Shorter Evacuation Time Research Articles

Evaluation of Tsunami Evacuation Plans for an Underground Mall Using an Agent-Based Model

Tsunamis resulting from earthquakes can cause extensive damage, including infrastructure destruction, injuries, and fatalities. To address these risks, numerous tsunami evacuation simulations have been conducted to assess evacuation strategies and identify issues, particularly in Japan, where the Nankai Trough earthquake is anticipated, affecting underground malls in urban areas. Our previous research primarily focused on evacuating from underground to the surface, neglecting surface evacuation. Therefore, this study extended the previous study to include horizontal evacuation following the exit from the underground mall to ground level. It also considered the impact of pedestrian road crossings as interactions with vehicular traffic within the simulation to enhance realism and verify the evacuation risk. The study also explores scenarios where evacuation guide stairs are unavailable, comparing the effectiveness of alternative staircases in the evacuation plan. Results indicate that while using alternative staircases temporarily increases the number of evacuees reaching the surface, road crossings on evacuation routes become significant bottlenecks, leading to surface congestion and delayed evacuations. This raises doubts about the effectiveness of alternative staircases and highlights the need to consider alternative evacuation routes as a secondary plan. Additionally, the study reveals that reduced pedestrian flow at road crossings can significantly impact on evacuation times. Ultimately, this study demonstrated that achieving a short evacuation time from underground malls to the ground level might not always yield the best evacuation plan. It underscored the importance of considering aboveground factors in evacuation planning to ensure safety in the event of a tsunami caused by an earthquake.

산후조리원의 성능위주설계에 의한 피난안전성 증대방안

This study sought to propose measures for improving evacuation safety. This was achieved by calculating the habitable time using a fire and evacuation simulation program for the Postnatal care center currently in operation, and comparing and analyzing it with the evacuation required time. Assuming the presence of a fire caused by the overheating of electric heaters in a maternity room, the habitable time was calculated through fire simulation, and the occupant's evacuation time, according neonatal unit arrangement, was compared and analyzed with the habitable time. It was found that evacuation safety was not secured among the postnatal care center subjects in this simulation as the evacuation time exceeded the habitable time. In the analysis of evacuation time, changes in evacuation time were compared and analyzed by setting up scenarios such as dispersing neonatal units on one floor and distributing them on two floors. As a result of the evacuation simulation, and based upon the shortest evacuation time, it was found that many people would not be able to evacuate if the neonatal unit was only placed on the highest floor and in one location. Therefore, regulations for placing the neonatal unit and the postnatal care center on the lower floors are necessary.

Simülasyon Modeli Kullanarak Bir Üniversitede Acil Durum Tahliye Planı Oluşturulması

Many countries have experienced a lot of loss of life and material losses in many incidents due to natural or technological disasters. Planned and systematic action is required to manage emergencies. For this, a successful plan must be prepared. In order for the emergency management to be successful, it is necessary to successfully evacuate people from the building in the event of a disaster. Emergency evacuation plans, evacuation drills and training should be provided. Simulations and models have often been one of the methods people use to study events. How solutions should be created for the events encountered were examined with simulations. With emergency evacuation simulations, an emergency management plan can be made close to reality. This study was carried out in a university building. In this 3-storey building, there are students, lecturers and working personnel. The best emergency evacuation plan to be applied in an emergency has been researched. It was aimed to create a plan with the shortest evacuation time by making experiments with the simulation program. Pathfinder simulation program was used in this study. In the first part, 11 scenarios related to the routing variability to the emergency exit doors were created. It is aimed to create a plan with the best evacuation time. In the second part, 5 scenarios were created about the situations where the emergency exit doors are locked and the doors are unusable for certain periods. The effects of these disruptions on the evacuation period were examined.

