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Occupant evacuation model for apartment and office buildings
5ER T H 1
1
R427 ; B L D G . ; wn.2 !no. 741 ;May 1997 -Occupant Evacuation Model for
~parfnnent
and Office Buildings
(CISTI/ICIST NRC/CNRC X R C Ser
Received on: 06-03-97 I n t e r n a l r e ~ o r t .
r n a l r e p o r t ( I n s t i t u t e f
by G.V. Hadjisophocleous, G. Proulx and Q. Liu
Internal Report No. 741
OCCUPANT EVACUATION MODEL FOR APARTMENT AND OFFICE BUILDINGS
G.V. Hadjisophocleous, G. Proulx and Q. Liu
ABSTRACT
The evacuation of occupants during a fire depends on occupant behaviour, the physical environment, warnings required and the development of the fire. This
document describes the Occupant Evacuation Model for apartment and office buildings developed at the National Fire Laboratory. This model is used in the FiRECAMTM system model to compute the movement of occupants in the building and determine the number of occupants who are able to evacuate the building and those who are considered trapped in the building. The Occupant Evacuation Model is capable of handling large populations in a building up to 12,000 occupants and tracking the location of each individual during the evacuation process.
The model is validated using the results of fire evacuation studies in Canadian avartment and office buildings. This revort describes the methodologv used in the model ahd presents a comparison oflmodel resblts to data from actual drills% both office and apartment buildings.
OCCUPANT EVACUATION MODEL FOR APARTMENT AND OFFICE BUILDINGS
G.V. Hadjisophocleous, G. Proulx and Q. Liu
TABLE OF CONTENTS INTRODUCTION
...
1 MODEL ASSUMPTIONS...
2 OCCUPANT TYPE ... ... ... ... . . . . . . ... . . . ..
,. ...
2 OCCUPANT LO 3 LOCATIONS OF 0 3 DESIGN FIRES 3F m
STATE 4 TME DELAY OF OCC 4 OCCUPANT MOVING 6 BUILDING ASPECTS ... ... ... .... ... ... ... ... ... ... ... ... ... .. ... .... ... . .. ... .... ... ... ... ... ... 8 EVACUATION PATTERN 8 SMOKE BLOC 8 RESIDUAL POPULATION 9 MODELLING APPROACH...
9VALIDATION OF THE MODEL
...
13TEST FOR APARTMENT BUILDINGS . .... . .
.
. . . ...
. . . .. . . 13Resutts
...
14TEST FOR OFFICE BUILDINGS . . . .. . . 16
Results
...
... ... ... ... . .. . .. ... . . . . . . . . . ... . . . . . . . . . . . . .
17MODEL LIMITATIONS
...
18SUMMARY AND CONCLUSIONS
...
18OCCUPANT EVACUATION MODEL FOR APARTMENT AND OFFICE BUILDINGS
by
G.V. Hadjisophocleous, G. Proulx and Q. Liu
INTRODUCTION
The Occupant Evacuation Model (EVMD) is a sub-model of the Fire Risk Evaluation and Cost Assessment Model (FiRECAMTM) developed by the National Fire Laboratory of the National Research Council of Canada. The EVMD model is a time- dependent model that can be used to estimate the time needed for occupants to evacuate an apartmentfofice building in the event of a fire. The model computes the movement of occupants in the building and determines the number of occupants who are able to evacuate the building and those who are considered trapped in the building. The model is capable of tracking the location of each individual during the evacuation process.
The evacuation of occupants during a fire is a complex interaction which depends on occupant behaviour, the physical environment and the development of the fire. There are a number of different evacuation models that use either a hydraulic approach or network approach. In the hydraulic modelling approach, the movement of occupants is modelled as a stream of hydraulic flow instead of treating occupants individually [I]. In the network modelling approach, a network of nodes is used to represent the
compartments, corridors and exits that define the most realistic travel paths. The occupants can move from one node to another. But the network modelling concept, in most existing evacuation models, is only used to define the building geometry [2, 31.
