Model Name: EXIT89
Version: Version 1.01
Classification: Evacuation Model
Very Short Description: An evacuation model designed
to handle the evacuation of
a large population of individuals from a high-rise
building.
Modeler(s), Organization(s): Rita
F. Fahy, National Fire Protection Association
User’s Guide:
User's Manual, EXIT89 v 1.01, An Evacuation Model
for
High-Rise Buildings
Technical References:
(The most recent and complete description of the
model is
the author's dissertation, completed in May, 2000.)
R.F. Fahy, "EXIT89 - An Evacuation
Model for High-Rise
Buildings -- Model Description and Example
Applications," Proceedings of the Fourth
International
Symposium, T. Kashiwagi, Editor, International
Association
for Fire Safety Science, 1994, pp. 657-668.
R.F. Fahy, "EXIT89 - An Evacuation Model
for High-Rise
Buildings," Proceedings - Interflam '93,
Interscience
Communications Ltd., London, 1993, pp. 519-528.
R.F. Fahy, "EXIT89: An Evacuation Model for
High-Rise
Buildings," Proceedings of the Third International
Symposium, G. Cox and B. Langford, Editors, International
Association for Fire Safety Science, 1991, pp.
815-823.
R.F. Fahy, "EXIT89 - An Evacuation Model
for High-Rise
Buildings," Proceedings of the 11th Joint
Panel Meeting of
the UJNR Panel on Fire Research and Safety, NISTIR
4449, National Institute of Standards and Technology,
Gaithersburg MD, October 1990, pp. 306-311.
Validation References: (The most recent verification
exercises can be found in the
author's dissertation, completed in May, 2000.
The results
will be published in the near future.)
R.F. Fahy, "A Practical Example of an Evacuation
Model
for Complex Spaces," Proceedings of the First
International Symposium on Human Behaviour in
Fire, T.J.
Shields, Editor, University of Ulster Fire SERT
Centre,
Carrickfergus, 1998, pp. 743-751.
R.F. Fahy, "High-Rise Evacuation Modeling:
Data and
Applications," Proceedings of the 13th Meeting
of the
UJNR Panel on Fire Research and Safety, March
13-20,
1996, NISTIR 6030, National Institute of Standards
and
Technology, Gaithersburg MD, June 1997, pp. 35-42.
R.F. Fahy, "EXIT89 - High-Rise Evacuation
Model -
Recent Enhancements and Example Applications,"
Conference Proceedings of the Seventh International
Interflam Conference, Interscience Communications
Ltd.,
London, 1996, pp. 1001-1005.
Availability: Planned January 2001
Price: Not set yet
Necessary Hardware: An IBM-compatible PC with
a 386 or above CPU
Computer Language: FORTRAN
Size: At least 4 megabytes of physical memory
should be able to
run the model
Contact Information: Rita F. Fahy, 617-984-7469,
rfahy@nfpa.org
Detailed Description:
EXIT89 is an evacuation model designed
to simulate the evacuation of large, high-
occupancy buildings, such as high-rises, so that
the movement of individuals can be
tracked while they travel through the building.
The model can handle some of the most
relevant components of evacuation scenarios of
interest in the evaluation of engineered
building designs from a fire safety standpoint.
These include:
• accounting for occupants
with a range of mobilities, including disabled
occupants
and young children;
• delay times, both those that can serve
as surrogates for specific pre-movement
activities that are set by the user at each location,
and random additional delays
that can account for the variability in start
times among building occupants;
• a choice of routing options -- the use
of model-calculated shortest routes that can
accommodate the simulation of an evacuation with
a well-trained and/or staff-
assisted occupant population, or the use of user-specified
directed routes that can
accommodate the simulation of an evacuation where
occupants are more likely to
follow familiar exits or ignore available emergency
exits;
• a choice of walking speeds that can reflect
the difference between normal
movement which might be appropriate in a drill
situation and emergency
movement which might be more appropriate for a
population reacting with a
sense of urgency;
• contra flows which will occur during an
evacuation when obstructions develop
along travel paths; and
• travel both up and down stairwells, which
allows the extension of this model to
buildings with occupied floors below grade level,
as well as buildings where the
path of some occupants will be up rather than
down stairs.
EXIT89 can also model the impact of smoke on an
evacuation, either through user-
defined smoke blockages or from output from a
CFAST run for the same building.
Verification examples have demonstrated
the effectiveness of EXIT89 in modeling
several evacuation exercises that were done in
a variety of occupancies. Although the
model was originally written with high-occupancy,
large-population applications in mind,
the results of these examples show that the model
can be effectively applied to smaller
buildings. While the issues of queuing and crowdedness
may not be important in smaller
buildings, the evacuation of disabled occupants,
the impact of exit choice and the
variation in pre-movement times have universal
relevance and can all be modeled by
EXIT89.
The size of the building and its
population that can be handled by EXIT89 is limited
only
by the storage capacity of the machine used. The
dimensions of the storage arrays
currently allow for up to 700 occupants in a total
of 308 nodes or building spaces over
100 time intervals. These can be changed by the
user to handle larger problems. Due to
the naming convention for nodes that the program
relies on, each floor can have up to 89
nodes and the building can have up to 10 stairways.
The program can print out the movement
of each occupant from node to node. It also
records the location of each occupant at each
time interval so that the output can be used
as input to TENAB. TENAB will calculate the hazards
to which each occupant was
exposed using CFASToutput for combustion products
and will determine when
incapacitation or death occurs. The user can suppress
this output and have the model
only print out a summary showing floor clearing
times, stairway clearing times and last
time each exit was used and how many people used
each exit.
