Instructions for Authors

12th conference on performance-based codes and fire safety design methods, 25-27 April 2018, Hawaii, USA

12th Conference on Performance Based Codes and Fire Safety Design Methods

High-Rise Residential Building using Cross-Laminated Timber (CLT)

Mitsuho Enomoto, Akeno Facility Resilience Inc. Kiyoshi Fukui, Vice president of SFPE Japan Chapter Akihide Jo, Takenaka Corp. Masahito Kikuchi, Akeno Facility Resilience Inc. Jun Kitahori, Akeno Facility Resilience Inc. Tomoko Kouta, Nikken Sekkei Corp. Tomoyuki Someya, Nikken Sekkei Corp. Shinichi tsuchiya, Akeno Facility Resilience Inc. Yoshikazu Minegishi, Takenaka Corp. Ai sekizawa , Tokyo University of Science



Fire Engineering Solutions for the Built Environment: The 12th International Conference on Performance Based Codes and Fire Safety Design Methods October 25-27, Honolulu, Hawaii, USA

Case Study Building Specifications – High-Rise Residential Building using Cross-Laminated Timber (CLT) I. Objective: The objective of this case study is to prepare a performance-based fire safety strategy report for a Residential building using Cross-Laminated Timber (CLT). The building will be residential with retail incorporated on the ground floor and carparks below ground. The performance-based fire safety analysis and design should meet the following fire and life safety goals: 1) Safeguard occupants from injury due to fire until they reach a safe place. 2) Safeguard fire fighters while performing rescue operations or attacking the fire. 3) Design to avoid structural failure in the event of fire. 4) Design to avoid building-to-building fire spread. II. Building Description: General descriptions: - The building is a residential building located in the financial district of a large city - Its target market is members of the ‘gig’ economy (flexible and transient) - It contains a total of 32 floor levels (B2, B1, L1 to L30) - B1 to B2 are carparks. L2 to L30 are residential - Some retails areas are located on the perimeter of the building on L1 - The building foot print is 40 m x 40 m - The floor-to-floor height is 3 m per carpark level and 3 m per residential level - Carpark levels B2 and B1 are below ground - All facades of the building are located within 2 m of the site boundary - Each apartment will be a separate unit title, with carparks designated as auxiliary titles to the primary. The Retail stores will be leased and L1 will form a single title. Stairs, corridors and common areas such as foyers will be common property. Access and egress: - Main entry to the building is located on L1 on the west side, facing the main street. - Vehicle entry to the carpark via a lane way located on the north side - All levels (B2-L30) are connected by elevators (central core) - Retail areas on ground level have direct access/egress to the outside. Specific client/architectural requirements: - Due to current and future market projections the building will maximize transient use, using platforms like AirBNB. - Flexibility must also be provided to facilitate permanent (long stay) occupant. - The highest possible environmental standard should be delivered (LEED Gold or equivalent). - There is an architectural desire to expose parts of the CLT as a design feature. - There is a desire to use elevators for occupant self-evacuation.

1


III. Project Report: It shall be demonstrated that the above fire and life safety goals have been addressed by providing a detailed project report. There is no page limit to the project report. In particular, the report should pay particular attention to the behavior of the transient users of the building is considered. Additionally, the structural behavior of the CLT on the project goals should be addressed as well. This report should address at least the following items: a. b. c. d. e. f. g. h. i. j. k.

l. m. n. o. p.

The performance criteria selected to assess the fire safety goals and objectives. A fire risk assessment (unless the design approach (c) is risk-informed or risk-based) A description of the fire safety design approach used. Fire safety measures selected. How safe egress will be provided for building occupants under a variety of reasonably foreseeable fire scenarios. How human behavior and the transient use was considered. The fire scenarios evaluated, and how they were selected. A discussion of how the proposed fire safety measures address the performance criteria. How safety for fire fighters will be provided, in particular given the use of CLT. How safety for persons with disabilities will be provided. Fire safety tools and design methods used in the analysis and designs (i.e., fire models, calculation methods, statistics, fire test data, etc.), including why the tools were selected. Which aspects of the analysis were modeled, and which were based on engineering judgment. Fire safety management requirements, including material control, change of occupancy requirements, education and training, etc. Discussion of how uncertainties were addressed. References for all engineering tools and methods, input data, fire tests, occupant characteristics, statistics, etc. Drawings and specifications as necessary.