The movement of occupants is still modelled as a stream of flow and the speed influenced by a crowd density relationship. Typically, the hydraulic method cannot handle mixed types of occupants in a building with individual explicit behaviour. For example, men, women, seniors, children and family groups act differently when responding to a fire. Furthermore, in most existing evacuation models, occupants are usually treated as non-thinking objects, which ignores the interaction of human behaviour and the development of the fire.
With the objective of developing a more realistic occupant evacuation model with respect to building fires, the EVMD model was developed to:
1. be able to handle large populations in a building,
2. take into account different types and abilities of building occupants with different evacuation speeds,
3. consider interactions between the occupants' behaviour and the development of the
fire, based on occupant abilities, reactions and the time delays between the moment that they discover a fire or hear a fire alarm and respond by warning others,
suppressing the fire and commencing evacuation,
4. allow occupants to select preferred evacuation paths based on their familiarity with the building instead of the shortest paths,
5 . consider queuing effects at doorways due to capabilities of those locations and
stairwells,
6. track locations of individuals as they move through the building,
7. allow occupants to evacuate to the nearest refuge floors instead of to the outside of the building.
Given these characteristics, the EVMD model was developed as a network of nodes used to represent the building geometry, including compartment doors, corridors, stairs and building exits, as well as the initial positions of occupants. The current version
of the EVMD model can be applied to both apartment and office buildings.
This report presents the fundamentals and the modelling approaches of the Occupant Evacuation Model. The model is validated using the results of fire evacuation studies in Canadian apartment and office buildings.
MODEL ASSUMPTIONS
The assumptions made for the EVMD model are based on research findings on human behaviour during evacuations and observations from fire drills, as follows:
occupants in the building may have different time delays responding to a fire, which
are obtained from the Occupant Response Model [4],
occupants may use different routes, based on their familiarity with the building, instead of merely the shortest one,
occupants may have different evacuation speeds and abilities.
Based on these assumptions, the important parameters used in this model were identified as the occupant type, occupant load, location of occupants, occupant moving speed and building and fire characteristics. Details on these parameters are given in the following sections.
Occupant Type
To model the different evacuation speeds for different types of people, six types of occupants are considered in the program. They are categorized by gender, age, grouping, and physical ability as illustrated in Figure 1.
AM Occupants
&
4
Disabled Able Bodied
FamiIy Groups Individuals
I
4
4
G
Seniors Children Adults
Men Women
Figure 1. Types of Occupants
For apartment buildings, the six types of occupants are included, as illustrated in Figure 1. For office buildings, however, the Children and Family Groups are not
considered applicable so the four types of occupants included are Disabled, Seniors, Men and Women.
The number of individuals included in the different types of occupants is based on a percentage of floor populations, which has to be input by the user. Their initial locations are assumed to be randomly distributed within the compartments.
Occupant Load
The occupant load determines the number of occupants in a compartment or an open area of the building which can be defined either by default or by the user.
Compartment is defined as an enclosure that can contain the fire during its development up to flashover. By default, there can be 1 to a maximum of 5 occupants in each
compartment for apartment buildings, and 1 to 2 occupants for each compartment for office buildings. The default number of occupants in each compartment is given by the computer based on a random calculation from the total number of occupants in the
building. The maximum number of occupants in an open floor off~ce space is
determined in accordance with Article 3.1.16 of the National Building Code of C y a d a (1995) [5], which states that the area for each person should be not less than 9.3 m
.
This value has been used as the default for the maximum number of occupants in an open area of a building. As an alternative, the user can also specify the total floor population that will be distributed uniformly in each compartment or an open area.Locations of Occupants
The locations of occupants parameter is used to categorize the behaviour of a group of occupants in their responses to a fire. Occupants in different locations of a building are subjected to different life threatening hazards and their likelihood of reacting, during the different stages of the development of a fire, is different. The
locations of occupants are determined according to their initial positions in relation to the compartment of fire origin. Three occupant groups are defined, as follows:
1) occupants in the compartment of the fire origin (OCF), 2) occupants in the level of the fire origin (OLF),
3) occupants in other levels (OOL).
The location of occupants is schematically shown in Figure 2 [4]. Occupants are assumed to be initially located in their compartment or working locations.
