多楼梯建筑火灾烟气蔓延与人员疏散研究

利用Pyro-Sim软件建立多楼梯办公大楼3D模型,设置4个着火点,从温度、能见度、CO体积分数方面分析烟气在走廊和楼梯间的蔓延过程,得到不同工况、不同位置的危险临界时间。将模拟所得数据绘制成曲线图,结合Pathfinder软件进行人员疏散的研究。结果表明:对于楼梯为主要疏散通道的建筑,烟气先向通风口的方向蔓延,在楼梯间上下流动过程中向两边走廊扩散;能见度对人员疏散的影响大于温度和CO体积分数。     

三维疏散仿真平台CDS的构建及功能验证

基于正方形网格元胞自动机模型,开发了三维疏散仿真平台CDS.该软件通过读取AutoCAD图纸建立建筑模型并提供简便的楼梯建模方法.软件考虑了人员密度和疏散距离对人员行走速度的影响;通过设置不同的出口类型,考虑人员对建筑的熟悉程度及出口选择策略.模型验证表明,CDS平台计算精度高,能满足疏散仿真的工程需求.     

封闭楼梯间及防烟楼梯间中防火门的设置

封闭楼梯间和防烟楼梯间,是高层建筑、地下建筑和大体量建筑的最重要的安全疏散设施。作者通过几年来在消防监督工作中的经验,发现了现行规范中所要求的封闭楼梯间及防烟楼梯间的设置要求在应用时存在一些问题,由此对建筑中封闭楼梯间及防烟楼梯间的设置形式提出了自己的思考。     

某影院疏散出口优化分析

以位于高层建筑五层的某影院为例,应用EVACNET4,模拟建筑内人员疏散情况.该影院分两个防火分区,共5个放映厅,5部疏散楼梯. EVACNET4将人群走动模拟为水管网内的水流动.按三种设计方案进行模拟.即方案Ⅰ按原结构,方案Ⅱ改变放映厅出口布置,方案Ⅲ增加2部楼梯的宽度.结果:①改变放映厅出口布置不影响整个影院的疏散总时间;②人员堵塞主要发生在前室和楼梯间;③增加楼梯宽度有利于人员安全疏散.建议:在设计时,前室通向楼梯的门的宽度需大于楼梯的宽度.     

高层商店建筑的安全疏散设计

结合消防监督管理工作实际,分析了高层商店建筑安全出口宽度与疏散距离的关系,对高层商住楼底部商业营业厅不同疏散楼梯间形式的设置标准和高层建筑地下商店安全疏散设计的注意事项进行了探讨。     

超高层建筑楼梯与避难层不同设计对人员疏散的影响

通过分析火灾时人员的行为规律,运用疏散模拟软件对楼梯在进入避难层时设计成为强制进入避难区或不需强制进入避难区两种工况进行了对比分析研究。分析结果表明,如果楼梯设计为强制进入避难区的形式,这样的设计形式虽然整体疏散时间影响不大,但是可以减少避难区上部楼层人员疏散进入安全楼梯的时间和减少楼梯间内人员的拥堵,保证了疏散更加安全、有效。     

关于建筑安全疏散设计若干问题的讨论

分析了建筑物疏散宽度计算、疏散楼梯间设计等方面存在的问题.针对以下问题进行了研究:商业建筑、娱乐场所、展览厅等建筑疏散宽度计算;建筑物疏散楼梯间的分布、设计形式、多层建筑剪刀楼梯间或叠合楼梯设计等.提出建筑安全疏散设计应力求路线简捷易于辨认,符合人们的行为惯性,以提高建筑安全疏散设计的合理性和可靠性.     

剪刀楼梯应用于大型批发市场疏散的探讨

结合某市编制大型专业批发市场消防技术规范的需求,针对批发市场采用剪刀楼梯用于人员疏散的情况,采用人员疏散模拟分析软件设计典型大型专业批发市场人员疏散场景,分析采用剪刀楼梯对于人员疏散安全性的影响。研究结果表明,剪刀楼梯的疏散宽度、疏散距离是影响人员安全疏散的重要因素,均匀分布的剪刀楼梯对人员安全疏散效率的影响较小,过长的疏散距离会大大降低疏散效率。     

城市地下商业街火灾中逃生模型的分析

分析了地下商业街火灾时火灾临界危险条件和人员的疏散特点,提出了地下商业街火灾中人员安全疏散模型,确定了人员安全疏散时间的计算方法.以某地下商业街为例,计算了人员安全疏散所需要的时间,找出了人员能安全疏散的临界密度.研究与计算结果表明:该商业街火灾时,人员密度达到0.5人/m2后,楼梯口及楼梯间出现堵塞现象,人员开始出现混乱;同时,人员疏散至安全地带的楼梯总宽度是整个疏散过程的瓶颈,人员通过楼梯的时间占总疏散时间的80%以上,而楼梯的疏散能力主要受人员流量和楼梯的有效宽度所制约.基于计算结果,提出了相应的解决方法和措施.     

