S. Gwynne

A review of the methodologies used in the computer simulation of evacuation from the built environment

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.

Modelling occupant interaction with fire conditions using the buildingEXODUS evacuation model

When evacuating through fire environments, the presence of smoke may not only have a physiological impact on the evacuees but may also lead occupants to adapt their evacuation strategy through the adoption of another exit. This paper attempts to introduce this type of adaptive behaviour within the buildingEXODUS evacuation model through enabling occupants to make decisions concerning the selection of the most viable available exit during an evacuation involving fire. The development of this adaptive behaviour requires the introduction of several new capabilities namely, the representation of the occupants’ familiarity with the structure, the behaviour of an occupant that is engulfed in smoke and the behaviour of an occupant that is faced with a smoke barrier. The appropriateness of the redirection decision is dependent upon behavioural data gathered from real fire incidents (in the UK and USA) that is used to construct the redirection probabilities. The implementation is shown to provide a more complex and arguably more realistic representation of this behaviour than that provided previously.

A review of the methodologies used in evacuation modelling

Computer based analysis of evacuation can be performed using one of three different approaches, namely optimization, simulation and 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 that are available has led to the development of some 22 different evacuation models. This review 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.

An investigation of the aspects of occupant behavior required for evacuation modeling

This article examines occupant behavior exhibited during evacuation conditions. This is based on a review of a wide range of published literature concerned with evacuation. Factors influencing evacuation performance can be categorized into four broad areas, namely, configurational, environmental, procedural, and, most importantly, behavioral. The contributory factors associated with each of the four influencing categories are examined in detail and it is suggested that these factors should be represented within evacuation models. Language: en

The Collection and Analysis of Pre-evacuation Times Derived from Evacuation Trials and Their Application to Evacuation Modelling

This paper presents data relating to occupant pre-evacuation times from university and hospital outpatient facilities. Although the two occupancies are entirely different, they do employ relatively similar procedures: members of staff sweep areas to encourage individuals to evacuate.However the manner in which the dependent population reacts to these procedures is quite different. In the hospital case, the patients only evacuated once a member of the nursing staff had instructed them to do so, while in the university evacuation, the students were less dependent upon the actions of the staff, with over 50% of them evacuating with no prior prompting. In addition, the student pre-evacuation time was found to be dependent on their level of engagement in various activities.

The Need for Behavioral Theory in Evacuation Modeling

This paper posits the need for a complete, comprehensive conceptual model about human behavior in fire evacuations. This would be of intrinsic value to improve training, education, and future data collection efforts, but would also allow for a complete behavioral representation to be embedded within simulation tools. This paper begins by discussing the current, separate theories or “behavioral facts” extracted from research on evacuations from building fires. Then, the paper discusses the methods used by current computer evacuation models to simulate these “behavioral facts” and the limitations of these methods. Last, the paper argues for the inclusion of a comprehensive behavioral conceptual model in computer evacuation models, specifically by highlighting the benefits of behavioral theory for evacuation models and providing examples of social theories used to predict whether people will evacuate from disasters in communities.

A systematic comparison of model predictions produced by the buildingExodus evacuation model and the Tsukuba Pavilion evacuation data

In this article, the buildingEXODUS (V1.1) evacuation model is described and discussed and attempts at qualitative and quantitative model validation are presented. The data set used for the validation is the Tsukuba pavilion evacuation data. This data set is of particular interest as the evacuation was influenced by external conditions, namely inclement weather. As part of the validation exercise, the sensitivity of the buildingEXODUS predictions to a range of variables and conditions is examined, including: exit flow capacity, occupant response times, and the impact of external conditions on the developing evacuation. The buildingEXODUS evacuation model was found to produce good qualitative and quantitative agreement with the experimental data.

Representing the Influence of Signage on Evacuation Behavior within an Evacuation Model

Occupant interaction with signage systems is being introduced into evacuation simulations through the newly developed concept of the Visibility Catchment Area or VCA. In this article, we describe the concept of VCA and how it has been extended to incorporate the presence of physical obstructions and termination distance. The VCA concept is then linked to a prototype behavior model intended to represent the occupants interaction with the signage system. The functionality and performance of the newly developed model is then demonstrated through the simulation of various evacuation scenarios within a hypothetical supermarket layout.

Analysing the Evacuation Procedures Employed on a Thames Passenger Boat Using the maritimeEXODUS Evacuation Model

On the 19 June 2001, a Thames passenger/tour boat underwent several evacuation trials. This work was conducted in order to collect data for the validation of marine-based computer models. The trials involved 111 participants who were distributed throughout the vessel. The boat had two decks and two points of exit from the lower deck placed on either side of the craft, forward and aft. The boat had a twin set of staircases towards the rear of the craft, just forward of the rear exits. maritimeEXODUS was used to simulate the full-scale evacuation trials conducted. The simulation times generated were compared against the original results and categorised according to the exit point availability. The predictions closely approximate the original results, differing by an average of 6.6% across the comparisons, with numerous qualitative similarities between the predictions and experimental results. The maritimeEXODUS evacuation model was then used to examine the evacuation procedure currently employed on the vessel. This was found to have potential to produce long evacuation times. maritimeEXODUS was used to suggest modifications to the mustering procedures. These theoretical results suggest that it is possible to significantly reduce evacuation times.

Examining the effect of exit separation on aircraft evacuation performance during 90-second certification trials using evacuation modelling techniques

This paper examines the influence of exit separation, exit availability and seating configuration on aircraft evacuation efficiency and evacuation time. The purpose of this analysis is to explore how these parameters influence the 60-foot exit separation requirement found in aircraft certification rules. The analysis makes use of the airEXODUS evacuation model and is based on a typical wide-body aircraft cabin section involving two pairs of Type-A exits located at either end of the section with a maximum permissible loading of 220 passengers located between the exits. The analysis reveals that there is a complex relationship between exit separation and evacuation efficiency. A main finding of this work is that for the cabin section examined, with a maximum passenger load of 220 and under certification conditions, exit separations up to 170ft will result in approximately constant total evacuation times and average personal evacuation times. This practical exit separation threshold is decreased to 114ft if another combination of exits is selected. While other factors must also be considered when determining maximum allowable exit separations, these results suggest it is not possible to mandate a maximum exit separation without taking into consideration exit type, exit availability and aircraft configuration.