Optimization of an Airport Departure Hall Evacuation Plan Based on a Time-Varying Network Algorithm

As a highly dense area for passengers, the airport departure hall is particularly characterized by the easy gathering of passengers, irregularity, and difficulty in command, which has become a high incidence of emergencies. For the evacuation problem in case of emergencies, the vast majority of passengers randomly choose the shortest path from the exit to escape, which will lead to congestion at some nodes and prolonging of the evacuation time. Therefore, this study proposes a better evacuation method considering the dynamic change in the spatiotemporal congestion of passengers. First, this paper constructs an evacuation network diagram for the departure hall of the Shenzhen Bao’an International Airport terminal building, simplifies the evacuation process into point-to-point evacuation, and proposes a time-varying network algorithm to optimize the emergency evacuation of the airport. Second, on the premise of obtaining the number and dynamic distribution of passengers in each area in real time, a linear programming model with the shortest evacuation time as the optimization objective is established, and the current optimal evacuation path of passengers is dynamically calculated. Finally, the two evacuation methods, random evacuation and evacuation, based on a time-varying network algorithm are simulated and analyzed by AnyLogic software. The results show that the evacuation scheme based on the time-varying network algorithm can effectively relieve the passenger congestion of some evacuation paths and safety exits. The evacuation time is reduced by 74 s, the evacuation efficiency is improved by 14%, passenger congestion at some evacuation routes and safety exits can be effectively relieved, and the global optimization of the emergency evacuation of passengers is achieved.

Optimization of Shelter Location Based on a Combined Static/Dynamic Two-Stage Optimization Methodology: A Case Study in the Central Urban Area of Xinyi City, China

Determining how to reasonably allocate shelters in the central area of the city and improve evacuation efficiency are important issues in the field of urban disaster prevention. This paper introduces the methodology and mathematical model from the field of crowd emergency evacuation to shelter location optimization. Moreover, a shelter location optimization method based on the combination of static network analysis and dynamic evacuation simulation is proposed. The construction costs and evacuation times are taken as the objective functions. In the first stage, based on the static network analysis, a circular evacuation allocation rule based on the gravity model is proposed, and the genetic algorithm is then designed to solve the feasible schemes with the lowest shelter construction costs. In the second stage, the evacuation time is taken as the optimization objective. The age differences of refugees, the selection of evacuation routes, and the behavior of adults helping children and the elderly are simulated in a dynamic evacuation simulation model. The traditional social force model is improved to conduct a regional evacuation simulation and determine the optimal scheme with the shortest evacuation time. Finally, the central urban area of Xinyi City, Jiangsu Province, China, is taken as an empirical case.

Large-Scale Evacuation Shelter Selection Method Through Iterations of Pedestrian Simulations With Dynamic Congestion Reproduction

It is necessary to optimize evacuation guidance to shelters in short evacuation time. The state-of-the-art method based on an idea of combinatorial optimization problems related to evacuees’ locations and the capacities of nearby shelters has been developed, while it cannot mitigate the effect of congestion on roads/streets after evacuation starts. In this study, to cover this problem, we develop a new method that utilizes simulations for estimating the effect of congestion on roads/streets during evacuation and reassigning shelters to evacuees based on the simulation results. By iterating this step, our method derives the congestion-aware solutions for shelter selection that can realize more smooth evacuation. To evaluate our method, we conducted multi-agent simulations assuming a disaster situation in a sightseeing spot. Specifically, we examined a hypothetical case scenario involving the evacuation of 30,000 visitors from the Gion Festival. We compared the proposed method with conventional methods, such as the nearest shelter selection method and our previous method. We found that our proposed method reduced average and total evacuation time and congestion on roads compared to the conventional methods including the nearest shelter selection method and our previous method that only employs combinatorial optimization without estimating congestion. From this result, our idea of simulation-based congestion estimation has an impact of easing congestion during evacuation and preventing overcapacity of shelters at the same time. It shows the possibilities of help in developing congestion-aware evacuation strategies in emergency situations of crowded areas like huge cities or sightseeing spots.

Smart-Guided Pedestrian Emergency Evacuation in Slender-Shape Infrastructure with Digital Twin Simulations

Rapid exploitation of city underground space has led to the development of increasingly more underground slender-shape infrastructure like pedestrian tunnels, concourses, subway walkways, underground shopping streets, etc. Pedestrian evacuation in those public places in case of emergency can be disastrous if not properly guided. Therefore, it is important to understand how to enhance the evacuation efficiency through proper active guidance. In this study, we propose a digital twin based guiding system for pedestrian emergency evacuation inside a slender-shape infrastructure, aiming at enhancing the overall evacuation efficiency. Composition and calibration process of the guiding system are described, and a cellular automata based model is established to serve as the digital twin model. Two guidance strategies, namely traditional fixed guidance and smart guidance, are adopted by the digital twin to generate guidance instructions. A smart guidance strategy using a semi-empirical approach is proposed based on the understanding of the free movement and congested movement of pedestrian flow. Systems under different guiding strategies are compared and discussed over their effectiveness to promote excavation efficiency in different pedestrian population distribution settings. The simulation results show that a system under smart guidance tends to have shorter evacuation time (up to 23.8% time saving) and performs with more stability for pedestrian evacuations over the traditional fixed guided systems. The study provides insight for potential real applications of a similar kind.

