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Passengers’ evacuation from a fire train in railway tunnel
Abstract
To acquire the evacuation time and average evacuation velocity of young adults under a train fire situation in railway tunnel, experiments and numerical simulations were conducted. According to the results, if the fire train continues running, the number of passengers in adjacent compartment affects the evacuation procedure in fire compartment greatly. The average velocity decreases by 45.7% when the adjacent compartment is 40% overloaded. If the fire train stops immediately, evacuation in the fire compartment is influenced greatly by the number and location of opened train doors. The average evacuation velocity decreases by 21.6% when two doors are opened on one side other than on two sides. Also, it is advisable to set the evacuation velocities of young adult male and female to be 1.2 m/s and 1.0 m/s respectively under train fire situation in railway tunnel. The results have important implications for rail safety.
... A train evacuation experiment conducted by the United States Federal Railway Administration (FRA) in Boston shows that average speed for men is 1.5 m/s and for women it is 1.3 m/s 39 . Yu et al. 34 believed that a walking speed of 1.0-1.2 m/s was reasonable based on evacuation simulations for Chinese trains. ...
... This study compared narrow-body subway cars with four-door pairs and wide-body cars with five-door pairs, but there was no consistent conclusion as to which performed better in evacuation and boarding/alighting. Widebody cars were found to be more conducive to passenger evacuation, as the increased number of doors meant a greater total exit width, consistent with the conclusion of Yu et al. 34 In addition, wide-body cars have wider aisles, which Qiu and Fang 22 suggest is an auxiliary factor that facilitates evacuation. Conversely, narrow-body subway cars are more conducive to boarding and alighting, as passengers have limited space for movement after boarding, thereby shortening the time for passenger flow exchange. ...
... Although the connectivity of subway cars does not affect the efficiency of passenger flow, connected cars are more conducive to the evacuation of passengers to adjacent cars in a fire 34 . Passenger circulation across cars also helps to alleviate congestion in individual cars and improve train utilization. ...
This study investigated the impact of subway car interior design on passenger evacuation and boarding/alighting efficiency. The usability of pedestrian agent models was verified through real-life experiments. A seven-factor orthogonal simulation experiment was designed, using key geometric features of the subway car interior as variables. The results of the computer simulation showed that the impact of subway car interior design factors on evacuation and boarding/alighting time was not entirely consistent, with seat layout and door width being the most important factors affecting passenger movement. In the evacuation scenario, only the connectivity of the subway car has no effect on evacuation time, while in the boarding and alighting scenario, seat layout, car type, door width, and foyer width all significantly affect boarding and alighting time. Multivariate regression models were established to predict evacuation and boarding/alighting times through design features, which can explain 86.7% and 58.9% of the time variation, respectively. The research results were used to guide subway car design, and the proposed new scheme demonstrated better performance.
The aim of this study is to explore the effect of different personnel attributes and the relationship between different people on evacuation efficiency in the case of a passenger ship fire. As such, this study proposes a speed correction method that considers human attributes and interactions between different populations. Firstly, a hesitant fuzzy set and hesitant fuzzy average operator are adopted to quantify four kinds of personnel attributes. Secondly, considering the influence of different people, this study extracts the formula for acceleration under the interactive influence of different groups of people. At the same time, based on the first-order linear relationship between velocity and acceleration, an interactive velocity correction method is presented in the evacuation of ship personnel. Finally, this study uses the personnel evacuation simulation software Pathfinder to conduct experiments, and introduces the corrected speed and the uncorrected speed into the evacuation simulation process, respectively. The results show that the simulation results of the revised speed plan are more consistent with reality.
There is an increasing number of road tunnels constructed in high-altitude areas of China. Generally, a tunnel is long and narrow. Therefore, when a fire breaks out in a tunnel, it is difficult to get rid of the smoke and the heat, which poses a threat to stranded people. The walking speed of people is the critical factor determining the evacuation time, particularly in high-altitude areas where the ambient pressure is low. In this study, a series of field tests were conducted by considering the environmental parameters to explore the effects of altitude on the people’s walking speed, and the considered parameters include the blood oxygen saturation of people, their heart rate and its variability parameters, ratings of perceived exertion, and walking speed. The results show that ambient pressure, which is about 97 kPa at an altitude of 500 m, decreases to approximately 64 kPa at an altitude of around 3850 m. In other words, the ambient pressure decreases with the increase in the altitude, and the difference in illumination between the internal tunnel and open environment is obvious. More specifically, several factors, including gender, age, tunnel environment, and altitude influence the walking speed, and corresponding reduction coefficients are introduced to reflect the influence of the factors on the walking speed. Finally, based on the field data, a reliable formula is proposed to predict the walking speed at different altitudes.
