Modelling the impact of sky-bridges on total evacuation for high-rise buildings

This study examines the impact of sky-bridges, as an egress component, on total evacuation of a high-rise building by using an evacuation model named Pathfinder. Five scenarios, with different combination of aspects such as height of the building, number of sky-bridges (and the subsequent inter-distance between them), and people allocation have been simulated. The comparison between the results from the simulations indicates that sky-bridges significantly shorten the total evacuation time if used by all occupants above or at each refuge floor. Furthermore the comparison between the scenarios with different heights and the same inter-distance between the sky-bridges shows that the total evacuation time is approximately the same, as the buildings are divided in zones containing equal number of floors. However the comparison between two buildings with the same height but different inter-distance between the sky-bridges point out that the total evacuation time increases with increased inter-distance between the sky-bridges and vice versa

Building evacuation: principles for the analysis of basic structures through dynamic flow networks

Purpose: The main purpose of this paper is to perform an analysis of the factors determining the architectural configuration of buildings for the mobility of people, using dynamic flow networks and considering group formation in the evacuation process. Design/methodology/approach: For a long time it has been considered that once an evacuation begins, movement on the evacuation route mainly obeys mechanical factors; people occupy the free spaces which lead to evacuation more or less automatically. However, recent research has emphasized the need to consider people’s behavior; one of the aspects considered in this work is group formation, with its significant influence on the evacuation process. In positions of convergence and their branches things become considerably more complicated; as well as occupants’ behavioral aspects other relevant factors such as the geometry of the premises are critical in this process. Authors propose models, in which nodes are strategically placed, besides taking into consideration aspects of behavior. Several cases are analyzed. Findings: The solution proposed in this paper is to analyze the problem through dynamic flow networks, using a macroscopic model in a deterministic environment in which the evolution of the quantities characterizing the problem at regular intervals is represented, obtaining a reasonably accurate and reliable understanding of the development of the evacuation. Originality/value: A precise model of evacuation routes, convergence points and branches which includes a consideration of occupants’ behavior is obtained using stochastic models with microscopic analysis, in which people’s behavior is considered individually, this solution is complex, difficult to apply with many occupants and in large enclosures, and also, this way does not lead to optimal solutions.Peer Reviewe

High-statistics pedestrian dynamics on stairways and their probabilistic fundamental diagrams

Staircases play an essential role in crowd dynamics, allowing pedestrians to flow across large multi-level public facilities such as transportation hubs, and office buildings. Achieving a robust understanding of pedestrian behavior in these facilities is a key societal necessity. What makes this an outstanding scientific challenge is the extreme randomness intrinsic to pedestrian behavior. Any quantitative understanding necessarily needs to be probabilistic, including average dynamics and fluctuations. In this work, we analyze data from an unprecedentedly high statistics year-long pedestrian tracking campaign, in which we anonymously collected millions of trajectories across a staircase within Eindhoven train station (NL). Made possible thanks to a state-of-the-art, faster than real-time, computer vision approach hinged on 3D depth imaging, and YOLOv7-based depth localization. We consider both free-stream conditions, i.e. pedestrians walking in undisturbed, and trafficked conditions, uni/bidirectional flows. We report the position vs density, considering the crowd as a 'compressible' physical medium. We show how pedestrians willingly opt to occupy fewer space than available, accepting a certain degree of compressibility. This is a non-trivial physical feature of pedestrian dynamics and we introduce a novel way to quantify this effect. As density increases, pedestrians strive to keep a minimum distance d = 0.6 m from the person in front of them. Finally, we establish first-of-kind fully resolved probabilistic fundamental diagrams, where we model the pedestrian walking velocity as a mixture of a slow and fast-paced component. Notably, averages and modes of velocity distribution turn out to be substantially different. Our results, including probabilistic parametrizations based on few variables, are key towards improved facility design and realistic simulation of pedestrians on staircases

The development of a full probabilistic risk assessment model for quantifying the life safety risk in buildings in case of fire

In het kader van dit onderzoek is een probabilistisch model ontwikkeld dat het brandveiligheidsniveau van een gebouwontwerp kan kwantificeren en dit berekende veiligheidsniveau kan evalueren aan de hand van een vooraf gedefinieerd aanvaardbaar risicocriterium. De ontwikkelde methodiek kan zowel prescriptieve als op prestatie-gebaseerde ontwerpmethoden objectiveren door rekening te houden met de onzekerheid van ontwerpparameters en de betrouwbaarheid van veiligheidssystemen. Het model bestaat uit zowel een deterministisch als een probabilistisch gedeelte. Het deterministische kader is opgebouwd uit verschillende deelmodellen om zowel de verspreiding van brand en rook, als de interactie met evacuerende personen te simuleren. Verschillende deelmodellen zijn ontwikkeld om het effect van geïmplementeerde veiligheidsmaatregelen zoals detectie, sprinklers , rook- en warmteafvoersystemen, enz. mee in rekening te brengen. Het probabilistische kader is opgebouwd uit modellering van responsoppervlakken, steekproeftechnieken en ontwerp van grenstoestanden. De methodiek maakt gebruik van deze technieken om de nodige rekenkracht te beperken. Het uiteindelijke resultaat wordt vertaald naar een kans op sterfte, een individueel risico en een groepsrisico. De grote meerwaarde van de ontwikkelde methodiek is dat het mogelijk wordt om verschillende ontwerpmethodieken objectief met elkaar te vergelijken en het positieve effect van verbeterde veiligheidstechnieken en redundantie mee in rekening te brengen in het eindresultaat

