Evacuation process simulation
Encyclopedia
Evacuation simulation is a method to determine evacuation
times for areas, buildings, or vessels. It is based on the simulation
of crowd
dynamics and pedestrian motion.
The distinction between buildings, ships, and vessels on the one hand and settlements and areas on the other hand is important for the simulation of evacuation processes. In the case of the evacuation of a whole district, the transport
phase (see emergency evacuation
) is usually covered by queueing models (see below).
s are based on mathematical models that resemble reality. The calculations are usually carried out using computers. Models are the specification of a certain theory. They can be classified according to the following criteria:
(Gershenfeld, 1999):
Simulations are not primarily methods for optimization
. To optimize the geometry of a building or the procedure with respect to evacuation time, a target function has to be specified and minimized. Accordingly, one or several variables must be identified which are subject to variation.
Queueing model
s belong to the macroscopic models which are based on the graph
ical representation of the geometry. The movement of the persons is represented as flow
on this graph
. Microscopic
models on the other hand are based on a detailed representation of geometry and population. If the individuals are autonomous and interact with each other, these models are called Multi-agent systems. Stochastic parameters
describe the agents' movement and decisions and represent influences not further specified or which cannot be quantified directly and have to be calibrated via comparison with empirical data. Analytic results are very hard to obtain for social systems. General models can be applied to the evacuation of buildings, aircraft, and ships alike.
Ship motion and/or abnormal floating position may decrease the ability to move. This influence has been investigated experimentally and can be taken into account by reduction factors.
The evacuation of a ship is divided into two separate phases: assembly phase and embarkation phase.
requires that aircraft have to be able to be evacuated within 90 seconds. This criterion has to be checked before approval of the aircraft.
The 90-second rule requires the demonstration that all passengers and crew members can safely abandon the aircraft cabin in less than 90 seconds, with half of the usable exits blocked, with the minimum illumination provided by floor proximity lighting, and a certain age-gender mix in the simulated occupants.
The rule was established in 1965 with 120 seconds, and has been evolving over the years to encompass the improvements in escape equipment, changes in cabin and seat material, and more complete and appropriate crew training.
Very recently, a meaningful move has modified the up to now classical approach with new exit types, new conditions to perform or assess evacuation demonstrations, etc, although some questions are still open. These capacities are completed in the regulations with a series of statements regarding additional interactions and limitations.
The unique objective of the demonstration is to show that the airplane can be evacuated in less than 90 seconds under the aforementioned conditions. So the demonstration provides only a benchmark for consistent evaluation, which allows for comparisons among diverse seating arrangements or modifications in existing airplanes. Obviously, the demonstration can not represent accident scenarios and is not intended for system optimization.
Emergency evacuation
Emergency evacuation is the immediate and rapid movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a bomb threat or fire to the large scale evacuation of a district because of a flood, bombardment or...
times for areas, buildings, or vessels. It is based on the simulation
Simulation
Simulation is the imitation of some real thing available, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system....
of crowd
Crowd
A crowd is a large and definable group of people, while "the crowd" is referred to as the so-called lower orders of people in general...
dynamics and pedestrian motion.
The distinction between buildings, ships, and vessels on the one hand and settlements and areas on the other hand is important for the simulation of evacuation processes. In the case of the evacuation of a whole district, the transport
Transport
Transport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...
phase (see emergency evacuation
Emergency evacuation
Emergency evacuation is the immediate and rapid movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a bomb threat or fire to the large scale evacuation of a district because of a flood, bombardment or...
) is usually covered by queueing models (see below).
Classification of models
SimulationSimulation
Simulation is the imitation of some real thing available, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system....
s are based on mathematical models that resemble reality. The calculations are usually carried out using computers. Models are the specification of a certain theory. They can be classified according to the following criteria:
(Gershenfeld, 1999):
| specific Specific Specific may refer to:* Specificity* Specific, a cure or therapy for a specific illnessLaw:* Specific deterrence, focussed on an individual* Specific finding, intermediate verdict used by a jury in determining the final verdict... |
-- | general General A general officer is an officer of high military rank, usually in the army, and in some nations, the air force. The term is widely used by many nations of the world, and when a country uses a different term, there is an equivalent title given.... |
| phenomenological Phenomenology (science) The term phenomenology in science is used to describe a body of knowledge that relates empirical observations of phenomena to each other, in a way that is consistent with fundamental theory, but is not directly derived from theory. For example, we find the following definition in the Concise... |
-- | first principles First principles In philosophy, a first principle is a basic, foundational proposition or assumption that cannot be deduced from any other proposition or assumption. In mathematics, first principles are referred to as axioms or postulates... |
| discrete Discrete Discrete in science is the opposite of continuous: something that is separate; distinct; individual.Discrete may refer to:*Discrete particle or quantum in physics, for example in quantum theory... |
-- | continuous |
| numeric | -- | analytic Analytical software Analytical software is software that is designed specifically for analysis and development of a particular environment or object.... |
| stochastic Stochastic Stochastic refers to systems whose behaviour is intrinsically non-deterministic. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac and E... |
-- | deterministic |
| quantitative Quantitative A quantitative property is one that exists in a range of magnitudes, and can therefore be measured with a number. Measurements of any particular quantitative property are expressed as a specific quantity, referred to as a unit, multiplied by a number. Examples of physical quantities are distance,... |
-- | qualitative |
| macroscopic Macroscopic The macroscopic scale is the length scale on which objects or processes are of a size which is measurable and observable by the naked eye.When applied to phenomena and abstract objects, the macroscopic scale describes existence in the world as we perceive it, often in contrast to experiences or... |
-- | microscopic Microscopic The microscopic scale is the scale of size or length used to describe objects smaller than those that can easily be seen by the naked eye and which require a lens or microscope to see them clearly.-History:... |
Simulations are not primarily methods for optimization
Optimization (mathematics)
In mathematics, computational science, or management science, mathematical optimization refers to the selection of a best element from some set of available alternatives....