Effect of architectural adjustments on pedestrian flow at bottleneck

In the last decades, a series of terrible accidents happened within pedestrian crowds, which makes crowd dynamic a significant issue to be investigated. Literature reviews show that pedestrian flow presents different features within different architectural layout. In this paper, pedestrian movement properties at bottleneck are studied by carrying out series of experiments under laboratory condition. The influence of door sizes and exit locations on pedestrian crowd flow is investigated. It was found that larger door width resulted in shorter evacuation time and faster flow rate. By comparing the fundamental diagram among crowd evacuation, the average velocity increases as the width increases under the same density condition. Interestingly, the influence of the boundary layer, as well as the effective width on pedestrian crowd dynamic, was clearly observed. Our results suggest that the combination of exit width and location resulted in a synergistic effect, but the exit widths gradually became the most important factor influencing the flow rate.

Testing the Process of Evacuation from the Passenger Aircraft with the Use of Computer Simulation

Aim: The main aim of the study was to investigate the possibility to use the Pathfinder simulation software to determine the duration of an evacuation and to plan its course for various scenarios of evacuation organisation, for specific profiles and behaviours of passengers and on-board personnel, and for a specific geometrical arrangement of the passenger cabin of a selected passenger aircraft. In addition, the paper discusses selected factors that affect the evacuation from the passenger aircraft. Project and methods: The Pathfinder software used in the research has the graphical interface to create an evacuation simulation model (2D and 3D) as well as tools to visualise the results. Pathfinder is based on artificial intelligence algorithms, in which each passenger has a number of individual features that can influence his/her movements and decisions during the simulation. The simulation of people's movement is determined by their profiles and behaviours, the parameters of which can be entered by means of probability distributions, which makes it possible to take into account the stochastic nature of the evacuation process. Results: The Boeing 787 Dreamliner was selected for the study, for which six options for simulating the evacuation of 252 passengers and eight members of on-board personnel were conducted. The shortest evacuation time was achieved by changing the even distribution of the number of passengers to the individual emergency exits, thus avoiding congestions in sensitive areas of the passenger cabin. The increase in passengers' maximum speed has paradoxically increased evacuation times, as it has increased the intensity of passenger collisions. It was found that one of the key issues affecting the timing of an evacuation is the proper organisation of the evacuation by on-board personnel, who, by guiding passengers through the geometrically most advantageous passageways, results in the fastest possible evacuation. The simulations in variants five and six have achieved satisfactory evacuation times, which are within the emergency aircraft evacuation time limit required in a certification process. Conclusions: The presented simulation models, the results obtained, and the wide range of possibilities of three-dimensional visualisation of research results give a rational basis for the use of Pathfinder software for testing the evacuation process and thus: for the usage in the aircraft design process, for preparing aircrafts for tests, for shaping evacuation procedures, for on-board personnel training and for air accident investigation.

Effect of dangerous source on evacuation dynamics in pedestrian counter flow

The modeling of evacuation dynamics under a sudden dangerous source is an important and interesting topic in pedestrian counter flow. In this paper, an extended cellular automata model is proposed to simulate pedestrian evacuation in a channel by considering the sudden dangerous source effect, in which the concept of core radius and edge radius of dangerous source are introduced to quantitatively reflect the magnitude of the dangerous source. The parameter of influence power of pedestrian is firstly used to describe the propagation of danger information, and a new algorithm of calculating the optimal directions is presented to reflect the decisions-making behavior of pedestrian. The influences of the position, magnitude of the dangerous source and the influence power of pedestrian on evacuation process in the channel are investigated. And the spatiotemporal dynamic characteristic during the evacuation process is also discussed. The simulation results show that considering the propagation of danger information will reduce the total evacuation time considerably. Without the propagation of danger information, at the medium density, the evacuation efficiency is higher when the dangerous source is located at the side of the channel. However, at the high density, the shortest evacuation time appears when the dangerous source is located in the central partition line of the channel. Furthermore, the strength of influence power among pedestrians plays an important role on evacuation efficiency. In particular, there are important differences in the jamming mechanisms under different positions and magnitude of dangerous source.