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Contents Executive Summary

1

Chapter 1 Strategy for Fire Safety 1.1 Japanese code for wooden buildings 1.2 Architectural design 1.3 Strategy for fire safety

2 3 13

Chapter 2 Design Fire 2.1 Design fire when the sprinkler system is not activated 2.2 Design fire when the sprinkler system is activated

17 19

Chapter 3 Smoke Analysis 3.1 Smoke control strategy 3.2 Smoke Control Design on Lower Floors to Safeguard Occupants 3.3 Fire safety design on upper floors

22 24 32

Chapter 4 Evacuation Planning 4.1 Objective 4.2 Strategy 4.3 Assumed Evacuation Scenario 4.4 Setting of elevator evacuation 4.5 Design Calculation 4.6 Conclusion

41 41 41 42 46 59

Chapter 5 Fire Spread and Fire resistance design 5.1 Horizontal fire compartmentation 5.2 Compartment fire temperature 5.3 Control of Vertical Fire Spread 5.4 Modeling of heat release rate from openings when multi-floors burning 5.5 Validation cases 5.6 Result of fire spreading time

60 60 62 65 66 67

Chapter 6 Effective Firefighting Plan 6.1 Objective 6.2 Building Performance requirements 6.3 General Planning and Firefighting Scenarios 6.4 Conclusion

75 75 75 82

Chapter7 Fire safety management for the transient users 7.1 Characteristics of the transient users 7.2 Fire safety management for the transient users

83 83

Chapter 8 Conclusion and future discussion 8.1 Conclusion and future discussion

84


Appendix

Appendix1; Smoke Insulation Condition and Setup of Air Supply Flow Condition

Appendix 2; Calculation of activation time of heat detector in a residential unit


EXECUTIVE SUMMARY In Japan high rise residential building using wooden materials is also required no structural failure even though after fire. To accomplish this goal we should cover all the wooden members by inflammable materials. With such design, the building can’t be identified as wooden building and not satisfies the specifications of this case study. Consequently our design proposal is designed totally as 45 minutes fire resistance. 45 minutes is decided in consideration of evacuation and firefighting time. We designed this building with two different type of floor plans, one for upper floors and the other for lower floors. Upper floors have an open aired void in center surrounded by open corridors. We verified smoke behavior in this open void and secure the safety of the occupants. Lower floors do not have an open void and corridor to each residential unit is an inner space. So we install pressurizing smoke control system to staircases and elevator shafts to suppress the smoke invasion from unit of fire origin to the corridor. Evacuation time is an important factor of this building because this building is designed as 45 minutes fire resistance and structural robustness is not secured 45 minutes after the fire break. We evaluated the evacuation time with the evacuation strategy using both stairs and elevators. We expect firefighting activity to secure the structural safety of this building in case of fire. We make sure that fire fighters can start within 45 minutes at latest. Horizontal fire spread is controlled not to occur even to the neighboring residential unit. Vertically fire spread is suppressed within three unit to secure the firefighting activity. For transient users, we make sure the evacuation safety with simple layout plan, corridor not to be contaminated by smoke, easy evacuation with elevators.

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CHAPTER 1

STRATEGY FOR FIRE SAFETY

1.1 Japanese Code for wooden buildings In japan most of the building was made by wood in Edo era and big fires as whole the city was burnt out were frequently happened. By this reason from the beginning of the Meiji era (150 years ago) the government tries to build a city with inflammable materials such as steel concrete or bricks, and restricted the wooden buildings especially in the city center with high density of buildings. Even current building codes restrict the wooden buildings in huge area or more than 3 stories.  Building Standards Law of Japan ・Restriction of wooden building Maximum area of wooden building should be less than 3,000 ㎡ Buildings over 3,000 ㎡ should be constructed as fire resistant building . Maximum height of wooden building should be less than 13m Wooden buildings with more than 3stories or over 3,000 ㎡ should be constructed as fire resistant building. ・Fire compartment Maximum area should be less than 3,000 ㎡(with automatic fire distinguishing system) 1,500 ㎡(without automatic fire distinguishing system) ・Smoke exhaust system for evacuation Smoke exhaust system more than 1 [m3／m2・min ] should be installed . ・Evacuation stairs Two evacuation stairs with smoke controlled vestibule should be installed for 40m× 40m floor plan. ・Emergency Lighting Emergency Lighting should be installed. The illumination should be more than 1 [Lux ]. ・Fire resistance We should design high-rise residential buildings as “fire resistance building” that means the building is required no structural failure even though after fire. All the structural members should be 1-3hours fire rated.  Fire Service Act Following extinguishing system should be installed ・Sprinkler systems ・Fire department standpipe ・Sprinkler system with hose connection ・Standpipe wit hose connection ・Fire extinguisher ・Automatic fire alarm system ・Luminaire for emergency exit system ・Smoke exhaust system for fire fighting

