Fire Sub-Group

www.NEWBuildSCanada.ca

Fire Sub-Group

Xiao LiWith,Alejandro MedinaProf. George Hadjisophocleous Andrew HarmsworthChristian Dagenais

1

Tall Wood Building Project

http://www.newbuildscanada.ca/


Fire Risk Modeling using CUrisk The objective is using CUrisk to

compare the fire risk of the proposed combustible building with the fire risk of a non-combustible building.

Buildings for comparison:• The proposed combustible construction

• 15% of total room surface area non-protected (1 wall exposed)

• A comparable non-combustible construction



Fire Risk Modelling

In the 2nd meeting:• Results of fire risk analysis based on fires

on the 2nd floor.• Fire growth in the fire room• Effects of sprinklers and fire department on

fire development• Effects of CLT wall exposure areas on fire

development• Effect of reliability of fire sprinklers on the

fire risk of the building



Outline

CUrisk modeling results today• Fire Scenarios covering all the floors

• Normal scenarios in the residential floors• Extreme fire scenarios (lobby fire and night

fires)• Response and Evacuation process

• Probability of evacuation following response • Remaining percentage of building occupants• Occupants Evacuation times

4



Floor Plan

Ground floor planResidential floor plan 2nd to 20th storey

2-BedRmApt.

2-BedRmApt.

1-BedRmApt.

2-bedroomApt. 2-BedRm

Apt.

1-BedRmApt.

Corridor

Commercial Rooms

Lobby Lobby

Commercial Rooms

Commercial Rooms

Commercial Rooms



Occupant loads According to building code

Dwellings: 2 person per sleeping roomMercantile uses: 3.7 m2 /person

Occupant loadsFirst storey: 124 personsResidential storey: 20 persons

Totally in the building: 504 occupants

6

4 p

4 p

4 p

4 p

2 p

2 p

31 p 31 p

31 p 31 p

First storey

other storey



Fire Scenarios Residential Fires in

all the residential storeys• Apt 11 on 2nd floor• Apt 18 on 3rd floor• Apt 25 on 4th floor• …• Apt 137 on 20th

floor Extreme scenarios

• Fire In the lobby on the first floor

• Night fires without fire suppression

fire

Scissor stairs

Apt.11



Occupant response to fire

8

Probability of evacuation following occupant response timewhen fire occurs in room 11 on the 2nd floorNo fire suppression and detection and alarms (solid and dash lines)

0 2 4 6 8 10 12 14

0.0

0.2

0.4

0.6

0.8

1.0

Proposed combustibleconstruction Non-combustible

construction

Ave

rage

Pro

babi

lity

of E

vacu

atio

n

Time (minutes)

Proposed combustible constructionWhen detectors/alarmsare available


GEORGE

Typo Construction


Evacuation Remaining percentage

9

Occupant remaining percentage in the building versus timewhen fire occurs in room 11 on the 2nd floorNo fire suppression and no detectors and alarms (red and black)

0 5 10 15 200

20

40

60

80

100

Occ

upan

t Rem

aini

ng P

erce

ntag

e in

the

Bui

ldin

g

Time (minutes)

Proposed building, when Detectors /Alarmsare available

Non-combustible building

Proposed building


GEORGE

Why is the proposed building faster to evacuate than the non-combustible building?


Occupant evacuation times

10

Average evacuation time for each occupant (among 504)when fire occur on 2nd storey room 11A comparison of the proposed combustible building and a non-combustible building

1 101 201 301 401 5040

2

4

6

8

10

12

14

16

Ave

rage

Eva

cuat

ion

Tim

e (m

inut

es)

Occupant Number

Storey number

124 pon 1st floor

Non-Combustible building

2nd floor

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

20 p on each residential floor

Proposed buildingwhen detectors and alarms are available

Proposed building



Fire risk comparison

Considering possible fire senarios on each residential floor

• Same probability occurring on each floor

Considering reliability of • sprinklers, • detector/alarms and,• Fire Department actions

Totally 152 fire scenarios for each type of building

• The proposed building • Comparable non-

combustible building

11

Scenario Probability

Fire Depart.

0.7

Detector and Alarm

0.8

Sprinkler

0.95

Room fire1/19

A Fire on each

residential floor

19 storeys

Yes

Y Y 0.024

N 0.016

N Y 0.006

N 0.004

No

Y Y 0.0013

N 8.4e-4

N Y 3.16e-4

N 2.1e-4



Expected fire risk comparison

12

Expected Casualties (person)

0

0.1

0.2

0.3

0.4

Non-CombProposed building

Expected Fire Loss (k$)

0

2

4

6

8

10

Expected Casualties when a fire occur on any residential storeys among all the occupants (504)

Expected Fire Loss when a fire occur on any residential storeys in the whole building



Extreme fire scenarios

Low probability of occurrence Fires in the lobby Night fires where fire suppressions systems

are not available Earthquake induced fires are not considered

due to its complexity, but comments may be provided.

13



Fire in the lobby CUrisk results showed that: Fire in the lobby can cause

hundreds of casualties and a lot more damages due to fire spread to adjacent heavy-loaded shops

Smoke and heat block all the exits

However, fire spread to upper storeys may be limited in the podium because of its non-combustible construction and remote window openings from upper storeys (vertical external fire spread)

14

LobbyLobby



Fires at night without fire prevention

Worst scenarios when no fire suppression and detection system

Compared with daytime fires without fire prevention

Expected overall risk by considering possible scenarios on every residential floors (19 fire scenarios)

Results show fire losses are same but night fires may cause lots more casualties than daytime fires.

15

Casualties (person)02468

10

Fire Losses (K$)0

50100150200250

Daytime Night Fires

Comparison of Expected risk between daytime fire and night fires in the proposed building.



Reliability of Sprinklers

Last meeting showed that reliability of sprinklers is the most important factor in reducing the fire risks.

When sprinklers are installed and work reliably (P_Sprinkler = 1) :

Risk (proposed building) ≈ Risk (Non-combustible building)

Possible solutions: • Fast response sprinklers with high reliability and

suppression efficiency• Reliable fire detectors and alarms that can

provide quick fire cues to occupants.

16



Summary Possible fire scenarios are simulated on all the residential

storeys, and results showed that fire risk of the proposed building is close to (or slightly higher) than the non-combustible building.

Evacuation simulation results showed that occupants can evacuate out of the building with a reasonable time frame; and occupant evacuation times in the proposed combustible building are slightly shorter than a comparable non-comb. building.

Again, high reliability sprinklers (good efficiency) can prevent the fire in its infancy, thus can avoid faster fire growth in the combustible compartment (especially in the case of wood panel exposure).

Fire in extreme scenarios may cause significant life risks and fire losses, though occurrence probabilities are low.

17


Documents

Fire Sub-Group