Evacuation Path Optimization Algorithm for Inland River Passenger Ship in Emergency Situation

ABSTRACT Zhang, Y.; Zhang, D., and Jin, J., 2018. Evacuation path optimization algorithm for inland river passenger ship in emergency situation. In: Liu, Z.L. and Mi, C. (eds.), Advances in Sustainable Port and Ocean Engineering. Journal of Coastal Research, Special Issue No. 83, pp. 256–260. Coconut Creek (Florida), ISSN 0749-0208. The current ant colony algorithm has higher congestion and evacuation risk for the evacuation path of the personnel in hatchway. Therefore, an optimization algorithm based on particle swarm for evacuation path of the personnel in hatchway is proposed. In the algorithm, the shortest evacuation time is taken as the goal, and the corresponding emergency evacuation model is established. Then, the particle swarm optimization algorithm is used to solve the model. In the process, the velocity and position of the particle are calculated, and the optimal velocity and position are obtained by iteration. Finally, based on fitness function, an evacuation model for the personnel in hatchwa...

Simulating pre-evacuation times using hazard-based duration models: Is waiting strategy more efficient than instant response?

In an indoor evacuation scenario, an early decision to be made by each occupant is when to initiate the (decisive) evacuation movement, a decision that determines the pre-evacuation (or pre-movement) time. We employ a class of econometric models, proportional hazard duration models, to simulate the probabilistic relation between the pre-movement times and the occupant’s proximity to exits at the onset of evacuations. This is based on the empirically-supported assumption that occupants that are relatively further from exit locations when the evacuation cue is perceived, take relatively longer times to initiate their evacuation movement. Implementing these parametric models and using extensive numerical simulations, we investigate the effects of (various degrees and forms of) pre-movement-time heterogeneity on the evacuation efficiency. This is to revisit and test the anecdotal idea that occupants’ collective instant rush hinders evacuation processes. In testing this assumption, we examined whether heterogeneity (i.e. variation) in pre-movement times can lead to better outcomes (i.e. shorter evacuation times). Our analyses included both purely-random heterogeneity as well as strategized heterogeneity, one in which occupants nearer to exits are prioritised, as a (probabilistic) waiting strategy. We observed that the instant movement of occupants led to bigger crowd jams at bottlenecks and created greater degrees of congestion which sustained for longer amounts of time. However, from a time-minimisation perspective, collective instant movement was invariably the best strategy. Neither the random nor the strategized forms of pre-movement-time heterogeneity resulted in any shorter evacuation time than when all occupants initiated their movement instantly. In fact, increasing the degree of pre-movement-time heterogeneity led monotonically to longer evacuation times, despite making the evacuation more orderly. This finding suggests that advising occupants to avoid instant rush may not be a time-optimal strategy, even though it mitigates congestion. The finding has not been tested in relation to high-rise buildings and needs further investigation in that context.

Evolution of pedestrian evacuation considering different human behaviors

Pedestrian evacuation becomes more complicated when different human behaviors are considered. In this paper, pedestrian evacuation considering two different kinds of human behaviors is studied by using a cellular automaton (CA) model. Two types of evacuees, cooperators and defectors, are initially randomly distributed in a square room with one exit and they interact with their neighbors following the snowdrift game theory (characterized by the parameter “[Formula: see text]”) during the evacuation process. Cooperators and defectors are mutually changed according to two typically different kinds of evacuees’ judgements, namely, judgement based on neighbors’ strategies (we call it herding behavior) and judgement based on neighbors’ payoffs (we call it independent behavior), which leads to the corresponding evacuee clusters. It is found from a large amount of numerical simulations that the proportions of the corresponding evacuee clusters are evolved to respectively consistent states despite 11 typically different initial evacuee cluster ratios, largely owing to self-organization effect. Moreover, for other 200 randomly chosen initial evacuee cluster ratios, Monte-Carlo simulations show that the proportions of the corresponding evacuee clusters are evolved stably, without any oscillation, and when the initial number of pedestrians of two different kinds of behaviors are comparable, the proportions are evolved to respectively consistent states despite different initial evacuee cluster ratios, indicating that some regular phenomena occur during the evacuation process. Furthermore, it is found that the moderate values of [Formula: see text] is necessary for short evacuation time, and for the fixed values of [Formula: see text], the initial ratio of pedestrians of herding behavior has a great influence on the final evacuation time.