Design Fires
FiRECAMTM uses six design fires in the compartment of fire origin to categorize the wide spectrum of possible fire types [6], as follows:
1. flashover fire with the fire origin compartment entrance door open, 2. flashover fire with the fire origin compartment entrance door closed,
3. flaming non-flashover fire with the fire origin compartment entrance door open,
4. flaming non-flashover fire with the fire origin compartment entrance door closed,
5. smouldering fire with the fire origin compartment entrance door open,
6. smouldering fire with the fire origin compartment entrance door closed.
The occupants' evacuation of the building is performed for each of the above six design fire scenarios. For apartment buildings, cases of both occupants asleep and awake are considered, whereas in office buildings only the case of occupants awake is
OOL Floor 6 OOL Floor 5 OOL Floor 4 OLE OCF Floor3 OOL Floor 2 OOL Floor 1
Figure 2. Locations of Occupants
Fire States
Fire states are the times of occurrence of important events during the
development of the fire. These states are generated from the Fire Growth Model [ 7 ] .
There are five different fire states: (1) fire cue; (2) smoke detector activation; (3)
sprinkler activation; (4) flashover; and (5) burnout. These states are characterized by the fire characteristics and detection capacity of the building [ 6 ] , as listed in Table 1. The fire states are used to evaluate the time required for fire detection, occupant warning, response and evacuation. The EVMD model provides details of the evacuation process at each of the fire states, such as the number of occupants on every floor, stairwell and building exit.
Time Delay of Occupants
The time delay of occupants takes into account the time of occupants' perception of the fire and decision to start evacuation. The time required for the completion of perception of emergency, interpretation and decision to start evacuation, called the "time delay", is measured in timeframes and calculated according to the fire states by the Fire
Growth Model. A timeframe is an elapsed time which equals one-half the duration of a
fire growth state. In the case of very slow growth fires, such as smouldering fires, the duration of a fire growth state can be very long. Therefore, it is assumed that the
maximum duration of a timeframe would not exceed 300 s. Timeframe 0 begins with
Fire State I. The number of timeframes gives the time available for occupants to start evacuating. The relationship between timeframes and fire states is illustrated in Figure 3.
5
Table 1. Fire Characteristics
Timeframes
0 1 2 3 4 5 6 7 8 9
State V Time of fire burnout - the time that the fire is extinguished. This could be
either because all the fire load in the compartment of fire origin is consumed or because it has not spread to other combustibles.
State I State I1 State III State IV State V
I
Figure 3. The Relationship Between Timeframes and States
I ,
tResearch on human behaviour during evacuation drills has shown that the time delay for occupants to start evacuating varies according to different parameters, such as
occupant conditions, time of day of the fire and building characteristics [8]. The probabilities of occupants starting to evacuate at different timeframes according to their locations are calculated by the Occupant Response Model [4]. As illustrated in Fig. 3,
9 timeframes are considered in the Occupant Response Model. Based on the occupant
response probabilities, the EVMD model calculates the number of occupants who start to evacuate at different timeframes and locations.
Fire - F i e
-
Smoke -Heat detector-
Flashover -Bum outStarts cues detector or sprinMer
Occupant Moving Speed
The moving speed of occupants varies from person to person, and depends on their age, gender, physical ability and the density of the moving crowd. A mean value is commonly used to characterize the moving speed for a group of people. Statistical research on people movement has found that speed varies for different types of people and for different conditions [9, 101. Table 2 shows the mean stair speeds for different types of people given by Fruin [lo]. Table 3 gives the mean speeds in stairs from recent research on evacuation drills in apartment buildings by Proulx et al. [I I].
Table 2. Pedestrian Stair Speeds (mls) [lo]
Table 3. Mean Stair Speeds (mls) [ll]
Predtechenskii and Milinskii have presented the speed of movement as a function of density for horizontal paths, stairs and openings as shown in Figure 4 [9].
s < " " . ' ~ ~ ~ ~ ~ ~ : . ~ . . y ~ : . : ~ * ~ ~ ~ : ~
-
~
~ p ~ ~ ~ : * > z < * : ; $ $ j ~ * ~ g&
w$ssEs3~&
.;z;;-'r; %-:::&
<<<xe;z*:-z - . . ~ ~ ; z p * ~ ~ * 2 ~ ~+
+
\ 1
..
