A Review of Building Evacuation Models - NIST Virtual Library

number of people in the stream, f is the area of horizontal projection of a person, w is the width
of the stream, and L is the length of the stream of people. The maximum density of their results
is 0.92 m 2 /m 2 , and WAYOUT uses the adult in mid-season dress (0.113 m 2 ) to calculate f.
Density is monitored on each building section (Predtechenskii and Milinskii data distinguishes
between travel on horizontal components, through doorways, down stairs and up stairs).
WAYOUT considers flows throughout the route from door to door of each compartment.
Output: The output from this model is the complete movement time and individual times when
each twig is evacuated.
Use of fire data: None.
Import CAD drawings: No. The user inputs geometrical configuration, including the length
and width of twigs, width of doors, and the population numbers in each twig.
Visualization capabilities: 2-D visualization of the evacuation tree is provided.
Validation studies: An evacuation study was performed on the Milburn House in Newcastle,
UK as a fire drill. The results are provided in Table A.3. The number of evacuees was
monitored at each exit. The fire drill and simulation results are provided below for this 7-story
building:
Table A.3: Milburn House validation results for WAYOUT
# of Evacuees Time of the gap in flow (s) Time of evacuation (s)
Tested Computed Tested Computed
Exit 4 40 - - 60 40 – 99
Exit 8 48 - - 156 164
Exit 10 248 220 168 266 243
The calculations shown in the table were made for those exits which a large number of occupants
used. The developers note that the occupants may not be moving as fast as they may in an actual
evacuation because of the fact that their movement was a drill. This may be an explanation for
the computed values providing a shorter evacuation time in most cases. Some difficulties in this
validation work were the incomplete response of all occupants involved, and minor
discrepancies in the records of occupants passing through certain stairs and exit doors. The
developers note, though, that this comparison “seems to be satisfactory.”
Special features:
Delays/pre-movement time – Yes, user enters start time for evacuation if the twig is a blind end.
This is so the user can incorporate time delays in receiving the alarm cue.
Route choice of the occupants/occupant distribution – Only 1-route
Limitations: Only merging flows are considered. The model allows for up to 400 “twigs.”
A-11