Bilevel Traffic Evacuation Model and Algorithm Design for Large-Scale Activities

This paper establishes a bilevel planning model with one master and multiple slaves to solve traffic evacuation problems. The minimum evacuation network saturation and shortest evacuation time are used as the objective functions for the upper- and lower-level models, respectively. The optimizing conditions of this model are also analyzed. An improved particle swarm optimization (PSO) method is proposed by introducing an electromagnetism-like mechanism to solve the bilevel model and enhance its convergence efficiency. A case study is carried out using the Nanjing Olympic Sports Center. The results indicate that, for large-scale activities, the average evacuation time of the classic model is shorter but the road saturation distribution is more uneven. Thus, the overall evacuation efficiency of the network is not high. For induced emergencies, the evacuation time of the bilevel planning model is shortened. When the audience arrival rate is increased from 50% to 100%, the evacuation time is shortened from 22% to 35%, indicating that the optimization effect of the bilevel planning model is more effective compared to the classic model. Therefore, the model and algorithm presented in this paper can provide a theoretical basis for the traffic-induced evacuation decision making of large-scale activities.

개선된 Floor Field Model과 다른 피난시뮬레이션 모델의 비교 연구

본 연구는 보행자의 물리적 특성(크기, 모양, 자세 등)을 적용한 개선된 플로어 필드 모델(Floor field model; FFM)을 소개하고, 개선된 모델과 널리 알려진 다른 피난시뮬레이션 모델과의 비교를 통해 FFM의 한계점 파악 및 개선된 모델의 특징을 분석하고자 한다. FFM은 셀룰라 오토마타(Cellular automata)를 이용한 대표적 미시적 관점 보행 모델이지만 보행자의 크기, 모양, 자세 등의 물리적 특성을 세밀하게 반영하지 않는다. 이로 인해 보행자들 간의 충돌, 마찰 등의 현상을 모델링하기 어려우며 결과적으로 다른 모델들과 비교하였을 경우에 매우 짧은 대피 시간을 산출하고 있다. 본 연구는 물리적 현상을 반영할 수 있는 개선된 FFM을 제시하며, 개선된 모델과 기존 FFM, 시뮬렉스(Simulex), 패스파인더(Pathfinder) 등 다른 모델들과의 비교 실험을 수행하였다. 실험은 실제 캠퍼스 건물의 일부 공간을 대상으로 진행되었으며, 대피 인원의 변화에 따른 대피 양상의 비교와 각 출구별 대피 양상의 비교가 수행되었다. 이를 통해 FFM에서는 반영되지 않던 물리적 현상들이 개선된 모델에서는 상용 모델 수준으로 적용되는 점과 특히 시뮬렉스와 유사한 형태의 대피 양상을 보임을 확인하였다. In this study, we propose an improved Floor Field Model(FFM) that considers the physical characteristics of pedestrians, i.e., body size, shape, and posture. Also we analyse limits of FFM and features of improved model compared with existing evacuation simulation models. FFM is a typical microscopic pedestrian model using CA, but it does not reflect the physical characteristics of pedestrians. Because of this, FFM is difficult to modeling phenomena such as collision, friction between pedestrians. As a result, FFM calculates a very short evacuation time when compared with the other models. We performed a computational experiment to compare improved model with other models such as FFM, Simulex, Pathfinder in an actual campus building. We carried out a comparison of evacuation aspect according to the change in number of evacuees. Also we compared evacuation aspect by exit. Finally, we confirmed that improved model reflects physical phenomena which were not reflected in FFM. Especially, experimental results were very similar to the Simulex.