- - -0penlngs \ H o r i z o n t a l Paths - - Stair (descent).
. .
..Stair (ascent)--
0.2 -~ I-..\ - 2 - - - . _-
-
-
--2 . . . ...,: +...
:.*
*.i*.x. :.:<.:.:.:.:.:.:.: .=.. A>*.>:.: .:+.*:. :$&c: :*~~f;&za<>:.: :;.;*ggs3=2sSpeed (descending)
1
1.070
4
0 0.1 0.2 0.3 0.4 0.6 0.6 0.7 0.8 0.9
Occupant density, m'lm'
Figure 4. Speed of Movement as a Function of Density for Horizontal Paths, Stairs
and Openings 191
s-<.
&ss:gs;
~~3.:.~*.~~.~~.:.~:.>:.>:<.~<,:.:,:~:,:,~.:,~<,:,: 2 ";- i~<,~,..~,~~,.,.~,,<,,,.<,:.,~,.,,,.,,,,~.,.,.~.,,,.,~~~~-According to Predtechenskii and Milinskii, another influential factor on the occupant moving speed is the building's environmental condition. They identified different speeds of movement along horizontal paths for normal, emergency and comfortable conditions, as shown in Figure 5.
E m e r g e n c y - - Normal -
.
.
.
Comfortable 0 I 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Occupant density, Wn'FFigure 5. Speed of Movement along Horizontal Paths as a Function of Flow Density 191
The speeds used in the Evacuation Model are listed in Table 4. They are based on the information shown in Tables 2 and 3 as well as Figures 4 and 5.
Two evacuation conditions are used in the EVMD model by considering
emergency and normal speeds. The occupants who are closer to the compartment of fire origin normally walk faster than those further from the fire compartment. It is assumed in the EVMD model, therefore, that the occupants in the compartment of fire origin (OCF) and the level of fire origin (OLF) move at emergency condition speeds. The occupants on other levels (OOL) move at normal condition speeds.
Building Aspects
In the EVMD model, three possible floor design concepts are considered. They
are divided, open and hybrid, as demonstrated in Figure 6 . All levels are assumed to be interconnected by at least one vertical stairwell, and each stairwell is continuous from the ground level to the upper-most level. Generally, the floor design concept for apartment buildings can only be the divided type with a different design for the ground floor. By default, the number of units is the same on every floor. However, the user can specify any number of units on any floor. Office buildings can have a specific type or any combination of the three floor design concepts.
-
Blrildiig Flow Concept@ Divided
0
ElyenLiving Area Stairs
0
CorridorFigure 6. Types of Floor Design Concepts Evacuation Pattern
There are two evacuation patterns that are considered by the model, the Random and Sequential evacuation. During a Random evacuation, the occupants evacuate with little or,no direction and would likely use their familiar routes to reach a familiar place such as a lobby. During a Sequential evacuation, only occupants of certain designated floors evacuate to the ground level or to a refuge arealcompartment The evacuating floors in Sequential evacuation are the fire floor as well as one floor above and one floor below the fire floor. Sequential evacuation requires that occupants have received fire drill training, that there are floor fire wardens, that a P A system is used to send out instructions, and that there is a refuge area and compartmentation or a safe location for evacuees to seek refuge. The user can specify as many as ten evacuating floors in a
Sequential evacuation. However, only the Random evacuation is available for apartment buildings because the requirements of Seqzrential evacuation are usually not met in apartment buildings.
Smoke Block
The Evacuation Model takes into consideration the effect of smoke spread during an evacuation. The spread of smoke is calculated in the Smoke Movement Model [12]. Since it is difficult to predict which stainvell(s) could be affected by smoke, it is assumed that the stairwell nearest to the compartment of fire origin will be blocked by smoke. Smoke is assumed to spread in the stairwell two floors above and one floor below the fire floor, as shown in Figure 7. Only the occupants on the level of fire are aware that the exit is blocked by smoke, and they will go directly to the other exits to evacuate. The occupants on other levels are unaware of the smoke in the staircase. It is likely that occupants of other levels will take their normal routes to evacuate until they reach the critical boundary, then they will enter the closest floor and go to the closest alternative
exit to continue their evacuation
as
illustrated in Figure 7. This assumption is only applicable to buildings containing more than one stairwell, as in buildings with only one stairwell, occupants have no other option.Residual Population
The residual population is the number of occupants who are unable to exit the building when the stairs become untenable and remain trapped inside the building. They are subjected to the probabilities of death at their locations. The time at which stairs become untenable is called stair critical time, and it is determined from the Smoke Hazard Model [12].
