楼梯位置对高校宿舍楼人员疏散安全性影响研究

选取某典型内廊式女生宿舍楼为研究实例,依据最不利原则设置4个典型火灾场景,利用PyroSim模拟火灾烟气运动过程,对烟气层高度、温度、能见度进行定量分析,得出各场景可用安全疏散时间;利用Pathfinder模拟火灾场景下人员疏散行动过程,得到必需安全疏散时间。结果表明,该宿舍楼各个楼梯承载人流量不均、个别楼梯拥堵瓶颈严重,人员疏散时间较长。调整一部楼梯位置优化人员疏散,着火层人员疏散时间缩短17.0 s,疏散安全性显著提高。     

高层建筑楼梯与电梯联合疏散模拟研究

运用Pathfinder 研究某高层建筑火灾人员安全疏散。首先模拟单楼梯、单电梯的单途径疏散，其次进行顶层优先疏散及避难层模式的楼梯-电梯联合疏散研究，并针对两种联合疏散策略采用不同人员分流的方法进一步优化。结果表明：在顶层优先疏散策略下，电梯最佳分离层会随每层人员数量的减少而下降；顶层优先疏散情况下人员分流优化后可以减少电梯空载的情况；避难层模式采用人员分流方法，可在不影响疏散效率的情况下根据实际情况合理分配中高部楼层乘坐电梯人员的比例。     

基于STEPS的超高层建筑人员疏散模拟研究

选取某超高层写字楼,使用STEPS软件进行人员疏散模拟。按照建筑设计容量和人员密度计算各楼层的人员荷载。将楼梯、不同分布高度的电梯、避难层三种疏散设施相组合,设置5种疏散方案进行模拟研究,得出不同方案下建筑内部剩余人数随时间变化的曲线以及不同方案中由电梯疏散的人数占总人数的百分比,分析各疏散方案的疏散效率。研究结果表明,"楼梯+电梯+避难层"的组合为最优疏散方案,疏散效率和安全性最高。     

高层建筑火灾中利用电梯疏散的可行性研究--广岛Motomachi高层公寓安全疏散案例研究

1.引言在发生建筑火灾时 ,居民一般应利用楼梯向室外或避难层疏散 ,而不是靠电梯疏散。然而 ,事实上在以往的许多火灾中 ,有不少人是利用电梯疏散的。如 1996年 10月 2 8日 ,日本广岛一栋 2 0层的高层公寓内发生火灾 (该公寓平面图及户型图分别如图 1、图 2 ) ,通过调查发现 ,在这次火灾中有一半以上的疏散人员就是利用电梯逃离火灾现场的。因此我们根据居住人员的特点 (如年龄大小 )、居住楼层的高度、火势以及烟气的扩散等问题 ,对利用电梯疏散的可能性进行了调查。另外 ,在日本和其它许多发达国家 ,随着人口老龄化程度的不断增加 ,无论是…     

避难层的消防设计

随着社会经济的发展,高层以上建筑不断增多,导致高层建筑发生火灾的因素也不断增多,扑救难度越来越大,因此,高层建筑应建立健全自防自救措施,确保人员的安全疏散和火灾自救。避难层是超高层建筑中专供发生火灾时人员临时避难使用的楼层。避难层在高层建筑发生火灾时对于人员的疏散逃生起到了举足轻重的作用,凡建筑高度超过１００ｍ的写字楼、旅馆、综合楼等均应设置避难层。避难层有全敞开式、半敞开式、封闭式三种类型。 全敞开式避难层不设围护结构,一般设在建筑物的顶层或屋顶上,这类避难层采用自然通风排烟方式,结构处理比较…     

地铁车厢火灾人员疏散安全性研究

分析了地铁车厢内火灾时人员疏散的全过程。采用Pathfinder2009.2软件计算得到车厢中部火灾和车厢端部火灾时人员所需安全疏散时间分别为65 s和139 s。采用FDS火灾模拟软件得到相应火灾场景下的危险来临时间(ASET)控制判断指标,结果表明,着火车厢内部人员能够安全疏散至非着火车厢。     