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1.2 Architectural design We designed this building with following ideas. ・Floor plan We designed two different plans upper floors and lower plans. Upper floors have an open aired void in center surrounded by open corridors. At the center of the open void, there are one staircase and two elevators for usual use and one fire lift. Balcony is surrounding the building, and the façade of the building is set backed every other span. The position of the set-back is different every other floors to avoid the fire spread to upper floors. Lower floors do not have an open void and corridor to each residential unit is an inner space. At the center two staircases, two elevators for usual use and one fire lift. Staircases and elevator shafts are pressurized to suppress the smoke invasion from unit of fire origin to the corridor. Balcony is surrounding the building, and the façade of the building is set backed every three floors. Level9 is just between the upper floors and lower floors. This is the intermediate refuge floor and has a wide open air balcony. At this floor both elevators for upper floors and lower floors stop. This is the top floor of the one stairs and the other stair does not go through this floor and evacuees from upper floors go out of the stirs and return to the stairs through corridor and vestibule. The core of this building at the center consist of stairs with vestibule, elevator for usual use and fire lift is made of reinforced concrete to protect such important facilities for evacuation and firefighting as stairs and elevators. ・Section Section is divided to upper floors and lower floors. Upper floors are set –backed every other floor, and lower floors are set –backed every three floor to suppress the fire spread. Level9 is the floor between upper floors and lower floors, and intermediate refuge floor. ・Stairs and elevators This building has two stairs and one is from the ground floor to the top and the other is from the ground floor to the intermediate refuge floor. So lower floor has two stairs but upper floors has just one stair. Elevators are two banks, one serves lower floors and the other serves upper floors. Each bank consists of two elevators. One fire lift serves all the floor of this building. Stairs Elevator for usual use Fire lift

Figure1.0. Stairs and elevators

3


Figure1.1. Floor plan of Level 1 (Ground floor) 4


Figure1.2. Floor plan of Level 2-3,5-6,8-9,11-12,14-15,17-18

5


Figure1.3. Floor plan of Level 4, 7,10,13,16

6


Figure1.4. Floor plan of Leve19

7

Intermediate refuge floor


Figure1.5. Floor plan of Leve20, 22, 24,26,28,30

8


Figure16. Floor plan of Leve21.23.25.27.29

9


Figure1.7. Section 10


Slab CLT covered by concrete

Hand rail Fire resistant glass (Resistant to radiation with sandwiched forming material)

Figure1.8. Section Detail

11


・Structural Design We choose the center core type plan. The Center core is designed by RC flame for resistant about horizontal (earthquake and wind) force. RC center core is very efficient for evacuation at fire. The area surrounding the core is a residence area. We think this area is required a comfort to work or habitat, column and ceiling is designed by wood.

All structural members

Partially cut out

Figure1.9. Image of Structural Design

Wooden members Figure1.10. Structural

Floor Plan

12


・Structural members Upper part of the floor is made of reinforced concrete having thickness of 80mm, and lower part is made of CLT having thickness of 255mm RC is used to avoid the structural failure. 255mm thickness of CLT is assumed 210mm for structure and 45mm for fire stoppage layer. Columns are made of laminated wood, and those of set –back floors and intermediate refuge floor are covered by gypsum board to stop fire spread to upper floor. Size is 1300mm square. Beams are made of steel covered by fire resistant material. Size is 250H×100W Walls are sandwich board made of gypsum board as a non-flammable material covered by CLT on both side. 250H×100W 80 210 40