Figure 7. Occupant Evacuation Flow When a Stairwell is Blocked by Smoke MODELLING APPROACH
When a fire starts on a specific floor, the Evacuation Model computes the
movement of occupants from their original locations through corridors, stairwells and out of the building. The evacuation procedure involves selecting appropriate paths and queuing due to limitations of the building, such as capabilities of doorways and
stairwells. A network modelling approach, convenient in solving complex evacuation
problems, is used.
The EVMD model uses a "smart" way to generate evacuation paths that saves computational time compared to the traditional method of searching through different
combinations of nodes [3]. The method of generating evacuation paths and queuing as
Evacuation Paths
The evacuation paths are generated on the basis of the assumption that occupants will use preferred routes to evacuate. This method relies on a network description of the building and the locations of occupants to solve the problem. A network model is a graphic representation of paths or routes by which objects, energy or generic persons can move from one point to another. Network nodes are used to represent the compartment doors, corridors, stairwells and exits, whichever will result in the most realistic travel paths. The initial positions of occupants are assumed to be uniformly distributed in compartments or in open areas, which are also represented by network nodes.
A building network is built separately for each floor plan and stairwell. The floor plan network is set according to the different floor design concepts. For the divided floor concept, the network nodes specify the compartment doors, corridors, stair exits and initial locations of occupants in each compartment as represented by the black dots in Figure 8. For the open floor concept, the network nodes are set for the exit stairs and occupants that are uniformly distributed on a grid as shown in Figure 9. For the hybrid floor concept, the network nodes are set by combining the two networks shown in Figures 8 and 9.
Figure 8. Network Nodes for Divided Floor Concept
The stairwell network is generated on the basis of the assumption that all stairwells have the same dimensions and structural layout, as show in Figure 10. The network nodes specify the turn points in a stairwell along the vertical direction.
Figure 10. Network Nodes of the Stairway
A mathematical differential equation is adopted to solve the evacuation paths problem, as given by Equation 1, which is also known as Poisson's equation.
where P represents the potential direction to a desirable exit,
S
is a source term, and x and y are the nodes' coordinates.There are two types of nodes in the network that can be weighted by a numerical value, namely the source nodes and the destination nodes. The source nodes represent nodes of danger, such as the compartment of fire origin and stair exits blocked by smoke. They are weighted by a negative value. The destination nodes represent nodes of safety, such as the exit stairs and building exits. They are weighted by a positive value. The solution of the equation gives different values of all nodes located at (x, y).
Evacuation paths will be generated for each occupant by solving Equation 1 according to the value of each node. The path follows the direction toward the node with a higher value. Based on the weights predefined for exits and the fire origin, the program calculates the appropriate path for each occupant. The preference of occupants to use different stairs and building exits to evacuate is modelled by setting different weightings at the stairs and building exits. The higher the weighting of the destination node, the higher its attraction for occupants.
Evacuation Time
The evacuation time of occupants is calculated individually, and includes the time of delay for their response, the travel time and the queuing time. The time delay of occupants starting evacuation is given by the Occupant Response Model, which gives the percentage of people who respond at a particular timeframe. The time required for an occupant travelling in the building is determined by the distance from the person's initial node to the safety node, such as a building exit or a refuge arealcompartment, divided by the moving speed. It is assumed that, at the beginning of the fire, from the time of fire detection to occupants' response, all the occupants are positioned in their units or working locations. During the evacuation, all occupants move independently with their speeds except for family groups who respond as a unit. The time required for occupants queuing is considered at doorways. The evacuation time t i for the ith individual can be ex~ressed as:
where tideb is the time delay; si is the travel speed of the occupant, d, is the distance between two nodes; Atmqueur is the queuing time at the doorway, if it is applicable.
