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