Analysis and Modeling of Pedestrian Walking Behaviors Involving Individuals with Disabilities

The objective of this dissertation was to study walking behaviors of pedestrian groups involving individuals with disabilities. To this end, large scale controlled walking experiments were conducted at Utah State University (USU) to examine walking behaviors in various walking facility types, such as passageway, right angle, oblique angle, queuing area, bottleneck, and stairs. Walking experiments were conducted over four days involving participants with and without disabilities. Automated video identification and semi-structured questionnaires were used to collect revealed and stated walking data. This study provided statistical analysis and models to study three different aspects of operational walking behaviors. Firstly, walking speed was examined as one of the most important behavioral variables. The differences in crowd walking speeds were carefully noted in analyzing the effects of adding individuals with disabilities and the impacts of different indoor walking facilities. Results showed that the presence of individuals with disabilities in a crowd significantly reduces the overall crowd speed. Statistical analysis also provided to compare walking speeds of pedestrian groups involving individuals with disabilities in different walking environments. Secondly, the dissertation proposed a framework to study the interactions of different pedestrian groups. Specifically, a mixed time headway distribution model was used to examine the time headway between followers and different leader types. In addition, the implications of interaction behaviors were studied based on the capacity of the queuing area behind the doorway. Results revealed that: (1) individuals with disabilities had significant effects on capacity reduction; (2) individuals with visual impairments and non-motorized ambulatory devices had the minimum capacity reduction effects in queuing area; and (2) individuals with motorized wheelchairs and individuals with mobility canes had the maximum capacity reduction effects in queuing area. Lastly, this study explored how a heterogeneous mix of pedestrians (including individuals with disabilities) perceive and evaluate operational performance of walking facilities. Both trajectory and survey data sources were used, and an ordered statistical approach was applied to analyze pedestrian perceptions. Results indicated that individuals with disabilities were less tolerant of extreme congested environments. Furthermore, analysis showed that the Level of Service (LOS) criteria provided in HCM does not follow the actual perceptions

Emergency Evacuation Software Model For Simulation Of Physical Changes

Public space such as schools, cinemas, shopping malls, etc. must have an emergency evacuation system in place. Such places are also required to follow certain regulations and protocols for emergency evacuation to assure the safety of their occupants inside from any unpredictable incident. For nearly two decades, companies/organizations are using simulation models/software for evacuation planning. Researchers are working on these software models to improve the efficiency using latest algorithms. This thesis focuses on creating a base software model of evacuation systems for 3D indoor environments to simulate physical changes such as retractable chairs, movable walls etc., to evaluate their effectiveness before committing to those changes. This research tries to address various flaws and shortcomings of previous software. We are using tools like Unity 3D and Autodesk Maya to simulate suggested changes. It provides planners as well as researchers a new perspective to work on new recommended physical changes to design public venues

Developing new techniques for modelling crowd movement

Vol 2 only - vol 1 missin

Engineering egress data considering pedestrians with reduced mobility

To quantify the evacuation process, evacuation practitioners use engineering egressdata describing the occupant movement characteristics. These data are typicallybased to young and fit populations. However, the movement abilities of occupantswho might be involved in evacuations are becoming more variable—with the buildingpopulations of today typically including increasing numbers of individuals: withimpairments or who are otherwise elderly or generally less mobile. Thus, there willbe an increasing proportion of building occupants with reduced ability to egress. Forsafe evacuation, there is therefore a need to provide valid engineering egress dataconsidering pedestrians with disabilities. Gwynne and Boyce recently compiled aseries of data sets related to the evacuation process to support practitioner activitiesin the chapter Engineering Data in the SFPE Handbook of Fire Protection Engineering.This paper supplements these data sets by providing information on and presentingdata obtained from additional research related to the premovement and horizontalmovement of participants with physical-, cognitive-, or age-related disabilities. Theaim is to provide an overview of currently available data sets related to, and keyfactors affecting the egress performance of, mixed ability populations which could beused to guide fire safety engineering decisions in the context of building design