浅析楼梯的规范性设计与实际使用的安全性之间矛盾

楼梯是建筑中垂直交通设施,主要负责人流疏散,因此楼梯的合理设计对于正常使用以及突发情况的发生有着至关重要的作用,现行的楼梯设计做法在使用中经常出现不舒适,疏散时过分拥挤等情况,尤其在教学楼的楼梯中非常常见.打破传统的经验做法,进行楼梯间分层设计,调整不同楼梯间的形式,都是值得尝试的.当然需要大量的模拟疏散实验来确定楼梯新方案的可操作性.文章主要讨论教学楼疏散楼梯在使用时出现的问题,提出一些新的设计思路.     

高层写字楼火灾混合疏散策略研究

选取某高层写字楼进行实例研究,利用PyroSim进行火灾模拟,计算25层走廊着火时的可用安全疏散时间,运用Pathfinder建立人员紧急疏散模型,分析混合疏散策略对疏散效率的影响。结果表明：相比温度、CO体积分数,能见度到达人员安全疏散界限的时间更短。25层走廊着火时,最不利条件下着火层可用安全疏散时间为319.1 s。楼梯疏散、楼梯电梯混合疏散所需安全疏散时间分别为526.3、427.9 s,均不满足安全疏散条件。楼梯、电梯及避难层混合疏散所需安全疏散时间为294.2 s。楼梯、楼梯电梯混合疏散整栋楼分别用时2 618、2 289 s。楼梯、电梯与避难层混合疏散整栋楼用时1 796 s。因此,高层建筑火灾时,楼梯、电梯与避难层混合疏散效率更高,更安全。研究结果为制定高层写字楼火灾应急疏散预案提供依据。     

高层建筑电梯楼梯协同疏散的仿真实验研究

近年来高层建筑逐渐增多,但高层建筑普遍存在逃生线路长,火灾严重性大的问题。为了缩短高层建筑在消防疏散中的疏散时间,降低高层建筑火灾发生后的事故严重程度,利用疏散软件Pathfinder分析了高层建筑中使用电梯楼梯协同疏散的可行性。结果表明:高层建筑电梯可以作为协同疏散的辅助工具,增加一部电梯比单纯增加电梯最大运行速度要更加有效;设置每层电梯都使用总人数的固定比例进行疏散的时候,楼梯资源不易被充分利用;当设置n层及n层以上每层总人数的不同比例使用电梯进行向下疏散,存在最佳疏散楼层N11及最佳疏散比例20%,最后一个通过电梯疏散完毕与最后一个通过楼梯疏散完毕的人员仅相差2.7s,此方法可以为相关高层建筑火灾疏散策略的决策提供一定的参考依据。实验结果说明了电梯疏散的教育和培训很重要,在高层建筑中合理使用电梯进行疏散可以很大程度减少总疏散时长。     

Simulation of high-rise building evacuation considering fatigue factor based on cellular automata: A case study in China

Stair evacuation plays a crucial role in building evacuation since stairs are generally the only means to evacuate high-rises on fire. To ensure safety stair design, the Life Safety Code suggests using a performance-based design approach, which requires evacuation simulations. Most of existing simulations, however, do not consider the structure of stairs and fatigue of evacuees, and these simulations are not validated by real emergency events or experiments. This paper is on improving the simulation of pedestrian flow in the stairs of high-rises by addressing these issues. A new Cellular Automata simulation model is developed where the simulation map is divided into zones based on the stair structure, and the rule of evacuees’ movement for each zone is appropriately defined to simulate turning behavior. To validate the simulation, a fire drill was held in two high-rise buildings. In this drill, evacuees felt tired after a walk. The simulation results demonstrate that, compared with the simulation without fatigue factor, our simulation can predict the evacuation time more accurately. Building designers can make evacuation plans and strategies based on the new simulation.     

A pedestrian merging flow model for stair evacuation

Pedestrian merging flows on stairs are defined as the confluence of a flow of pedestrians from a stair and pedestrians from each floor of a multi-storey building. This paper introduces a novel simplified mathematical model for the calculation of evacuation times on stairs which takes into account the impact of merging flows. The model allows calculating the impact of merging ratio (people accessing the stair landing from the floor and from the stair) on pedestrian flows and evacuation times at each floor in congested situations. The assumptions and implementation of the model are presented. A hypothetical model case study of a 10-floor building evacuation is investigated, where the results of the new model are compared with the results of an evacuation simulation model using SimTread. Advantages and limitations of the new model in relation to the existing methods adopted for the simulation of merging flows on stairs are discussed.     