Consistent evolution in a pedestrian flow

In this paper, pedestrian evacuation considering different human behaviors is studied by using a cellular automaton (CA) model combined with the snowdrift game theory. The evacuees are divided into two types, i.e. cooperators and defectors, and two different human behaviors, herding behavior and independent behavior, are investigated. It is found from a large amount of numerical simulations that the ratios of the corresponding evacuee clusters are evolved to consistent states despite 11 typically different initial conditions, which may largely owe to self-organization effect. Moreover, an appropriate proportion of initial defectors who are of herding behavior, coupled with an appropriate proportion of initial defectors who are of rationally independent thinking, are two necessary factors for short evacuation time.

Selfishness- and Selflessness-based models of pedestrian room evacuation

Some pedestrian evacuation studies have employed game strategy to deal with moving conflicts involving two or three pedestrians. However, most of these have simply presented game strategies for pedestrians without analyzing the reasons why they choose to defect or cooperate. We believe that selfish and selfless behaviors are two main factors that should be considered in evacuation. In addition to these behaviors, human emotions such as sympathy and behaviors such as vying were also taken into account to investigate their impacts on pedestrians’ strategies. Moreover, an essential objective factor, the building design factor of door width was tested and analyzed. Experimental results showed that the sense of self leads to more defectors and a longer evacuation time. However, sympathy does some good, leading to more cooperators and a shorter evacuation time. Moreover, the exit door width is an essential factor of the evacuation efficiency. When the width was less than 6 cells in a rectangular room with a size greater than 50 × 50, the evacuation time greatly decreased when the width increased. However, this effect was less obvious when the width increased.

Role 2 military hospitals: results of a new trauma care concept on 170 casualties.

In recent military conflicts, military surgeons encounter more high-energy injuries associated with explosives. Advances in the field care and shorter evacuation time increased survival. However, casualties still incur severe injuries especially to the extremities. We present wound patterns, anatomical distribution and severity of injuries in a Role 2 hospital. Two years data have been retrospectively reviewed. Only explosives and firearms injuries were included in the study. Patient profile, admission details, mechanism of injury, AIS anatomical locations, ISS, surgical and medical treatments have been analyzed. Data revealed 170 male casualties. IEDs and GSW accounted for 133 (78%) and 37 (22%) casualties, respectively. An average of 1.8 IED and 1.2 GSW anatomical locations were exposed to injuries. Regardless of the mechanism, injuries were most commonly located in the extremities. IEDs caused significantly higher soft tissue injuries. Explosives do not necessarily cause more severe injuries than firearms. However, fragments create multiple, complicated soft tissue injuries which constitute more than half of the injuries. Timely wound debridement and excision of contaminated tissue are crucial to manage extremity soft tissue injuries. Casualty care should be assessed within the context of the capabilities present at a hospital and the cause, type and severity of the wounds. The NATO description of Role 2 care only requires an integrated surgical team for damage control surgery with limited diagnostic and infrastructural capabilities.

Simulation Study of Evacuation in High-rise Buildings

In this article, a vertical mixing evacuation model was presented, and some human factors had been considered, including the percentage of occupants using the elevators in relation to the located floors and the time they would wait for the elevator before move to stairs. Eight evacuation strategies for a 60-floor building were performed, taking a different combination of stairs and elevators. Results showed that the shortest evacuation time was gotten when a combination of elevators, staircases and refuge floors were used. And in most cases, if no appropriate information was provided, most elevator waiters would turn to stairs, which significantly reduced the efficiency of evacuation.

Optimization of Exit Design Based on Evacuation Model for Limited Visibility

In this paper, the evacuation strategies and the update rules for limited visibility are proposed. The formulas on single exit, double exits and four exits for low pedestrian density are deduced and showed; and the time ratio is 1: 0.71: 0.56. The simulation results show that for normal visibility, the exit should be designed in the middle of wall, which results in the shortest evacuation time. So each exit is designed in the middle of wall. Moreover, in the different exit cases the evacuation can be simulated very well using the proposed model; and the time ratio on single exit, double exits and four exits is 1: 0.68: 0.57,which is close to the theory value 1: 0.71: 0.56. More, the evacuation evolution of different pedestrian number is studied; and the results show that if no jamming, the time ratios of different pedestrian number accord with the theory value 1: 0.71: 0.56 mainly, which proves the correctness of evacuation model and theory analysis.