The Development Of a Scenario Independent Method for Evaluating the Evacuation
Complexity of a Building
Hongjun Jiang
2011
Abstract
Over the past two decades, more than 30 evacuation models have been developed
to reproduce people’s movement patterns in evacuation. However, evacuation
models cannot assess whether one building is better than another in regards to
evacuation wayfinding.
There exist techniques that attempt to compare different buildings
for evacuation complexity. However, these graph measures are primarily
used to measure the relative accessibility of different locations in a
spatial system and were not generated for the purpose of comparing the
complexity of different buildings. Currently only one method exists,
Donegan’s method [DT98] [PD96] [DT99], which can be applied to compare
building for evacuation ability. However, this technique is severely
limited to specific building layouts and only considers connectivity.
Taking the Donegan’s method as a first step, this thesis extends this
algorithm to obtain a new Distance Graph Method, which
considers travel distance as well as being able to be applied to graphs
with circuits. Then a further building complexity measures is presented,
the Global Complexity (PAT) method. This is shown to be a valid
measure which considers additional important factors such as wayfinding
time, travel distance and the areas of compartments.
The Distance Graph Method and Global Complexity (PAT)
methods are based on a room graph representation which does not have the
descriptive power to describe the actual routes taken during the
wayfinding process. To resolve this drawback a further method is
presented which utilises a ‘route-based graph’ that has the ability to
represent the real route that an evacuee will take during the wayfinding
process.
Furthermore the Distance Graph Method and Global
Complexity (PAT) methods assume a “worst state” calculation for the
nodal information. This means for buildings with more than one exit
these methods calculate a global building complexity according to a
mathematical formula, which considers all exits separately. To address
these problems, the final method, Complexity Time Measure, is
presented, which is based around a number of wayfinding behaviour rules
over a ‘route-based graph’ representation. This addresses the question:
‘If an occupant is positioned at a random location within a
building, on average how long does the occupant need to spend to find an
available exit?’ Hence, provides a means to compare complex
buildings, with circuits, in relation to evacuation capability.
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