高层民用建筑避难层设计剖析

随着城市建设现代化程度的不断提高,城市中高层建筑逐渐增多。建筑高度超过100米的建筑,需要设置避难层。
　　避难层功能
　　高层建筑设置避难层,主要是供高层建筑发生火灾时人员临时避难使用。
　　高层民用建筑不但功能复杂、人员密集,而且机电设备众多,竖向管井也很多,一旦发生火灾,因烟囱效应、风效应,易产生火势迅速蔓延的情况,扑救困难。同时因为层数多,高度大,人员疏散距离远,所需疏散时间长。据统计,普通人在楼梯里连续下行5分钟后,就会感到体力不支。火灾发生时,楼梯间发生拥挤,人们会在等待排队的过程中耗费大量时间。建筑物层数越高,疏散所需的时间越长,疏散难度就越大,要将人员全部疏散至室外非常困难。因此,在高层建筑中间隔一定层数,设置避难区域,为人们提供休息避难,等待救援的场所。     

高层建筑火灾中消防电梯疏散效果模拟

分析通过消防电梯疏散人群的可行性,提出消防人员到达前、后两个阶段消防电梯辅助楼梯疏散的新模型,阐述运行规则,给出楼、电梯疏散的计算公式.根据电梯的运行规则,利用计算机模拟计算得到以下结论:消防人员到达前,消防电梯最佳停靠楼层的选择可通过计算得到,建筑的总层数和楼层人数愈多,电梯疏散人员比例越小;消防人员到达后,电梯在避难层停靠,通过计算得到避难层以上剩余人员以多少人员比选择消防电梯时,楼、电梯模型的疏散效率最佳.     

基于动力学的高层建筑竖直疏散效率分析

介绍楼梯疏散时间、电梯疏散时间的计算方法,利用动力学公式结合Origin软件,设定不同的疏散人数与楼层数,分析小规模群体低层疏散、大规模群体高层疏散以及楼梯电梯混合疏散。分析楼梯电梯混合疏散时待疏散群体规模对疏散效率的影响,提出待疏散群体规模的最优划分比例,并分析其影响因素,确定最优划分比例为40%。按照最优划分比例划分高层建筑物内待疏散群体规模进行楼梯电梯混合疏散,疏散时间短,效率高。     

基于BIM与Pathfinder的高层住宅应急疏散模拟研究

高层住宅人员应急疏散是一个复杂的过程。BIM技术通过数字信息仿真模拟建筑物所具有的真实信息。Pathfinder是一款基于火灾与紧急情况发生时人员疏散的模拟软件。建立了某高层10层住宅建筑的BIM模型,将BIM模型导入Pathfinder软件中,建立Pathfinder应急模型,进行该高层住宅的人员应急疏散研究。对于常规的采用全楼梯疏散模式,以实际情况即以楼梯为主电梯为辅的疏散模式进行对比研究。模拟结果表明,在一定层高下,以楼梯为主电梯为辅模式的疏散时间与全楼梯模式疏散时间相比更加省时。因此,在实际灾难逃生中,如果能够保证电梯的安全性,就能够大大提高高层住宅建筑逃生效率。     

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。     

Modelling total evacuation strategies for high-rise buildings

This paper focuses on the use of egress models to assess the optimal strategy in the case of total evacuation in high-rise buildings. The model case study consists of two identical twin towers linked with two sky-bridges at different heights. Each tower is a 50-floor office building. The use of either horizontal or vertical egress components or a combination of them is simulated. The egress components under consideration are stairs (either 2 or 3 stairs), occupant evacuation elevators, service elevators (available or not for the evacuation of the occupants), transfer floors and sky-bridges. Seven different evacuation strategies have been tested which consider the total evacuation of a single tower. The evacuation scenarios have been simulated with a continuous spatial representation evacuation model (Pathfinder). In order to perform a cross validation of the model results, two strategies involving the evacuation using stairs or occupant evacuation elevators have also been simulated using a fine network model (STEPS). Results refer to the analysis of total evacuation times. The simulation work highlights the assumptions required to represent the possible behaviours of the occupants in order to qualitatively rank the strategies. The lowest evacuation times are obtained simulating strategies involving the sole use of occupant evacuation elevators and the combined use of transfer floors and sky-bridges. This study suggests that the effectiveness of evacuation strategies involving the combination of stairs and elevators significantly decreases in high-rise buildings if they are not combined with appropriate messaging/signage to guide occupants in their behaviours.     

