Evacuation Time Research Articles

A deep reinforcement learning traffic control model for Pedestrian and vehicle evacuation in the parking lot

As a necessary component of connecting the building interior and urban road network for evacuation, the evacuation of parking lots significantly impacts overall evacuation efficiency. However, existing emergency evacuation studies have ignored the control of pedestrian-vehicle mixed flow in parking lot environments, leading to underestimated evacuation time estimates. Therefore, this paper proposes a pedestrian-vehicle mixed-flow model to simulate the parking lot evacuation process at the microscopic level. Moreover, a deep reinforcement learning (DRL)-based evacuation control model is developed to control pedestrian evacuation speed. The numerical study shows that this control model can effectively reduce evacuation clearance time by 7.75 % when faced with enormous evacuation demands.

Evaluation of the Fire Impact of Cellulose-Based Indoor Building Finishing Materials According to Changes in Room Size Aspect Ratio

In modern society, the size of buildings tends to expand due to technological advances. However, while prioritizing performance design and specific building materials, fire research has fallen short of creating a comprehensive fire characteristic database for building materials. This study presents a plan for building a big data resource to evaluate the fire performance of cellulose-based flame retardant building finishing material in buildings of varying sizes. The three types of building finishing materials applied in this study are polyurethane foam, MDF, and cellulose-based building finishing materials. The variables were determined based on the floor area, and the change in floor area was calculated using the aspect ratio, a dimensionless number. Data analysis utilized the Fire Dynamics Simulator (FDS) to determine the time required to meet life safety standards for temperature, visibility, and Fractional Effective Dose (FED). The results confirm a correlation between the safe evacuation time (ASET) and increasing floor area. Additionally, the study demonstrates that cellulose-based flame-retardant building finishing material effectively maintains safe evacuation times even with increasing floor areas, as evidenced by increases of 41.0 s, 13.2 s, and 97.5 s in temperature, visibility, and FED, respectively.

The Effect of Herding Behavior on the Efficiency of Pedestrian Evacuation in Subway Stations

In the emergency evacuation of pedestrians in subway stations, most people do not know the correct evacuation routes and methods, and tend to follow others blindly, resulting in herding behavior. To study the process of pedestrian evacuation with herding behavior in subway stations, a cellular automata pedestrian evacuation model is established to simulate the pedestrian evacuation with herding behavior in subway stations, and the effects of the weight coefficients of the parameters in the model on the overall evacuation time and the distribution of people’s positions are investigated to quantify the effects of herding on the efficiency of the pedestrian evacuation and the movement behavior. The simulation results show that moderate (kC < 40) crowd behavior can play a beneficial role in reducing reaction time and guiding the direction of evacuation; on the contrary, excessive crowd behavior (kC > 40) will lead to an increase in evacuation time and a decrease in evacuation efficiency. The conclusions presented in this paper can help to improve the efficiency of pedestrian evacuation in emergencies and provide a theoretical basis and practical guidance for the management of safety evacuation in subway stations.

Self- and semi-supervised learning for evacuation time modeling within fire emergencies in nuclear power plants

Using neural networks for effective emergency response planning is essential to safeguard nuclear power plants and their surroundings swiftly and accurately during fire emergencies. However, achieving precise training of neural networks for fire evacuation modeling necessitates the collection of labeled data encompassing a variety of fire scenarios and their corresponding evacuation times. The acquisition of this labeled training dataset involves direct engagement in experimental simulations of evacuation times for diverse fire scenarios, accomplished through the application of the consolidated fire and smoke transport (CFAST) simulator. However, the endeavor to amass a diverse pool of labeled data imposes significant time and financial costs. To overcome this challenge, we propose using self- and semi-supervised learning to construct a metamodel that approximates the simulator and to improve the ability of neural networks that accurately predicts evacuation times even in situations with limited labeled data. The effectiveness of our proposed framework is demonstrated through the experimental results conducted on CFAST datasets, thus emphasizing its potential to develop nuclear safety guidelines based on neural networks.