255

Reinforced concrete CLT

Laminated wood

1300

CLT

Non-flammable material Section of Wall

Figure1.11. Structural

13

Members


Open Void Upper Floors

Intermediate Refuge Floor

Laminated Wooden Column

Slab CLT +Concrete

Core Concrete

Lowere Floors

Figure1.12. Composition of structural members

14


1.3 Strategy for fire safety In our case study, we set up the strategy for fire safety considering following issues. 1.3.1 Goal of fire resistance Such high-rise residential building as this case study is usually required any structural failure even though after fire. However in this case study to expose parts of the CLT as a design feature is required by an architect. In this condition exposed wooden parts keeps on burning till it would be burnt away. So structural failure of this building can’t be avoided. Covering all the wooden pars by inflammable material secure the structural safety but it is out of our scope. Consequently we set up the goal of fire resistance about this building 45minutes. However to avoid collapse of this building the core of this building at the center and upper part of the floor slab are made of reinforced concrete. ・The goal of fire resistance of this building is 45 minutes fire resistance. ・This building doesn’t have any structural failure within 45 minutes after fire break. ・Evacuation of the occupants should be finished within 45 minutes after fire break. ・Water-discharge by firefighters should be start within 45 minutes after fire break. 1.3.2 Evacuation strategy Fire break of this type of residential unit could be easily recognized by the residents because the area of residential unit is not so large and sprinklers are installed to each residential unit. Therefore we mainly focused to secure the evacuation safety within the fire floor and total building evacuation considering the vulnerable people and gig people (We omitted the evaluation of evacuation from fire-occurred residential unit). However this building could have any structural failure 45 minutes after fire, therefore we evaluate whether evacuation of all the residents of this building can be finished within 45 minutes or not. 1.3.3 Smoke control strategy To secure the safety of evacuation from each residential unit to the stirs and elevators, the corridor should be clear from the smoke coming from the unit of fire origin. For this goal the corridor of upper floor is open to the open-air void space, and the stairs and elevators of the lower floors is pressurized to avoid the invasion of smoke to the corridor. 1.3.4 Control of fire spread If fire spread to large area of this building, it became difficult to extinguish the fire. So we suppress the fire spread within three residential units in any cases. Each residential unit is fire is surrounded by 45 minutes fire rated CLT sandwich board. Upper floors are set –backed every other floor, and lower floors are set –backed every three floor to suppress the fire spread. Consequently, fire can spread within three units at the same position of floor layout. 1.3.5 Firefighting strategy To avoid the collapse of this building, discharge of water by firefighter should be started before 45 minutes from fire break. We evaluate the time line of the firefighting and make sure about it.

15


1.3.6 Fire safety of the transient users It is required that fire safety of the transient users of this building should be secured. For this goal following points are taken into consideration in our proposal. ・Evacuation safety with simple layout plan ・Corridor not to be contaminated by smoke ・Easy evacuation with elevators.

16


CHAPTER 2 DESIGN FIRE There are many combustibles in a residential unit, and quantity and placement of them are greatly vary by every residential unit. We designed the fire using some numerical value determined in Building Code of Japan. And we assumed two scenarios when the sprinkler system is activated or not. 2.1 Design Fire When the Sprinkler System is not Activated ・Fire growth rate We calculated the fire growth rate using the following equations determined in Building Code of Japan. α = 𝛼𝛼𝑓𝑓 + 𝛼𝛼𝑚𝑚 0.0125(𝑞𝑞𝑙𝑙 ≤ 170) 𝛼𝛼𝑓𝑓 = � 5/3 2.6 × 10−6 𝑞𝑞𝑙𝑙 (𝑞𝑞𝑙𝑙 > 170)

(2-1) (2-2)

where α is fire growth rate [kW/s2] αf is fire growth rate by the fire load [kW/s2] αm is fire growth rate by the interior finish material [kW/s2] (=0.35: wood) ql is the fire load [MJ/m2](=720) The fire growth rate is shown below. α = 0.1504 + 0.35 = 0.5004[kW/𝑠𝑠 2 ]

・Heat release rate In the phase of fire development, the heat release rate Q is defined as Q=αt2. In the phase of fully developed fire, the heat release rate depends on the ventilation factor, and is defined as 𝑄𝑄𝑚𝑚𝑚𝑚𝑚𝑚 = 1500𝐴𝐴√𝐻𝐻. Every residential unit has two windows. The ventilation factor of these windows are shown in Figure.2.1. Window 2

Window 1 Window 1 Window 2

Width [m] 2.5 4.0

Height [m] 2.0 1.0

Figure2.1.The ventilation factor of windows

17

Ventilation factor [m5/2] 7.07 4.00


The heat release rate of design fire is shown in Fig.2-2,.