An evacuation path may consist of n nodes, where n = I corresponds to the initial node and n = N corresponds to the end of the path or the safety node. For horizontal paths, i.e., movement on the same level, the node n can be defined by two coordinates x,,
and y,. The distance between two nodes is calculated conservatively using the orthogonal distance to account for furniture or other barrier located in the way of the evacuation paths [13], as shown in Figure 11
Figure 11. The Distance Between Two Nodes
For a vertical path, i.e., movement on the stairways, the node n can be defined by
x, y, and z, coordinates. The distance between the two nodes is then calculated by:
Also, a path may consist of I to Mdoors where queuing will be required. It has been observed that the minimum time for a person to pass through a door is about one to two seconds during fire drill studies [ I I]. The queuing time is determined by the arrival time of occupants at the door node, rn, and the maximum capacity of the stairwells. The time difference between two occupants at the doorway should be greater than one second. Occupants will queue at the doorways of stair entrances before entering if stairwells become too crowded.
The maximum capacity of stairwells is calculated based on the optimum evacuation conditions. Pauls [14] has recommended that, in the case of absence of adequate data for high-density crowd myvements down stairs in evacuations, the optimum density for best flow is 2.0 personslm .
VALIDATION O F THE MODEL
A validation of the Occupant Evacuation Model is necessary before the model can be
implemented and assumed to make reliable predictions. Data from fire drills in Canadian apartment and office buildings [15, 161 were used to compare to the results calculated from the EVMD model. First, the EVMD model is compared to a selection of fire drills in four apartment buildings by using a 7-storey building as an example. Different cases were
considered when varying the building alarm systems and the situations of occupants awake
and asleep. The model is also compared to two fire drills in off~ce buildings using a 7-storey building. Two sets of building populations with different building alarm systems were tested and compared. The influence of special conditions in office buildings, such as having fire wardens and occupants receiving regular training, are discussed.
Test for Apartment Buildings
Four fire drills were conducted in buildings selected from four different cities in Canada: Ottawa, Montreal, Toronto and Vancouver [15]. These buildings had occupants of mixed abilities, such as adults, seniors, children and people with disabilities. The information about the four buildings and occupants is summarized in Table 5.
Table 5. Summary of Data from Apartment Building Fire Drills
A 7-storey apartment building was used to run the Occupant Evacuation Model. The building dimensions were assumed to be 40 by 15 m which was designed to
reasonably represent the four apartment buildings chosen for the fire drills. The building was also assumed to have three stairwells and four exits on the ground floor. The floor population was assumed to be 20, since it is unlikely that a higher population would be
found in most apartment buildings. The number of seniors and children was assumed to be 50%. The number of disabled occupants was not counted because it was assumed that disabled occupants would remain inside their compartments and wait for rescue.
To compare the results calculated from the EVMD model with the data from fire drills, three options were considered, as shown in Table 6.
Table 6. Options Considered for Comparison with the Apartment Building Fire Drills
1 Central alarm Awake
2 Central alarm Asleep
3 Central alarm with voice Awake
The results of the Occupant Evacuation Model calculations for the three test options are compared. To be consistent with the real fire drill situations, the scenario of a
nonflashover fire with the compartment of fire origin door being closed was selected. The occupants in the building were all located on levels other than the fire floor. Figure 12 shows the percentage of occupants who reached exits plotted against time. The results show good trends for the selected test options. For the central alarm option, the cases of occupants awake and asleep are compared. As can be observed, the evacuation process for the asleep case was delayed from 2 to 5 minutes compared to that for the awake case. For the occupants awake option, the fire protection options of central alarm with voice and without voice are compared. About 50% of occupants in the building that had a central alarm system with voice are evacuated faster than in the building without a voice alarm.
The comparison of the number of occupants who did not respond and the times required for completion of the evacuation are shown in Table 7.
Table 7. Comparison of Occupants Who did not Respond and Required Evacuation Time
Figure 12. Results of Occupant Evacuation for Three Tested Options 90 m 70 60 50 40 30 -. 20 -- 10 ~- 0,
The percentage of occupants who evacuated during the fire drills is plotted against time in Figure 13, and compared to the model results. As can be observed, the evacuation curves are quite different for the four buildings tested. This can be mainly attributed to the fire protection systems in the buildings and the conditions of the alarms, including the loudness and audibility of alarm bells. The four building fire protection systems and the alarm conditions are listed in Table 8.