Improvement Project on Timely Fire Evacuation for Patients under Hemodialysis

<p>因醫院高樓化、電氣配管複雜及病人受限於透析管路連接著機器易導致逃生困難，單位於2020年8月進行火災撤退演練，撤退時間為28分鐘17秒，高於消防署規定的21分鐘。故成立專案小組進行改善，分析確立問題為沒有參與過火災緊急應變撤退實際演練、撤退逃生路線標示不清、衛教指導後未確實評值病人的了解程度、相關衛教指導工具不足。執行期自2020年9月1日至2021年1月31日，為期5個月，依計劃期、執行期及評值期三階段進行，介入措施包含舉辦火災緊急應變撤退實際演練、製作撤退動線夜光引導標示、規範火災緊急應變撤退認知及技能稽核標準、製作火災緊急應變撤退小卡、衛教單張、教學影片及透析管路分離作業流程。專案實施後，病人對火災緊急應變撤退的認知由改善前的42.0%提升至改善後的88.4%，而撤退技能由改善前的38.9%提升至改善後的88.0%。撤退時間亦由28分鐘17秒縮短為19分鐘50秒。使病人在火災發生時，更有助於確保自身生命安全。</p> <p> </p><p>Difficulty in evaluation is considered due to the high-rise building of the hospital, the complicated electrical piping, and the fact that patients during hemodialysis are limited by the dialysis machines. A fire drill was conducted in August 2020, and the evacuation time was 28 minutes and 17 seconds. It is higher than the 21 minutes stipulated by the fire department. Therefore, a task force was formed to make improvements. After analyzation, we found several problems to be solved. First of all, patients had not participated in actual fire evacuation drill. Second, the evacuation routes were not clearly marked. Third, patients’ understanding was not adequately evaluated after our health education guidance. Fourth, the relevant health education guidance tools were insufficient. The implementation period is from September 1, 2020 to January 31, 2021, for a period of 5 months, in three stages: planning period, implementation period and evaluation period. Therefore, improvement measures was conducted, including holding actual fire drill with emergency evacuation, making luminous evacuation sign for escape routes, regulating auditing standards of cognitions and skills for evacuation, making emergency evacuation photocards, health education guidance leaflets and videos, and establishing operationg procedures of dialysis equipment separation. After the implementation of the project, the cognition improvement of patients about the emergency evacuation of fire was from 42.0% to 88.4%, and the skills of evacuation was from 38.9% to 88.0%. Furthermore, the evacuation time shortened from 28 minutes and 17 seconds to 19 minutes and 50 seconds. Eventually, it is more helpful for patients to ensure their own safety in the event of a fire.</p> <p> </p>

Evacuation safety effects of a lightweight elevator-type evacuation device using carbon material: Focus on plantar pressure and muscle strength.

Elevator-type evacuation devices have proven to be feasible in high-rise buildings through studies on safety performance and evacuation time. However, there is a lack of research on safety using biosignal analysis in the elderly population. A carbon material is used in this study to reduce the weight of an evacuation elevator. The impact on the human body is evaluated by conducting a satisfaction survey involving elderly and youth groups and quantitatively analyzing biological signals, including electromyography (EMG) and plantar pressure, during five repeated uses of the proposed device. The study involves 12 healthy adults in their 20s and 20 elderly individuals with no experience in using an evacuation elevator. The EMG and left and right plantar pressures are analyzed to evaluate the physical factors affected by repeated use. The experiment results showed that the normalization of EMG to maximum voluntary contraction showed a significant decrease with repeated use, especially in the right tibialis anterior muscle. Moreover, plantar pressure shows a significant difference, which decreased with repetition, and the left and right balance gradually tilted to the left. This suggests that with more repeated use, muscle tension decreases owing to adaptation, resulting in lower muscle activity and plantar pressure. Particularly, the tibialis anterior muscle experiences significant muscle activity, indicating increased load, but without any apparent danger. In the future, it will be necessary to evaluate elevators for disabled individuals.