Once emergency situations take place in metro tunnels, the most common respond is moving toward next station. However, with metro system expanding outward from city centers, the distance between stations is increasing to tens of kilometers. It would take several minutes for a train to drive through a long tunnel, which wastes the evacuation time in the early stage of a disaster such as fire and increases the possibility of casualty. Therefore, we introduce an internal wind evacuation strategy for metro tunnel evacuation and compare the strategy with traditional station evacuation strategy and tunnel evacuation strategy. Besides, the train travel stage is taken into account in evacuation strategy comparison with the clarification of steps before the train stops. To analyze the smoke diffusion characteristics and the effect of smoke on evacuation, an actual metro tunnel in Beijing is modelled with FDS and BuildingEXODUS to acquire the smoke diffusion characteristics and evacuation performance of different strategies. The results indicate that: (1) the internal wind evacuation strategy is the best one when available. The station evacuation strategy is recommended only after the train has missed the last internal wind. (2) during the train travel stage, the diffusion range of smoke inside the train gradually increases, which would increase the likelihood of casualty. After the train arrives at the destination, the smoke diffusion range inside the car would soon stabilize. (3) stairs are the bottlenecks in tunnel evacuation which directly determines the flow rate and evacuation performance in destination. The length of train travel stage would also affect the selection of evacuation strategies.
The paper describes an application of numerical simulation of fire dynamics and evacuation of people in a tunnel. The software tool Fire Dynamics Simulator is used to simulate temperature resolution and development of smoke in a railway tunnel. Comparing to temperature curves which are usually used in the design stage results of the model show that the numerical model gives lower temperature of hot smoke layer. Outputs of the numerical simulation of fire also enable to improve models of evacuation of people during fires in tunnels. In the presented study the calculated high of smoke layer in the tunnel is in 10 min after the fire ignition lower than the level of 2.2 m which is considered as the maximal limit for safe evacuation. Simulation of the evacuation process in bigger scale together with fire dynamics can provide very valuable information about important security conditions like Available Safe Evacuation Time (ASET) vs Required Safe Evacuation Time (RSET). On given example in software EXODUS the paper summarizes selected results of evacuation model which should be in mind of a designer when preparing an evacuation plan.
Building information modelling (BIM) can be applied to tunnel engineering to address a number of problems, including complex structure, extensive design, long construction cycle and increased security risks. To promote the development of tunnel engineering in China, this paper combines actual cases, including the Xingu mountain tunnel and the Shigu Mountain tunnel, to systematically analyse BIM applications in tunnel engineering in China. The results indicate that BIM technology in tunnel engineering is currently mainly applied during the design stage rather than during construction and operation stages. The application of BIM technology in tunnel engineering covers many problems, such as a lack of standards, incompatibility of different software, disorganized management, complex combination with GIS (Geographic Information System), low utilization rate and poor awareness. In this study, through summary of related research results and engineering cases, suggestions are introduced and an outlook for the BIM application in tunnel engineering in China is presented, which provides guidance for design optimization, construction standards and later operation maintenance.
A three-dimensional mathematical model of the smoke movement in tunnel fires was established. Finite volume method was used to discretize the governing equations and the SIMPLE algorithm was employed to solve the governing equations. A scaling model (1:8) of the subway tunnel was built up based on similarity theory. Not only different positions of fire on the train, but also the different starting times of exhaust fan in the tunnel were considered. The disciplines of smoke temperature, smoke diffusion and wind velocity have then been compared under different the fire situations. The study is useful to analyze evacuating and controlling fire in emergent project of tunnel fire in a subway system.