*
- -
-- A -- .- -. - C m h a l a l a m & ~ e --- -
CmhalalannScMep --
.
-
.Vrnalarm&A* ITable 8. Building Protection Systems of the Tested Buildings
0 200 4M) 600 800 l o w 1 2 0 0 1 ~ 1 6 0 0 1 8 0 0 m o o m Time (s)
Note: The effect of the sprinklers is not counted since the system was never activated during the fm drill
To validate the EVMD model's predictions, Options 1 and 3 were selected to
compare to the four fire drills. Since the data obtained from fire drills were only for the occupants who were present in the building and participated, the calculated results for Options 1 and 3 were scaled to the number of occupants who evacuated from the building, as shown in Figure 13. As can be observed from Figure 13, there is good
agreement between the results from Option 1 and the fire drills for Buildings 2 and 3, which had poor central alarm systems. Consequently, the calculated results are on the lower side of what was observed in the fire drills. It can thus be concluded that the Evacuation Model gives conservative results.
100 90 80 70 -Building1 60
- -
-Building2. .
-
.Building3 50- -
Building440 + Voice alarm & Awake
(option 3) 30 + C a m a l h & A u a k e (Won 1) 20 10 0 Time (sec)
Figure 13. Comparison of the EVMD Model Results to Fire Drills in Apartment Buildings
Test for Office Buildings
There were two office building fire drill results available for buildings in London and Ottawa, Ontario [16]. The information on the two buildings and their occupants is
summarized in Table 9.
A 7-storey off~ce building was used to run the Occupant Evacuation Model. The
building dimensions used were the same as those for the London building. The building
was also assumed to have three stairwells and four exits on the ground floor. Three test options were designed to compare the results to the data from the fire drills, as shown in Table 10. Option 1 was designed to have a lower building population and a central alarm
system, which was similar to the London building. Option 2 was designed with a voice
alarm added to the building's protection system. Option 3 was designed to have a higher building population and also a central alarm system.
17
Table 9. Summary of data from apartment building fire drills
Table 10. Test Options for Office Buildings
The results of the three test options are compared to the data from the two office building fire drills. To be consistent with the real situations of the fire drills, the scenario of a nonflashover fire with the compartment of fire origin door being opened was
selected. The occupants were all located on levels other than the fire floor. Figure 14
shows the percentage of occupants who evacuated, plotted against time for different cases. For the central alarm options, two different building populations were compared. As expected, the evacuation process for the case with a lower population was faster than that of the case with a higher building population. The voice alarm option presented better results than the other two options. These results are very close to what was
observed in the fire drills. It should be mentioned that occupants had been notified of the fire drills prior to the evacuation, the two buildings had fire wardens and the occupants had received regular fire drill training. These factors have not yet been considered in the current Occupant Response and Evacuation Models. It can be observed that the impact of these factors is significant by comparison to the voice alarm test option.
Consequently, the current calculated results show good trends for the selected test options. The calculated results are below what was observed in the fire drills, which is reasonable because FiRECAMTM is designed to model the real situation of a building during a fire. It can thus be concluded that the Evacuation Model gives conservative predictions on building evacuation.
London bldg. Ottawa bldg.
- - s - - C A I Low pop.
.-CAI High pop.
+ V A !Low pop.
0 200 400 600 800 1000 1200 1400
Time (sec)
Figure 14. Comparison of the EVMD Model Results to Fire Drills in Offlee Buildings
MODEL LIMITATIONS
The EVMD model is written in Visual Basic 3.0 for PC computers. The current limitations are:
maximum number of exit doors: maximum number of stairs:
maximum number of units per floor: maximum number of stories:
maximum number of occupants per floor 600
maximum number of occupants in bu~ldiny 12000
SUMMARY AND CONCLUSIONS
The EVMD model has been developed to simulate the evacuation of occupants from an apartment or office building. The model will be used in the F i R E C W model to calculate the building residual population based on the stair critical times. The
validation studies for the model were carried out based on fire drill data from Canadian apartment and off~ce buildings. The results show that the model's predictions are conservative compared to the real fire drill results. Some of the results of fire drills showed a faster evacuation than the model predicted. The primary reason is probably
that occupants were informed of the fire drills in advance. Further improvements are needed to consider some other factors which have an impact on the evacuation, such as the effect of smoke spread, fire wardens and occupants having regular fire drill training. Additional testing and verification are required whenever more data are available to develop the model further. Some of the current limitations of the model, for example, the maximum number of occupants in the building, will be changed in the future to handle much larger populations.
