Refuge Floor, Firefighters, and Elevators

In this example, we show some advanced evacuation features of Pathfinder: a refuge floor, evacuation using banks of elevators, and firefighters in stairs moving against the flow. Each of these scenarios could arise in the evacuation of a high-rise building.

Our simplified model has seven floors, with a refuge on the central floor, the red and green floor in Figure 1. All the floors are connected by stairs. Evacuation occurs from the refuge floor using elevators. During the evacuation, firefighters arrive on the refuge floor and proceed to prescribed locations using stairs.

Figure 1: Pathfinder model with refuge floor evacuated by elevators.
Figure 1: Pathfinder model with refuge floor evacuated by elevators.

Profiles

Our model uses three profiles. 90% of the occupants are assigned a profile with a normal speed (0.8 to 1.6 m/s) and 10% of the occupants have a profile with a slow speed (0.2 to 1.0 m/s). Both profiles have a zero Priority Level.

The firefighter profile has a constant speed of 1.19 m/s, but with a Priority Level of 1. This means that when conflicts occur during movement, the firefighters will have priority.

Behaviors

All 700 occupants are assigned a behavior that instructs them to: (1) proceed to the refuge, and then (2) go to elevators. This means they will use stairs to walk to the refuge, then wait to be evacuated by elevators.

The 28 firefighters are assigned behaviors to: (1) use the Fire Fighter elevator to move to the refuge floor, then (2) in groups of four proceed to locations on a specific floor, (3) wait 600 seconds at their specified location, and then (4) use elevators to exit.

Elevators

The model has 12 elevators arranged in two banks. All elevators in a bank respond to a call to any of the elevators in the bank. These elevators discharge at the ground floor and pick up occupants only on the refuge floor.

One elevator is assigned to the firefighters. This elevator discharges on the refuge floor and picks up on the ground floor.

Refuge Floor

The refuge floor is shown in Figure 2. The green area indicates the refuge room to which all occupants proceed. The red circle is the location on that floor where the firefighters will wait. The gray rectangles are the elevator locations. The blue occupants have normal speeds and the purple occupants have slow speeds.

Figure 2: The refuge floor showing the refuge room to which all occupants proceed.
Figure 2: The refuge floor showing the refuge room to which all occupants proceed.

Evacuation Results

The sequence of evacuation is shown in Figures 3 through 5. Figure 3 shows the early movement of the occupants to the refuge floor. The occupants use stairs to move to the floor and then form queues waiting for the elevators to arrive. The contours  show the density of the occupants.

refuge_density
Figure 3: Occupants are moving toward the refuge floor and forming queues to wait for the elevators.

Figure 4 shows the priority movement of the firefighters on the stairs. You can see four firefighters moving up the stairs. The occupants evacuating down the stairs defer to the higher priority of the firefighters.

Figure 4: Priority movement of the firefighters against the occupants on the stairs.
Figure 4: Priority movement of the firefighters against the occupants on the stairs.

Figure 5 shows the firefighters waiting at their assigned locations. Most of the occupants have now evacuated. Their paths are shown as lines on the floors.

Figure 5: Most occupants have now evacuated. The firefighters are waiting at their assigned locations.
Figure 5: Most occupants have now evacuated. The firefighters are waiting at their assigned locations.

Download Pathfinder Model

elevator-refuge-floor-with-fire-fighters.pth

Comments or Questions

This post was written by Daniel Swenson. For comments or questions, send email to support@thunderheadeng.com.


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