An exploratory study of a train evacuation inside a tunnel was performed in order to study the effects of different train exit configurations on the flow rate of people through the exit. A total of 84 participants in the ages 18–40 years took part in the experiment, which was carried out on two separate days and involved 18 evacuation scenarios. The statistical analysis of the experiment demonstrated that the average flow rate capacity of the train exit was .3 persons per second and meter (p/s m) door width, including all scenarios. Four variables related to the train exit configuration were identified to significantly affect the flow rate of people: (1) a reduction of the train exit height increased the flow rate of people with on average .026 p/s m; (2) a change of tunnel floor material from concrete to macadam increased the flow rate of people with on average .015 p/s m; (3) an emergency ladder present in the train exit reduced the flow rate of people with on average .064 p/s m; and (4) a complete failure of the lighting inside the train reduced the flow rate of people with on average .029 p/s m. In addition, qualitative observations revealed a deferential behaviour among the participants in the train, caused by the people outside the train. It is therefore believed that the population density outside the train will significantly determine the flow rate capacity of the train exit during an evacuation.
At 16.3 km in length, the Young Dong Rail Tunnel will be the first long rail tunnel in Korea. This paper reviews the design of the ventilation and risk control systems undertaken by the successful Daewoo Consortium, starting from the definition of the relevant design criteria for both normal and emergency operation, and ending with detailed specifications for the civil and mechanical components, including a rescue station and three air exchangers for the purging of diesel emissions. The engineering analyses employed included Quantitative Risk Analysis, Computational Fluid Dynamics and one-dimensional aerodynamic calculations of the entire tunnel system.
The objective of this study is to establish and evaluate an Emergency Evacuation Capacity (EEC) model for key evacuation facilities in subway stations through analyzing key factors that affect the emergency evacuation These key facilities, which include exit, stairway, passage and turnstile, are analyzed from three aspects: characteristic of evacuees, evacuation facility, evacuation organization and management. The emergency evacuation capacity model for subway station is built based on pedestrian flow theory. In addition, a case study is conducted to look at the handling capacity of the selected station. The result from this study will be beneficial for guiding and improving subway station design. It has significance to improving emergency response ability of rail transit system.
Too often, validation of computer models is considered as a "once and forget" task. In this paper a systematic and graduated approach to evacuation model validation is suggested. This involves, 1. Component testing 2. Functional validation 3. Qualitative validation 4. Quantitative validation Viewed in this manner, validation is considered an on-going activity and an integral part of the life cycle of the software. While the first three components of the validation protocol pose little or no significant problems, the task of quantitative validation poses a number of challenges, the most significant being a shortage of suitable experimental data. In addition, the validation protocol used in the development of the EXODUS suite of evacuation models is briefly examined. Finally, while this discussion focuses on the validation of evacuation models, the principles of the protocol can be equally applied to fire models.
Previous fire accidents have shown that fires in underground transportation systems, e.g., tunnels and underground stations,
can cause many fatalities. It is therefore important in fire safety design to give adequate consideration to all aspects related
to evacuation. The main purpose of this paper is to provide guidance to engineers involved in the design of underground transportation
systems, and to create a basis for future research in the area. A review of previously reported fire accidents and of empirical
research is performed. The review of accidents is based on a theoretical framework, namely four accepted human behaviour theories,
which can be used in the fire safety design of underground transportation systems. Factors important for fire evacuation in
these types of facilities are also presented, and data related to these factors are summarised. The review reveals many potential
solutions to commonly observed evacuation problems, but it also shows that there is room for further future research in the
area.
To cope with tunnel frost damage, studies on prevention methods are routinely conducted to improve environmental protection and energy saving. Based on field investigations, the main available thermal insulation methods and their application are discussed and analysed in this paper. The results show that passive measures, such as a thermal insulation layer or door, cannot completely avoid frost damage. Construction investment of the electric heat tracing (EHT) system is lower at the early stage, but a large investment in operation and pollution problems are needed in the later period. As renewable, clean and environmentally friendly primary energy, geothermal energy can realize energy-saving and emission-reduction. Furthermore, our research team proposed the optimization design method for tunnel heat insulation and anti-freezing by using geothermal energy and presented the challenges for future applications of the ground-source heat pump (GSHP) system in tunnels. The results regarding energy conservation from this review can provide useful technical support in design, operation and management of tunnels in cold regions.