. To optimize the geometry of a building or the procedure with respect to evacuation time, a target function has to be specified and minimized. Accordingly, one or several variables must be identified which are subject to variation.
Queueing model
Queueing model
In queueing theory, a queueing model is used to approximate a real queueing situation or system, so the queueing behaviour can be analysed mathematically...
s belong to the macroscopic models which are based on the graph
Graph (mathematics)
In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...
ical representation of the geometry. The movement of the persons is represented as flow
Flow network
In graph theory, a flow network is a directed graph where each edge has a capacity and each edge receives a flow. The amount of flow on an edge cannot exceed the capacity of the edge. Often in Operations Research, a directed graph is called a network, the vertices are called nodes and the edges are...
on this graph
Graph (mathematics)
In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...
. Microscopic
Microscopic
The microscopic scale is the scale of size or length used to describe objects smaller than those that can easily be seen by the naked eye and which require a lens or microscope to see them clearly.-History:...
models on the other hand are based on a detailed representation of geometry and population. If the individuals are autonomous and interact with each other, these models are called Multi-agent systems. Stochastic parameters
Stochastic modelling
This page is concerned with the stochastic modelling as applied to the insurance industry. For other stochastic modelling applications, please see Monte Carlo method and Stochastic asset models. For mathematical definition, please see Stochastic process....
describe the agents' movement and decisions and represent influences not further specified or which cannot be quantified directly and have to be calibrated via comparison with empirical data. Analytic results are very hard to obtain for social systems. General models can be applied to the evacuation of buildings, aircraft, and ships alike.
Simulation of evacuations
Buildings (train stations, sports stadia), ships, aircraft, and trains are similar concerning their evacuation: the persons are walking towards a safe area. In addition, persons might use slides or similar evacuation systems and for ships the lowering of life-boats.Ships
Four aspects are particular for ship evacuation:- Ratio of number of crew to number of passengers,
- Ship motion,
- Floating position
- The evacuation system (e.g., slides, life-boats).
Ship motion and/or abnormal floating position may decrease the ability to move. This influence has been investigated experimentally and can be taken into account by reduction factors.
The evacuation of a ship is divided into two separate phases: assembly phase and embarkation phase.
Aircraft
The Federal Aviation AdministrationFederal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
requires that aircraft have to be able to be evacuated within 90 seconds. This criterion has to be checked before approval of the aircraft.
The 90-second rule requires the demonstration that all passengers and crew members can safely abandon the aircraft cabin in less than 90 seconds, with half of the usable exits blocked, with the minimum illumination provided by floor proximity lighting, and a certain age-gender mix in the simulated occupants.
The rule was established in 1965 with 120 seconds, and has been evolving over the years to encompass the improvements in escape equipment, changes in cabin and seat material, and more complete and appropriate crew training.
Very recently, a meaningful move has modified the up to now classical approach with new exit types, new conditions to perform or assess evacuation demonstrations, etc, although some questions are still open. These capacities are completed in the regulations with a series of statements regarding additional interactions and limitations.
The unique objective of the demonstration is to show that the airplane can be evacuated in less than 90 seconds under the aforementioned conditions. So the demonstration provides only a benchmark for consistent evaluation, which allows for comparisons among diverse seating arrangements or modifications in existing airplanes. Obviously, the demonstration can not represent accident scenarios and is not intended for system optimization.
Literature
- A. Schadschneider, W. Klingsch, H. Klüpfel, T. Kretz, C. Rogsch, and A. Seyfried. Evacuation Dynamics: Empirical Results, Modeling and Applications. In R.A. Meyers, editor, Encyclopedia of Complexity and System Science. Springer, Berlin Heidelberg New York, 2009. (to be published in April 2009, available at arXiv:0802.1620v1).
External links
- Pedestrian and Evacuation Dynamics Wiki
- Pathfinder 2011 - Evacuation Simulation Software from Thunderhead Engineering
- EXODUS - evacuation modelling software, by the Fire Safety Engineering Group at the University of GreenwichUniversity of GreenwichThe University of Greenwich is a British university located in the London Borough of Greenwich, London, England. The main campus is located on the grounds of the Old Royal Naval College, a central location within the Maritime Greenwich UNESCO World Heritage Site.-History:The history of the...
, UK - Evacmod.net - Evacuation Modelling Portal
- TraffGo and PedGo Pedestrian simulation and evacuation dynamics
- PESOS and BYPASS Research projects "Evacuation of Passenger Ships" (University Duisburg-Essen, Germany)
- Simulation of Ship Evacuation at Germanischer Lloyd
- SURMA ship survivability simulation software (Includes evacuation simulation)
- The International Emergency Management Society
- Pedestrian escape panic simulation with the social force model (Eötvös University, Budapest, Hungary)
- Legion Pedestrian Simulation (Broadgate west London Fire Brigade case study)
- Online Pedestrian Dynamics Models
- SimWalk Software for evacuation simulation
- Enterprise Dynamics Plato Software for pedestrian and evacuation simulation