避难层停留时间对超高层建筑人员疏散的影响

针对超高层建筑中人员不同年龄层次、特征、性别要求,在上海中心大厦人员疏散实验的基础上,通过记录人体在长距离楼梯疏散过程中体能、血压及心率的变化,与避难层停留时间作对比分析,研究不同特征人员适合的疏散方式,如通过楼梯疏散的层数,是直接疏散到底还是下行到避难层停留后继续下行等。一系列数据结果分析可以为超高层建筑人员疏散提供参考。     

大型商业综合体人员安全疏散策略研究

针对商业综合体中人员疏散的滞留问题，探究人员安全疏散策略的引导作用。采用静态合作博弈论方法，进行路径优化。对某商业综合体典型区域从防火分区、疏散走道和疏散楼梯三方面进行人员疏散仿真模拟，对比人员安全引导疏散与传统疏散，结果表明优化后人员的疏散效率有显著提升；人员安全疏散引导人员从多个疏散出口进行逃生，在缓解了人员滞留问题的同时提高了在复杂环境中疏散出口的利用效率；博弈论路径优化明确了人员可选择逃生路径的数量，提高人员疏散效率。     

People Choice Modelling for Evacuation of Tall Buildings

Modelling people behaviour during emergencies has become an essential issue in attempting to increase safety aspects in buildings. This paper evaluates people’s choice behaviour for evacuation of tall buildings. A Stated Preference (SP) questionnaire was designed to understand underlying factors behind people behaviour and predict the likelihood of selecting evacuation lifts as opposed to stairs. Various scenarios including six different navigational cases, three levels for the density of people on stairs, three different number of people in the lift lobby and three vertical positions for refuge floors were administrated to 566 participants. A mixed logit model approach was then used to investigate how those factors influence the occupant’s decision-making as well as to capture the heterogeneity of different preferences among people. Traditionally, lifts were not allowed to be used in case of emergency, but the results indicate that people would tend to choose evacuation lifts in situations when they are suggested as the main exit option, and situations when stairs are overcrowded. Thus, if people are navigated by dynamic signs to use evacuation lifts, the percentage of lift users could go approximately from 70% to 80% for refuge floors between 15 and 55, respectively. In contrast, in situations when people have to make a decision between using lifts or stairs to evacuate, stairwells with fewer people as well as overcrowded refuge floors could lead to a decision in favour of stairs. This study represents the first SP experiment combining people decisions, pre-event opinions and beliefs related to evacuation lifts and stairs to understand their route choices for evacuation from tall buildings. The findings of this study can be used in the development of behavioural models for evacuation simulations of tall buildings.     

楼梯及转向平台的人流疏散问题研究

以经典社会力模型为基础,考虑楼梯间行人的各种相互作用力,引入转向概率进行修正,研究人群在楼梯内疏散的运动行为。进一步考虑人流率与时间的关系,提出非匀速下行人运动疏散时间模型,并基于AnyLogic平台模拟仿真,验证了模型的合理性,得到楼梯内行人运动存在的瓶颈现象,并给出相应的措施,为建筑物楼梯的规划与应急疏散引导提供参考。     

黄河公轨合建隧道火灾人员疏散安全研究

以济南黄河公轨合建隧道为研究对象,分别对公路隧道和轨道交通发生火灾时,纵向疏散楼梯和横向疏散门的间距对人员疏散时间的影响进行分析,获得必需疏散时间。结果表明：疏散楼梯间距为60 m和75 m时,均满足安全疏散要求;轨道交通发生火灾,在通风有效情况下,人员可用安全疏散时间TASET为2 700 s;疏散门间距为150 m和300 m时,均满足安全疏散要求。从安全和运行成本考虑,推荐疏散楼梯间距设置为75 m、下层疏散门间距设置为300 m。     

Movement on Stairs During Building Evacuations

The time that it takes an occupant population to reach safety when descending a stairwell during building evacuations is typically estimated by measureable engineering variables such as stair geometry, speed, density, and pre-observation delay. In turn, engineering models of building evacuation use these variables to predict the performance of egress systems for building design, emergency planning, or event reconstruction. As part of a program to better understand occupant movement and behavior during building emergencies, the Engineering Laboratory at the National Institute of Standards and Technology has collected stair movement data during fire drill evacuations of office and residential buildings. These data collections are intended to provide a better understanding of this principal building egress feature and develop a technical foundation for future codes and standards requirements. Fire drill evacuation data has been collected in 14 buildings (11 office buildings and 3 residential buildings) ranging from six to 62 stories in height that included a range of stair widths and occupant densities. A total of more than 22,000 individual measurements are included in the data set. This paper provides details of the data collected and an analysis of the data. The intention is to better understand movement during stairwell evacuations and provide data to test the predictive capability of building egress models. While mean and standard deviation of the distribution of movement speeds in the current study of 0.44 m/s ± 0.19 m/s are observed to be quite similar to the range of values in previous studies, mean local movement speeds as occupants traverse down the stairs are seen to vary widely within a given stairwell, ranging from 0.10 m/s ± 0.008 m/s to 1.7 m/s ± 0.13 m/s. These data provide confirmation of the adequacy of existing literature values typically used for occupant movement speeds and provide updated data for use in egress modeling or other engineering calculations.