Using the latest advances in virtual reality (VR) technologies, it is possible to create immersive virtual environments (IVEs) that can be used for behavioral experiments in controlled setups to examine individual evacuee behaviors. As a first step to achieving sufficient ecological validity, this study proposes an approach for assessing the sense of presence of the subjects performing virtual evacuation tasks, and this assessment can serve as an indirect indicator of the overall validity of the experiments. The proposed approach integrates a set of subjective and objective measures to assess the subjects’ emotional responses, including emotional valence and emotional arousal, which are highly reflective of their sense of presence in the IVEs. Three IVEs are developed, presenting an apartment under normal or fire emergency situations with different levels of realism. The subjects were asked to perform an evacuation task in all IVEs, and their emotional responses were monitored and analyzed throughout the experiments. The results show that the proposed approach can not only detect changes in subjects’ emotions triggered by the IVEs but can differentiate subjects’ emotions when they were immersed in IVEs with different levels of realism. These findings suggest that it is feasible to use the proposed approach to assess the sense of presence experienced by subjects conducting virtual evacuation tasks and ultimately the level of ecological validity of IVE-based evacuation studies.
The paper presents the results of an analysis of the ‘emergency response system’ at the time of the 1996 Channel tunnel fire accident. In particular, the analysis focuses on the events that unfolded once the incident train had stopped; i.e., the evacuation of the passengers and the train crew. The approach has been the use of a ‘Tunnel Fire Safety Management System’ (‘TFSMS’) Model as a ‘template’ for comparison with the ‘emergency system’ in place at the time. In particular, responding to the following question being addressed: could the time of evacuation of the incident train crew and passengers be less that the time it took? The answer is Yes. Some relevant findings associated with the deficiencies in the existing 'system' have been highlighted by the model.
A new type of train configuration, known as Open Wide Gangway (OWG) is becoming popular, particularly in underground environments. Previous fire modelling analysis demonstrated that the OWG configuration was considered safe as or safer than conventional configurations as it reduced the likelihood of flashover. However, these studies have ignored the impact on evacuation of the spread of fire effluent to non-fire cars. Here we explore the fire safety offered by conventional and OWG configurations using coupled fire and evacuation modelling techniques. Two tunnel train situations are considered: one in which the car side doors are available for evacuation (train in a wide tunnel) and the other in which only the end cab doors are available (train in a narrow tunnel). Two population configurations are considered, fully and half loaded. Two ignition sources are also considered, one representing an accidental fire and the other an arson fire. The analysis demonstrates that while the OWG configuration may produce improved fire performance in the car of fire origin compared to the conventional configuration, if the interaction of the fire effluent with the evacuating passengers is considered, the OWG configuration results in a significantly greater number of casualties in virtually all the scenarios considered. Copyright
The safety of a running train on fire in a tunnel is a key issue for rescue operations, and the train velocity is mainly related to its safety. In this study, the relationship between the wind velocity and heat release rate (HRR), temperature field around the train, and flame/smoke pervasion rule were investigated under the conditions of variable train velocity, fire location, and fire source location. Beijing Metro was considered as a typical example, in which the safe velocity was estimated to be ∼41.83 km h⁻¹. Assuming the occurrence of fire at the center of the train, the numerical simulations of the flow field using the sliding grid of CFD were performed for a full-scale tunnel under different HRRs. When the fire source reached to the target section, the velocities of all the monitoring points rapidly increased. The velocities increased as the train tail arrived at the target section. The velocities at the measuring points increased with the increase in height, excluding the value of the position with a distance of 0.025 m from the tunnel ceiling. The average temperature and concentration of smoke in the annular space between the train and tunnel ceiling had the minimum values when the running train on fire moved with a speed of 45 km h⁻¹. Thus, the safe velocity of a subway train on fire should be managed between 41.83 km h⁻¹ and 45 km h⁻¹.
The emergency response to a case when a high-speed train caught fire in tunnel and the way of passengers evacuation before the train stopped were analyzed first. It is suggested that passengers in the burning coach should evacuate to adjacent coaches before the train stops instead of breaking the windows of the burning coach and the train on fire should keep on moving forward until it leaves the tunnel or arrives at the nearest emergent rescue station. A CRH1 train fire occurring in the Shiziyang Tunnel of the Guangzhou-Shenzhen-Hongkong Passenger Dedicated Line was taken as an example to simulate the case of passenger evacuation when a train on fire was forced to stop in a tunnel. Smoke spread and the passenger evacuation process for the worst-case scenario in the tunnel were simulated, the rationality of setting of the parameters such as the rescue passage width, cross passage entrance width and cross passage spacing was evaluated. The results show as follows: A fire occurring in the middle part of a train is more dangerous, the danger to passengers is mainly from the toxicity and opacity of smoke; the rescue passage width of 1.5 m, the cross passage entrance width of 1.5 m and the maximum cross passage spacing of 500 m can satisfy safety evacuation requirements, however, crowding occurs near the train and the safety factor of evacuation is low; for newly built tunnels of passenger dedicated lines, It is recommended that both rescue passage width and cross passage entrance width are more than 2.0 m.