재난안전관리체계 평가모형을 활용한 다중이용시설 안전관리 사례 연구

This study was conducted on the safety management of multi-use facilities using a disaster safety management system evaluation model, focusing on the case of Company A. Sports facilities within multi-use facilities are used by an unspecified number of people and require quick judgment and initial response from safety managers in the event of an emergency. In the event of an emergency such as a fire, it is important to respond to the delay in evacuation time for users of sports facilities on the top floor. The building managed by Company A has facilities such as a swimming pool, fitness center, sauna, indoor golf course, and yoga𐄁pilates room located on the top floor. We analyzed Company A's case of sports facilities in a building that is both a complex building and a multi-use facility. The building in question is located in Seoul, and the safety management case of Company A was studied in the following order building safety organization and system establishment, safety management capabilities, safety management activities, education and training, and evaluation feedback. Through this, we studied key management issues and vulnerabilities requiring safety in multi-use facilities, as well as cases of fire drills and evacuation measures to prepare for disaster occurrences, and focused on the safety management system of multi-use facilities and conducted research on sports facilities within multi-use facilities safety and improvement measures were derived. By applying Company A's safety management best practices to the research model, the company's safety management can be effectively analyzed and examined. Through this study, we would like to make suggestions so that safety managers of buildings with sports facilities in multi-use facilities can use them as a reference.

Monte Carlo Analysis for Evacuation in Multipurpose Event Spaces

This paper addresses the evacuation of people from multipurpose halls and introduces an innovative approach that uses a probabilistic model, specifically the Monte Carlo method, to analyse iterative evacuation processes. The aim is to explore how this modern technology can contribute to the development of effective and safe evacuation plans for mass events. The Monte Carlo method was applied to a specific example of a multipurpose hall that offers different configurations for events such as sports matches, concerts, or performances. The evacuation of people was analysed for two configurations: a hockey match with a capacity of 9500 people and a concert with a capacity of 11,000 people. In both cases, the total evacuation of people from the hall was analysed, and the evacuation time was evaluated when two parameters were changed: speed of movement and preference for door selection. The results of the simulations can provide valuable information for the design of effective safety measures in multipurpose halls and other similar multipurpose venues. This innovative approach to evacuation analysis allows for a comprehensive assessment of the evacuation process, identification of critical areas, and verification of the layout of the space.

Assessment of urban underground spaces inundation during extreme rainfall events.

As urbanization progresses and the impacts of climate change become more pronounced, urban flooding has emerged as a critical challenge for resilient cities, particularly concerning urban underground spaces where flooding can lead to significant loss of life and property. Drawing upon a comprehensive review of global research on underground space flood simulation and evacuation, this paper undertakes the modelling of inundation in a substantial underground area during the extraordinary rainfall event on 7 September 2023, in Shenzhen, China. Specifically, it introduces a two-step method to simulate the coupled surface-underground inundation process with high accuracy. The study simulates the inflow processes in three types of underground spaces: parking lots, metro stations, and underpasses. Utilizing the specific force per unit width evaluation, the research examines how varying flood barrier heights influence evacuation time and inundation risk. Subsequently, the paper proposes corresponding evacuation strategies based on the obtained findings. By highlighting the vulnerability of urban underground spaces to flooding, the study underscores the urgent need for further research in this domain.

Understanding Tsunami Evacuation via a Social Force Model While Considering Stress Levels Using Agent-Based Modelling

Given massive events, such as demonstrations in coastal cities exposed to tsunamigenic earthquakes, it is essential to explore pedestrian motion methods to help at-risk coastal communities and stakeholders understand the current issues they face to enhance disaster preparedness. This research targets SDG 11 Sustainable Cities and Communities. It strengthens resilience in coastal areas by implementing a social force model using a microscopic agent-based model to assess the impact of human behaviour on evacuation performance by introducing evacuation stress levels due to a tsunami triggered in central Chile. Two scenarios with two environments and three crowd sizes are implemented in NetLogo. In Scenario 1, pedestrians walk at a relaxed velocity. In Scenario 2, tsunami evacuation stress is incorporated, resulting in pedestrians walking at a running velocity, taking, on average, four times less time to evacuate. We explored more realistic settings by considering the internal susceptibility of each agent to spread tsunami evacuation stress among other evacuees. Results from Scenario 2 show that internal susceptibility effects almost double the mean evacuation time for 200 agents. Findings suggest a trade-off between realism and the minimization of evacuation time. This research is considered a first step toward including stress in tsunami evacuations for sustainable evacuation planning.

