Ändrat gångavstånd till en utrymningsväg – En analys av vilka faktorer som bör tas i beaktande vid dimensionering

Sammanfattning: The allowed travel distance has probably not been determined scientifically. Yet it indirectly takes a number of factors into account and should therefore not only be seen as a distance that takes a certain time to walk, but also as a certain level of safety. Longer travel distances do extend the walking time but it also makes it possible for a series of factors to increase the risk. The factors that have been identified in this thesis are linked to complexity, number of occupants, possibility for a fire to occur, possibility to get blocked by the fire and operation abilities for the fire brigade. Higher complexity mainly causes a longer detection time and pre-movement time since it can be difficult to directly see the fire and know in which direction the movement should be done. The results of the thesis presented an increased risk of being subjected to critical conditions of several thousand percent for a very complex, as compared to a low complex, geometry. It was also shown that more occupants increase the risk with almost 300 %, due to the fact that occupants tend to go to a well-known exit. Even though a bigger building with higher possibility for a fire did not caused an increased risk, a combination of all factors led to an increased risk by almost 2 500 %. The possibility to get blocked by a fire and operation abilities for the fire brigade was only evaluated qualitatively, but the conclusions of the thesis was that all factors need to be considered when a longer travel distance are to be applied. It was also concluded that more research is necessary within the area.