏散,并对比引导前后的疏散时间。结果表明:能见度是影响人员疏散时间的最主要因素,由于实验楼走廊狭窄,在火灾发生时,烟气会迅速蔓延至楼梯间影响人员疏散;走廊尽头及拐角处的CO浓度会更高;启用楼外楼梯时会大幅降低整体疏散时间;引导人员进行有效疏散后,疏散总用时减小25.5 s,所有楼层关键疏散口在不同火灾场景下均达到安全标准。