A Review of Building Evacuation Models - NIST Virtual Library

Table A.6: Validation study results for the Simulex model
Building
Observed Total
Evacuation Time (s)
Predicted Travel Time
(s)
Predicted Total
Evacuation Time (s)
Lecture Theater 90 93 131
Law 170 161 188
Commerce 220 178 202
The predicted total evacuation times were obtained by adding the predicted travel times (since
Simulex did not model pre-movement delays) to the observed pre-movement delays. Simulex
used the following assumptions to model the three buildings:
• The occupant type used for the simulations were “office type” which specifies the walking
speed and body size to be 40 % male, 30 % female, and 30 % average (this distribution was
used by Simulex at the time of the validation study)
• The default distance map was used, which assumes the shortest path chosen by occupants
• Pre-movement times were not simulated by Simulex and were dealt with separately to the
computer modeling.
Simulations run by Simulex 43 using an estimated (instead of observed) occupant load derived
from the Life Safety Code Handbook 44 for assembly space as well as pre-movement delays as
suggested by the Fire Safety Engineering in Buildings 45 have also been compared with observed
results. The validation paper also goes on to comment on the conservative values presented in
the literature, however that discussion goes beyond the scope of this review 43 .
The results of the study show that the simulated evacuation times were similar to the observed
results (as shown in Table A.6) when Simulex used the observed pre-movement times and
occupant loads. Even though it seemed that Simulex provided a conservative time for the lecture
theater, it underestimated the evacuation time for the law and commerce buildings. Olssen and
Regan stated that Simulex can be used “with confidence to simulate travel times for buildings”
discussed previously 43 .
Special features:
Manual exit block/obstacles – Yes, the user can create an alternate distance map for an
individual, group, or several groups in which certain exits are blocked from the population using
the distance map.
Fire conditions affect behavior No, the developers are currently working on importing CFAST
data into their evacuation model.
Defining groups – Yes, groups can be defined and assigned to have a certain occupant
characteristic, distance map, and distribution of pre-movement times.
Disabilities/slow occupant groups – Yes, the user can assign lower velocities to individuals or
groups in a simulation.
Delays/pre-movement time – Yes, the user can choose either a triangular, random, or normal
distribution for each group of occupants.
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