A case study on the analysis of evacuation travel paths in virtual reality (VR) tunnel fire experiments is presented to increase the understanding on evacuation behaviour. A novel method based on the study of the parametric equations of the occupants’ evacuation travel paths using vector operators inspired by functional analysis theory and the new concept of interaction areas (IAs) is introduced. IAs are presented and calculated in order to represent the distance of an occupant from a reference point (e.g., an emergency exit, the fire source, etc.) over time. The method allows comparisons of travel paths between experimental groups as well as comparisons with reference paths (e.g. user-defined paths, real-world paths, etc.). Results show that a common assumption employed by evacuation models (the use of a hypothetical path based on the shortest distance) may be an over-simplistic approximation of the evacuation paths.
The construction of metro in China is in a period of an unprecedented development in recent years, and the passengers are in high density within the metro during the operation time, the problem of occupant safety in emergencies has attracted more and more attentions. During the design and operation stages, modeling of the metro station evacuation capacity by using the computational models is an effective measure for guaranteeing the metro evacuation safety in the future. In this article, the safety strategy of evacuation in metro stations is first investigated and established, which involves the occupants needed to be evacuated, the evacuation route, and the safety zone. Then, an engineering calculation method for the metro station evacuation time is proposed. Based on the experimental data, simulation of evacuation process in different fire cases is conducted by using an agent-based model, so as to study the features of occupant evacuation behavior, the evacuation time, the passage flow rate, and the strategy of using the escalator as evacuation passage. These conclusions will be helpful for guiding the safe evacuation design of metros in China.
The phase from the design to the operation of tunnels for railbound public transportation systems proves to be extremely protracted in practice. This is due to the necessary approval procedures and extremely different appraisals pertaining to safety for instance. The design phase can be appreciably reduced if a standard emergency scenario is presented, for which a suitable safety concept must be available. Experts then decide on the case of fire as a standard scenario from possible emergency scenarios by dint of which the required safety considerations are to be carried out for new structures so that a standard basis for planning is created in Germany. The principal approach is shown for example for designing underground stations so that persons can rescue themselves and be rescued through establishing short evacuation periods and long smoke proliferation periods.
A fire within an underground rail rapid transit system, particularly in a tunnel location, poses a highly hazardous condition to passengers, transit employees and emergency response personnel. Certain considerations in the improvement of fire safety are universal to all transit systems.A number of problems have been identified by the National Transportation Safety Board, an independent U.S. government accident investigation agency, as warranting immediate attention to minimize the threats posed. The Safety Board's concern was heightened by several accidents on rail rapid transit systems involving many passengers. The fact that during peak hours, a single rail rapid transit train could carry as many as 1500 to 2000 passengers was not overlooked. Specifically, the Safety Board reviewed the following topical areas which may complicate fire and life safety in confined rail rapid transit tunnel locations: - transit car materials: combustibility and toxicity;- emergency tunnel ventilation;- tunnel emergency evacuation considerations;- communications;- breathing equipment;- mobility.It is hoped that the lessons learned in our accident investigations involving fire and emergency evacuations will add to the collective knowledge of transit systems and emergency response personnel to further minimize the hazards.