Prediction of the in-plane permeability and air evacuation time of fiber-placed thermoplastic composite preforms with engineered intertape channels

The two main void removal mechanisms during vacuum-bag-only (VBO) consolidation of thermoplastic composites are through-thickness diffusion and in-plane air evacuation. The automated fiber placement (AFP) process allows for the creation of preforms with an engineered intertape channel network by deliberately introducing spacing between the tapes that can facilitate air evacuation during the VBO consolidation. However, it is unclear what dimensions of the intertape channels allow for effective in-plane air evacuation. The current research presents a predictive simulation tool to optimize the intertape channel dimensions for effective in-plane air evacuation. An analytical method is developed to calculate the in-plane permeability tensors of the composite preform with uniform intertape channel dimensions. In addition, a more elaborate mesoscale method is developed that estimates the in-plane permeability tensor of the engineered intertape channel network based on the distributions in intertape channel dimensions. Finally, a finite difference model is implemented to calculate the time required for air evacuation as a function of the in-plane permeability tensors of the preform and its in-plane dimensions. The results from the models indicated that in-plane air evacuation through the engineered intertape channel network is quick, and it takes only a few minutes to evacuate 99% of the air from large preforms like fuselage panels.

A stochastic optimization model for patient evacuation from health care facilities during hurricanes

We propose a rigorous modeling and methodological effort that integrates statistical implementation of hydrology models in predicting inland and coastal flood scenarios due to hurricanes and a scenario-based stochastic integer programming model which suggests resource and staging area decisions in the first stage and the evacuation decisions in the second stage. This novel study combines physics-based flood prediction models and stochastic optimization for large-scale multi-facility coordination of hospital and nursing home evacuations before impending hurricanes. The optimization model considers scenario-dependent evacuation demand, transport vehicles with varying capacities, and both critical and non-critical patients. Utilizing Hurricane Harvey of 2017 as a case study and actual healthcare facility locations in southeast Texas, we explore various evacuation policies, demonstrating the impact of routing strategies, staging area decisions, flood thresholds, and receiving facility capacities on evacuation outcomes. One of the findings is that choosing staging area(s) and deploying evacuation vehicles optimally considering the uncertainty of the hurricane’s path at the time of decision making could have significant effect on the total cost of the operation and evacuation time experienced by the evacuees. We also show the non-negligible value of the scenario-based staging and routing solution conservatively calculated in relation to a single scenario solution using the concept of value of stochastic solution.

COMPARATIVE STUDY OF EGRESS TIME ON BRAWIJAYA STADIUM AND GOR JAYABAYA KEDIRI

Egress time in stadiums and sports buildings is one of the important things to consider in providing safety and tranquility for the audience in the building. The purpose of accessibility systems and adequate evacuation circulation planning in sports buildings is to provide evacuation routes that are easily accessible to spectators and minimize crowds and accumulation of people at the exit. This study aims to determine the most effective evacuation time at the Brawijaya Stadium and GOR Jayabaya in Kediri and the difference in the evacuation of spectators in a fire situation in open and closed buildings. This research uses simulation experimental research methods using Pathfinder and Pyrosim applications to find the most effective evacuation time in each building. The final results show that the addition of a radial gangway, the addition of exit doors, and the improvement of circulation flow effectively reduce the length of evacuation time in both buildings. At the Brawijaya Stadium, the evacuation time was 6 minutes and 59 seconds. GOR Jayabaya requires an evacuation time of 6 minutes and 56 seconds. In addition, there are differences in the distribution of smoke and fire in open and closed buildings. Keywords: Egress Time; Evacuation Time; Evacuation Circulation.

Surface Nanostructures Promote Droplet Splash on Hot Substrates.