REFERENCES
1. Rigopoulos, G.J. and Beck, V.R., 1992, Egress Model, Centre for Environmental Safety and Risk Engineering, Victoria University of Technology, Melbourne, Australia.
2. Fahy, Rita F., 1991, EXIT89: An Evacuation Model for High-Rise Building Fire
Safety Science
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Proceedings of the Third International Symposium, pp. 815-823.3 . Watts, John M,. 1987, Computer Models for Evacuation Analysis, Fire Safety Journal, Vol. 12, pp. 237-245.
4. Proulx, G. and Hadjisophocleous, G., 1994, Occupant Response Model: A Sub-
Model for the NRCC Risk-Cost Assessment Model, Fire Safety Science -
Proceedings of the Fourth International Symposium, Ottawa, Canada, pp. 841-852. 5. National Building Code of Canada 1995, Canadian Commission on Building and
Fire Codes, Ottawa, Canada.
6. Hadjisophocleous, G. and Yung, D., 1994, Parametric Study of the NRCC Fire Risk-
Cost Assessment Model for Apartment and Office Buildings, Fire Safety Science
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Proceedings of the Fourth International Symposium, Ottawa, Canada, pp. 829-840.
7. Takeda, H., and Yung, D., 1992, Simplified Fire Growth Models for Risk-Cost
Assessment in Apartment Buildings, Journal of Fire Protection Engineering, Vol. 4, - - -
No. 2, pp. 53-66:
8. Proulx, G., 1994, The Time delay to Start Evacuating Upon Hearing A Fire Alarm, 38th Annual Meeting of Human Factors and Errronomics Societv. Nashville. TN.
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- . October 24-28, 19959. Predtechenskii, V.M. and Milinskii, A.I., 1978, Planning for Foot Traffic Flow in Building, Amerind Publishing Co. Pvt. Ltd., New Delhi, India.
10. Fruin, J., 1971, Pedestrian Planning and Design, Metropolitan Association of Urban Design and Environmental Planners, Inc., New York, NY.
11. Proulx, G., Latour, J., MacLaurin, J., Pineau, J., Hoffman, L. and Laroche, C., 1995, Housing Evacuation of Mixed Abilities Occupants, JRC Internal Report No. 661, National Research Council Canada, Ottawa, Canada.
12. Hadjisophocleous, G.V. and Yung, D., 1992, A Model for Calculating The
Probabilities Of Smoke Hazard From Fire In Multi-Storey Buildings, Journal of Fire Protection Engineering, Vol. 4. No. 2, pp. 67-80.
13. Poon, L.S. 1993, EvacSim: A Simulation Model of Occupants with Behavioural Attributes Emergency Evacuation of High-rise Building Fire, The Centre for Environmental Safety and Risk Engineering (CESARE), Victoria University of Technology, Melbourne, Australia.
14. Pauls, J.L., 1980, Building Evacuation: Research Findings and Recommendations, Fires and Human Behaviour, Edited by D. Canter, John Wiley & Sons Ltd., pp. 251- 275.
15. Proulx, G., Latour, J. and MacLaurin, J. 1994, Housing Evacuation of Mixed Abilities Occupants, IRC Internal Report No. 661, National Research Council Canada, Ottawa, Canada.
16. Proulx, G., Kaufman, A. and Pineau, J., 1996, Evacuation Time and Movement in
Off~ce Buildings, IRC Internal Report No. 71 1, National Research Council Canada,
![Table 3. Mean Stair Speeds (mls) [ll]](https://thumb-eu.123doks.com/thumbv2/123doknet/14218418.483196/10.933.219.666.702.983/table-mean-stair-speeds-mls-ll.webp)