Rescue stations have been newly designed in some super-long mountain railway tunnels of China such as over 30 km long, as a new type of strategic counteract design for fire accident in tunnels. Water mist fire suppression systems are needed to be installed in such rescue stations to control the train fire. However, there is no design engineering experience for it. In this article, a full-scale experimental facility was built to study the fire suppression performance of water mist system in such railway tunnel rescue station. A series of full-scale tests was preliminarily conducted considering the fire position was on top of, inside, and under the train carriage with gasoline pool fire and wood crib fire used as fire sources. A design of water mist suppression system for such a fire scenario was presented, and its performance was tested. Experimental data on temperature, CO concentration, and radiation flux were collected and analyzed. The results showed that the water mist system could control fires, cool the air temperature in the rescue station, and strongly reduce the radiant heat flux in the vicinity of the fire source under various ventilation conditions. However, the visibility of the rescue station was much deteriorated after the injection of water mist, so that emergency lights and evacuation lights are necessary for personnel evacuation. The changes of fire extinguishing time with longitudinal ventilation velocities showed that longitudinal ventilation could provide both favorable and unfavorable conditions for water mist fire extinguishment. So, to achieve efficient fire suppression performance of water mist system, attention might be paid to the controls of tunnel ventilation system in the event of a fire in a railway tunnel rescue station. The design of the water mist system and the full-scale experimental data on the fire suppression performance presented in this article may serve as a reference for such engineering applications.
This paper uses egress modelling to explore the impact that crew procedures have on evacuating two
high-speed trains under different fire scenarios. The paper begins by analysing an evacuation drill
performed by the Spanish Railroad Administration, RENFE Operadora. This analysis is used to obtain
input data for the simulations. The second part of the paper analyses the effects of passenger preevacuation
activities and train crew procedures (when the fire is detected and the train is still in
motion). For each scenario, multiple simulations are performed to capture the stochastic variations in
egress times. The results have important implications for rail safety and also show that there are
qualitative and quantitative advantages for evacuating under conditions controlled by the train crew
rather than using a self-rescue strategy, which allows us to make safety recommendations for
managing emergencies.
This paper addresses the problem of representing the impact of different emergency exit signs during the evacuation of a tunnel when using two different evacuation models (i.e. FDS+Evac and buildingEXODUS). Both models allow the user to represent the impact of smoke upon the evacuee. The models are calibrated (1) considering the nature of the models themselves, (2) by deriving assumptions from previous experiments and literature, (3) using new data produced from experimental work performed by Lund University. The purpose of this paper is to demonstrate the activities required of the user to configure sophisticated egress tools given the scenario examined and the alternatives available in representing evacuee behaviour. Model results show that the differences in terms of emergency exit usage are affected by the degree of modelling sophistication employed and user expertise. It is demonstrated that evacuee performance may be misrepresented through indiscriminate use of default settings. Results are instead consistent between the models when their input is calibrated implicitly (given the availability of experimental data) or explicitly (employing the exit choice sub-algorithms embedded in the model). The scenarios examined are deliberately designed to be a superset of experimental trials currently being conducted about exit choice in a tunnel. The scope is to allow a blind model comparison to take place once the experiments are completed. This will be reported in a future article.
Fire incidents inside passenger trains constitute a significant risk factor for life safety. Therefore, it is necessary to
count on a suitable evacuation strategy, during the instants previous to the rail vehicle halt and the subsequently evacuation.
In this paper, the evacuation of passengers from different fire scenarios and several evacuation conditions were investigated.
The analysis was divided into two stages of the evacuation process considering two different high speed trains: (1)the movement
and behaviour of passengers in fire scenarios inside the vehicle before the train stopped, and (2)the analysis of train evacuation
under different conditions. The results, obtained by means of the egress model STEPS (see MacDonald, STEPS Simulation of Transient
and Pedestrian Movements User Manual), allowed to determine the influence of the limitations of the different train geometries
under different evacuation conditions, give an estimation of the evacuation times and analyse the impact of human parameters
considered in the evacuation process.
Traffic operations in public walking spaces are to a large extent determined by differences in pedestrian trafficdemand and infrastructure supply. Congestion occurs when pedestrian traffic demand exceeds the capacity.In turn, the latter is determined by a number of factors, such as the width of the bottleneck and the wall surface, as well as the interaction behavior of the pedestrians passing the bottleneck.
This article discusses experimental findings of microscopic pedestrian behavior in case of bottlenecks. Results for both a narrow bottleneck and a wide bottleneck are discussed and compared to the results of an experiment without a bottleneck. It is shown how pedestrians inside bottlenecks effectively form layers or trails, the distance between which is approximately 45 cm. This is less than the effective width of a single pedestrian, which is around 55 cm. The layers are thus overlapping, a phenomenon which is referred to as the “zipper” effect. The pedestrians within these layers follow each other at 1.3 seconds, irrespective of the considered experiment. For the narrow bottleneck case (width of one meter) two layers are formed; for the wide bottleneck case (width of two meters), four or five layers are formed, although the life span of these layers is rather small.
