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A Review of Building Evacuation Models - NIST Virtual Library

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are applied to the entire population. The assignment <strong>of</strong> equations to the entire population <strong>of</strong> a<br />

model from another field <strong>of</strong> study that can be related to human behavior in a fire, in this case<br />

fluid flow, has been referred to as a functional analogy 108 . The movement method <strong>of</strong> this model<br />

will be referred to as the functional analogy <strong>of</strong> fluid flow, with the underlying method <strong>of</strong><br />

assessing the density <strong>of</strong> the space elements.<br />

When moving from one space to another in the building (through a link), the movement is<br />

dependent upon the number <strong>of</strong> evacuees ready to move, the availability capacity <strong>of</strong> the space<br />

they would like to move into, the width <strong>of</strong> the opening, and the number <strong>of</strong> space elements<br />

combining in that link. The model incorporates all <strong>of</strong> this into overriding equations for the entire<br />

population to follow. When the evacuees reach the hall, they use the exits that would minimize<br />

egress time, taking into account crowding <strong>of</strong> the exits, the number <strong>of</strong> evacuees reaching the exits,<br />

the distance to the exits, and the rate <strong>of</strong> egress (persons/second) at each exit.<br />

Output: The output from the model is the total evacuation time and a visualization presentation.<br />

The visualization shows the number <strong>of</strong> evacuees in each space element with five levels <strong>of</strong><br />

density. When crowding forms at the doors <strong>of</strong> each space element, for example, blackened arcs<br />

can be seen surrounding the doorway to signify higher density.<br />

Use <strong>of</strong> fire data: None.<br />

Import CAD drawings: No. The user inputs the length and width <strong>of</strong> space elements. Not<br />

much more information is provided.<br />

Visualization capabilities: 2-D visualization <strong>of</strong> the levels <strong>of</strong> density on the floor plan, as<br />

explained in the output section.<br />

Validation studies: Validation studies <strong>of</strong> the fluid model were performed using measured<br />

evacuation times from the seven pavilions <strong>of</strong> the Tukuba International Expo in 1985. The egress<br />

times <strong>of</strong> the occupants in each pavilion were calculated using two different cases, 1) the L-shape<br />

approach is considered in the theater area, and 2) the theater spaces consists <strong>of</strong> space units<br />

connected by paths (rooms and paths). The results are shown below in Table A.16:<br />

Table A.16: Validation results from the Tukuba International Expo<br />

Pavilion # Egress Times (s) Average (s) Calculation 1) Calculation 2)<br />

1 61, 71, 75, 60, 64 66.2 52 62<br />

2 174, 154 164 137 275<br />

3 71, 80, 77, 78, 79 77 50 76<br />

4 94, 111, 102 102.3 72 89<br />

5 70, 123, 84, 77 88.5 34 59<br />

6 160, 152, 166, 157 158.8 100 107<br />

7 148, 118, 130, 121, 131 129.6 70 88<br />

A-92

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