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- Frantzich, Håkan
(författare)
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En modell för dimensionering av förbindelser för utrymning utifrån funktionsbaserade krav
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report describes a model for the estimation of the time required to evacuate a building, by dividing the evacuation process into three phases: awareness, behaviour and response, and movement. The times required in each of these phases can be estimated separately and the sum then represents the total evacuation time. The time elapsed from the fire breaking out, to the discovery of the fire, is denoted the awareness time. When a person realises that something unusual is taking place, he will wish to obtain more information on the situation and will take steps to do this. The time which elapses before he actually starts to move towards the exit includes all the phases of behaviour which are associated with a fire situation, and is denoted the behaviour and response phase. The final phase is equivalent to the time required to leave the building on foot. This report presents data on walking speeds gathered from tests carried out within the framework of this project, and also gives an overview of equivalent information available in the literature. The exit paths studied were stairs, doors, horizontal passageways and windows. The information gathered and reviewed makes it possible to calculate the most suitable flow of people through various escape routes. In the section describing human behaviour in fire situations, results are presented from an investigation performed among fire officers in Sweden. This investigation is probably the first of its kind in the world. The fire officers estimated the time elapsed between the discovery of a fire and the onset of evacuation. This time was found to be dependent on the kind of premises in question and the manner in which the public were made aware of the fire. Evacuation alarms and messages providing clear information on the situation and on what the public is expected to do, led to short behaviour and response times. This is in good agreement with results from similar experiments found in the literature. Various strategies for evacuation are described, of which direct evacuation to the outdoors is one. Another strategy may be evacuation to another, safe, part of the building while the fire and rescue services fight the fire. Evacuation from the building can then take place from this safe place. This strategy is used, for example, in hospitals, where patients are moved from a burning ward to another ward in a neighbouring fire compartment. Complete evacuation can then take place from this ward.
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