Splash, one of the most visually apparent droplet dynamics, can manifest on any surface above a certain impact velocity, regardless of surface wettability. Previous studies demonstrate that elevating the substrate temperature can suppress droplet splash, which is unfavorable for many practical applications, such as spray cooling and combustion. Here, we report that the suppression effect of substrate temperature on splash is nullified by utilizing surfaces with nanostructures. By manipulating air evacuation time through surface nanostructures, we have identified a pathway for precise control over the splash threshold and the ability to tailor the dependence of the splash onset on surface temperature. We further propose a theoretical criterion to determine different splash regimes by considering the competition between air evacuation and the development of flow instabilities. Our findings underscore the crucial role of nanostructures in splash dynamics, offering valuable insights for the control of splash in various industrial scenarios.

Optimal time interval of information update using by exit-choice system to improve pedestrian evacuation efficiency

In the case of emergency evacuation of large places, the rapid evacuation of pedestrians has always been a matter of great concern. However, research on pre-movement behavior and decision-making fatigue behavior of pedestrians in emergency evacuation situations is limited. In order to study how to improve evacuation efficiency under the introduction of exit-choice system, this paper uses the cellular automata model to simulate different exit arrangements and exit numbers at different time intervals of information update by the system. It is found that there is an optimal time interval of information update when three exits of a room have different widths, and the evacuation time significantly reduces compared to real-time update. The potential mechanism of the optimal time interval of information update is that the evacuees can be reasonably allocated to each exit, so that the passage capacity of each exit can be maximized, and the evacuation time is significantly reduced. Sensitivity analysis shows that the change of exit location has an important influence on the evacuation time. The different pre-movement times of pedestrians have a certain degree of influence on the evacuation time of real-time update. The different distance parameters and flow parameters had a significant impact on the evacuation time in the real-time update case.

Dynamics characteristic of pedestrians’ particular overtaking behavior based on an improved social force model

The overtaking behavior of individuals under anxious panic is a major causative factor of crowded trampling accidents. In order to simulate the overtaking behavior of individuals experiencing anxiety and panic in a single-exit room within a normal pedestrian flow, an improved social force model is proposed to simulate crowd movement at local medium and high density through introducing the bypass overtaking mechanism, the side overtaking mechanism, and the side avoidance mechanism generated by association. The numerical simulation verifies the model’s validity. The effect of the size and number of overtaking individuals on the pedestrian flow are explored. The results show that the new model can simultaneously reproduce a variety of overtaking behaviors and their associated behaviors in line with reality. The larger size of the overtaking individuals are, the easier it is to produce overtaking behaviors and the more difficult it is to overtake. With the increase of the number of overtaking individuals, the evacuation time becomes longer, but there is no linear relationship between them. When the initial pedestrian density is 0.37ped/m2, with time evolution, the appearance frequency of local density greater than 0.8ped/m2 suddenly increases, and the comfort and safety of pedestrian movement decreases. The results of this paper can enrich the social force simulation model of pedestrian flow and provide a theoretical guidance for the evacuation of pedestrian flow with a few overtaking individuals in the room.

Dynamic design of hazardous chemical storage in high-rise R&D building based on numerical simulation

With the increasing demand for research on hazardous chemicals in high-rise research and development (R&D) buildings, the use of a large number of flammable chemicals increases the fire risk significantly. Therefore, the research on the storage of hazardous chemicals in high-rise R&D buildings becomes more and more important. This paper presents a maximum dynamic design method for hazardous chemical storage. A set of fire risk indicators has been established in the research, including temperature, carbon monoxide concentration, and visibility. The representative hazardous chemicals are selected through the investigation of the distribution and quantity of hazardous chemicals. Through numerical simulation of high-rise building fire with different stocks of dangerous chemicals and evacuation simulation of different fire floors, the time when the risk factors of fire occurrence reach the critical threshold of human body (ASET) and the necessary time for human evacuation (RSET) are obtained. By adjusting the amount of hazardous chemicals stored, the time to reach the hazardous critical threshold (RSET) and the time to evacuate (ASET) are changed accordingly. When RSET < ASET, the storage capacity of hazardous chemicals in the high-rise R&D building meets the target requirements. In the case study, ethanol was selected as the representative substance, and numerical simulation and example calculation were carried out on a 16-story R&D building. The amount of ethanol stored on each floor was calculated. Among them, the eighth layer has the largest ethanol storage capacity (1.81 L/m2) and the ninth layer has the smallest ethanol storage capacity (0.89 L/m2).