The zipper effect causes the capacity of the bottleneck to increase in a stepwise fashion with the width of the bottleneck, at least for bottlenecks of moderate width (less than 3 m). This has substantial implications for the design of walking facilities.
EXODUS is a prototype egress model designed to simulate the evacuation of large numbers of individuals from an enclosure. The model tracks the trajectory of individuals as they make their way out of the enclosure, or are overcome by fire hazards such as heat and toxic gases. The software is expert system based, the progressive motion and behaviour of each individual being determined by a set of heuristics or rules. EXODUS is intended, primarily, for use in mass-transport vehicles such as aircraft, but it also has application to cinema, theatres and lecture halls. EXODUS comprises five core interacting components—the movement, behaviour, passenger, hazard and toxicity submodels. These sub-components are described and model results are compared with experimental data generated from a series of competitive aircraft evacuation experiments. The model is successful in predicting the experimental trends. Finally, the capabilities of the model are demonstrated through a series of hypothetical evacuation scenarios involving a wide-body aircraft.
The evacuation process from a dark room with an exit is investigated by the use of the biased random walk model. We clarify the statistical properties of the walker escaping from the room through the exit. The evacuation from the room without visibility consists of two processes: (1) the biased random walk from an initial position to the wall and (2) the second walk following the wall. The following statistical quantities are derived by using a lot of simulating trajectories: the probability density distributions of (1) the number of steps of the biased random walk to the wall, (2) the first contact point on the wall, and (3) the number of steps of the second walk on the wall. The third statistical distribution is connected closely with the first and second distributions. Their distributions depend highly on the scenarios of the walker. We show the effects of the initial position, drift, and scenario on the mean escape time.
The most crucial aspect of a building's safety in the face of fire is the possibility of safe escape. An important precondition is that its fire safety facilities enable independent and adequate fire response performances by the building's occupants. In practice, it appears that the measures currently required by law do not always provide the support that people in burning buildings need. Consequently, understanding how individuals behave in the case of fire and fire evacuation is essential if we are to bring fire safety measures into line with occupants’ needs during an incident. This paper contains a review of the available literature on human behaviour in a fire so far as building safety is concerned. The findings are presented as an overview of the critical factors which determine occupants’ fire response performances, namely the characteristics of fire, human beings and buildings. The study highlights that some of the assumptions about the existing paradigm of fire safety in buildings are not consistent with the knowledge set out in the literature. The key observation is that psychonomics appear to have significant influence on occupants’ fire response performances. Accordingly, the traditional approach to fire safety will have to be supplemented by scientific knowledge from this field. Hence, there is a need for a new approach to fire safety design in buildings, which is set out herein.
On the 11th August 1982, a combination of electrical faults led to an underfloor fire on the last car of a Piccadily Line train. The background, circumstances and events which occurred are described. One of the features of this fire was the very large amount of smoke emitted by relatively small areas of burning material.
In this paper, the buildingEXODUS evacuation model is described and discussed and attempts at qualitative and quantitative model validation are presented. The data sets used for validation are the Stapelfeldt and Milburn House evacuation data. As part of the validation exercise, the sensitivity of the buildingEXODUS predictions to a range of variables is examined, including occupant drive, occupant location, exit flow capacity, exit size, occupant response times and geometry definition. An important consideration that has been highlighted by this work is that any validation exercise must be scrutinised to identify both the results generated and the considerations and assumptions on which they are based. During the course of the validation exercise, both data sets were found to be less than ideal for the purpose of validating complex evacuation models. However, the buildingEXODUS evacuation model was found to be able to produce reasonable qualitative and quantitative agreement with the experimental data.
Computer based analysis of evacuation can be performed using one of three different approaches, namely optimisation, simulation or risk assessment. Furthermore, within each approach different means of representing the enclosure, the population, and the behaviour of the population are possible. The myriad of approaches which are available has led to the development of some 22 different evacuation models. This article attempts to describe each of the modelling approaches adopted and critically review the inherent capabilities of each approach. The review is based on available published literature.
Tunnel emergency egress and the mid-train fire
- M P Colino
The new piarc report on fire and smoke control in road tunnels
- Lacroix