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。     

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 fire safety study of Hong Kong refuge floor building wall layout design

Since 1996, refuge floors have been an indispensable passive building element of the fire protection plan for Hong Kong high-rise buildings. These floors must be designed to comply with the relevant requirements of the Building Codes of Hong Kong. Hence, 50% of the floor area must be deployed for refuge purposes. And they must have at least two fully open building side walls so that a desired wind effect is assumed so that any smoke that enters will be purged from the safe area. Therefore wind-induced natural cross-ventilation is of prime importance for the protection of the refuge floor in fire safety. If this wind effect is not achieved, entering smoke will accumulate and cause the safety system to fail. Therefore fundamental studies of this flow phenomenon are very important and needed. This paper studies the wind-induced flow behaviour of Hong Kong's refuge floors. Different building wall layout designs are addressed. By way of this study, the author suggests that a refuge floor shall be designed to have two opposite building side walls open instead of the present Building Codes that require at least any two of them.     

A Study on People’s Attitude to the Use of Elevators for Fire Escape

Currently, elevators are not considered as a proper means of escape in fires and people have been educated and trained to use staircases for fire escape. However, it is difficult for all the occupants to evacuate only by staircases timely and safely in super high-rise buildings, especially for the old and disabled. Considering the fact that super high-rise buildings are constructed in increasing numbers in many Asian cities, it becomes much more necessary to reconsider the use of elevators for emergency escape. Besides a mechanically safe elevator system, people’s cooperation is of critical importance to assure an efficient egress process. To explore people’s attitude to the use of elevators for fire escape in high-rise buildings and the diversity based on demographics, a study was conducted via face-to-face interviews in two different cities of China. Respondents’ demographics and their responses to hypothetical fire scenarios were collected via a set of structured questions. The results showed that most people would consider using elevators for fire escape in super high-rise buildings. The main influencing factors of their attitude were firemen’s instruction and the height of their location in the building. Statistical diversity was found based on demographics. These results indicated that people’s attitude to elevator evacuation was positive and further study should be very important.     

Unannounced Evacuation Experiment in a High-Rise Hotel Building with Evacuation Elevators: A Study of Evacuation Behaviour Using Eye-Tracking

Past studies suggest that people are often reluctant to use occupant evacuation elevators in case of fire. However, existing research is scarce and current knowledge is based on questionnaire studies and laboratory experiments. An unannounced evacuation experiment was therefore performed on the 16th floor of a 35-floor high-rise hotel building. Sixty-seven participants took part and eye-tracking glasses were used to collect data on exit choice and eye fixations. Three different scenarios were studied, including two different hotel room locations on the floor and a variation of guidance system for one of these locations, i.e., flashing green lights next to the evacuation sign at the elevators. Results suggest that people typically choose the elevator for evacuation, even if their hotel room was located closer to the evacuation stair. Flashing green lights next to an evacuation sign made people look more at this sign. However, in spite of looking more at the sign, the flashing light was not shown to significantly improve compliance with the sign. Also, the results suggest that a detector activated self-closing fire door without vision panels to the elevator lobby made it more difficult to find the evacuation elevators in an emergency.

     

Comparison of FDS Prediction of Smoke Movement in a 10-Storey Building with Experimental Data

In this study, the Fire Dynamics Simulator (FDS), a computational fluid dynamics (CFD) model developed by National Institute of Standards and Technology (NIST) is used to simulate fire tests conducted at the National Research Council of Canada (CNRC). These tests were conducted in an experimental 10-storey tower to generate realistic smoke movement data. A full size FDS model of the tower was developed to predict smoke movement from fires that originate on the second floor. Three propane fire tests were modelled, and predictions of O₂, CO₂ concentrations and temperature on each floor are compared with the experimental data. This paper provides details of the tests, and the numerical modelling, and discusses the comparisons between the model results and the experiments. The 10-storey experimental tower was designed to simulate the centre core of high-rise buildings. It includes a compartment and corridor on each floor, a stair shaft, elevator shaft and service shafts. Three propane fire tests were conducted in 2006 and 2007 to study smoke movement through the stair shaft to the upper floors of the building. The fire was set in the compartment of the 2nd floor. Thermocouples and gas analyzers were placed on each floor to measure temperature and O₂, CO₂ and CO concentrations. Comparisons in the fire compartment and floor of fire show that the FDS model gives a good prediction of temperature and O₂ and CO₂ concentrations. In the stair shaft and upper floors there are some small differences which are due to the effect of heat transfer to the stairs that was not considered in the model. Overall the study demonstrates that FDS is capable of modelling fire development and smoke movement in a high rise building for well ventilated fires.     

装设电梯的高层建筑火灾条件下人员疏散时间计算方法

电梯在建筑物火灾情况下用于人员疏散的研究已经引起人们的重视。本文重点介绍采用电梯进行疏散时疏散时间计算方法,以及相应的研究成果。对于电梯用于高层建筑火灾疏散的研究具有重要意义。