Pedestrian evacuations with imitation of cooperative behavior.

We analyze the dynamics of room evacuation for mixed populations that include both competitive and cooperative individuals through numerical simulations using the social force model. Cooperative agents represent well-trained individuals who know how to behave in order to reduce risks within high-density crowds. We consider that competitive agents can imitate cooperative behavior when they are in close proximity to cooperators. We study the effects of the imitation of cooperative behavior on the duration and safety of evacuations, analyzing evacuation time and other quantities of interest for varying parameters such as the proportions of mixing, the aspect ratio of the room, and the parameters characterizing individual behaviors. Our main findings reveal that the addition of a relatively small number of cooperative agents into a crowd can reduce evacuation time and the density near the exit door, making the evacuation faster and safer despite an increase in the total number of agents. In particular, for long spaces such as corridors, a small number of added cooperative agents can significantly facilitate the evacuation process. We compare our results with those of systems without imitation and also study the general role of cooperation, providing further analysis for homogeneous populations. Our main conclusions emphasize the potential relevance of training people how to behave in high-density crowds.

An evacuation model considering pedestrian fall behavior in an inclined passenger ship

Passenger ships are likely to be inclined during and after accidents, which is a vital factor that affects pedestrian behaviors and crowd dynamics in the evacuation process. On a significantly inclined ship, pedestrian fall behavior becomes more complex, increasing the risk of stampedes. Nevertheless, this type of evacuation has rarely been investigated. In this study, an extended cellular automata (CA) model that meets the inherent characteristics of passenger ship evacuations is constructed. The inclination force and self-adjusting force are incorporated into the model to evaluate the balance mechanism of pedestrians, while a method to calculate the probability of pedestrians falling down is established by considering the ship heeling angle and pedestrian heterogeneity. Further, the state of the pedestrians after falling to the ground is analyzed. A hazard field is introduced to describe the interaction between normal pedestrians and fallen pedestrians. The simulation results show that deaths occur when the ship heeling angle is greater than 20° and the crowd is evacuated successfully and fastest at the ship heeling angle of 5°, even better than on the flat ground. The greater the ship heeling angle, the more likely pedestrians are to fall over, and the earlier the first death occurs, thereby resulting in longer evacuation time and increased fatalities. The heterogeneity of passengers has considerable effects on the effectiveness of the ship evacuation, with a greater proportion of strong-resistance pedestrians reducing the crowd death and fall risks, even though the influence of crowd constitution on crowd evacuation time is insignificant. The death toll and evacuation time increased with the initial number of pedestrians aboard the ship. This study is beneficial in terms of understanding the evolution mechanism of evacuation dynamics and developing effective strategies for crowd emergency management on large passenger vessels.

Integrated assessment of bioaerosol dispersion patterns and infection risk in a typical urban environment: Implications for urban biosecurity management

Exposure to bioaerosols in high-density urban environments will pose a severe threat to human life and health and present significant challenges to the sustainability and resilience of cities. In this study, the aerodynamic dispersion patterns of bioaerosols at two release locations (open and dense areas) under both thermal conditions in Zhongguancun, Beijing, are investigated. By coupling a dose-response model and an improved cellular automaton, the infection risk within exposed populations was assessed, and emergency evacuation strategies for distinct populations in high-risk areas were devised. This study reveals that bioaerosol distribution is notably influenced by factors such as thermal conditions, release locations and pedestrian height. Bioaerosol concentration above the release source decreases with increasing pedestrian height at two release locations. Under the same exposure time, the infection probability of different groups in this area declines with pedestrian height increases, with adult males having the highest and elderly females having the lowest probability. Thermal conditions and building layout near the release source were second only to exposure time in influencing infection probability and evacuation path. Proximity to the release source indicates a high infection probability but a short evacuation distance to safe areas, while downstream areas exhibit lower infection probability but require longer evacuation distances. The layout of buildings near the release source has the most significant effect on evacuation time. Evacuation for high-risk populations should be prioritized upstream or either side of the mainstream. This study aims to mitigate potential biological threats, address challenges in enhancing urban biosecurity management, and enable sustainable urban development.