Heat Release Rate ［ｋW］

30000

Heat release rate[kW] 発熱速度

25000 20000

Qmax=16605[kW]

15000 10000 5000 0

0

100

200

300

400

500

600 Time［sec］

Figure2.2.The heat release rate of design fire

18


2.2 Design Fire When the Sprinkler System is Activated ・Fire scenarios In a building where the sprinkler system is installed, we assume the 4 fire scenarios as shown in Figure2.3.

Fire

Sprinkler works

S1

S2

Succeed to extinguish

Succeed to control Design fire, when the sprinkler is activated.

Sprinkler doesn’t work

S3

Failure to control

S4 Fire spread Qf : Heat release rate [kW] Qsp : Heat release rate on a sprinkler’s activation time [kW]

Figure2.3. Fire scenarios when the sprinkler systems is installed in a building [1]

When the sprinkler system is activated and a fire is extinguished (S1), the occupants and the fire fighters in the building are safe. If the sprinkler system is activated but a fire could not be suppressed (S3), the fire may spread. In this case, we assume the same with S4, when the sprinkler system is not activated. Therefore, we verify S2 case as the design fire when the sprinkler system is activated and a fire is controlled.

19


・Calculation of activation time of sprinklers We calculated the activation time of sprinklers when the temperature of the thermal part of sprinkler head becomes the detecting temperature. The temperature of the thermal parts of the sprinkler heat was calculated using the following equations by Heskestad, et al. [2] and Bill [3].

dTe u1 / 2 (Tg − Te ) = dt RTI

(2-3)

where Te is the temperature of the thermal part of sprinkler head [deg C] Tg is the air temperature of near the thermal part of sprinkler head [deg C] u is fire-gas velocity of near the thermal part of sprinkler head [m/sec] RTI is the response-time index of sprinkler head [m1/2 sec1/2] The air temperature and gas velocity near the sprinkler head were calculated using the following equations as a function of heat release rate and position for steady-state fires by Alpert [4]. 2/3 5/3  (r / H ≤ 0.18) 16.9(Q / H )　　　　　　 ∆Tg =  −2 / 3 2/3 5/3  (r / H > 0.18) 5.38(Q / H )(r / H ) 　　

(2-4)

 (r / H ≤ 0.15) 0.95(Q / H ) 　　　　 u= 1/ 3 1/ 2 5/6  (r / H > 0.15) 0.20Q H / r 　　

(2-5)

1/ 3

where Q is heat release rate [kW] H is ceiling height [m] r is horizontal distance from fire source [m] ∆Tg is temperature rise near ceiling [deg C] (Horizontal distance r from fire source, ceiling height is H) Q is defined as Q=αt2 (α=0.5004: based on Chapter 2.1), it goes up until the sprinkler system activate. The detecting conditions of the closed type sprinkler head which we adopted are shown in Table 2.1.. Table 2.1. Calculation conditions of the activation time of the sprinkler Items Detecting temperature of thermal point of sprinkler head [degC] Horizontal distance from fire source to sprinkler head [m] (Effective water-sprinkled radius of high-sensitive sprinkler head) Response-time index of sprinkler head [m1/2sec1/2] Ceiling height [m]

20

Value 72 2.6 67 2.65


The thermal point temperature Tg［deg］

・Results of calculation The result of the activation time of sprinkler system is shown in Figurer2.4. As shown in this figure, the activation time is 59sec, and the heat release rate is 1742kW at that time. Based on the above data, we supposed the maximum heat release rate Qmax is equal to 2MW when the sprinkler system is activated. 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0

▼Nominal Activation Temperature = 72 [deg.] 59sec（Heat Releace Rate Q＝1,742kW） 0

30

60

90

120

150

180 Time［sec］

Case:α=0.5004 RTI=67

Figure2.4. Activation time of sprinklers

REFERENCES 1. I. Yuka, Y. Jun-ichi, D. Yoshikazu, N. Daisuke, T. Takayoshi, “Study on reliability of sprinkler system for evacuation safety method”, Architectural Institute of Japan, Summary of Technical Papers of Annual Meeting, 2012, pp.27-30. 2. Heskestad, . G., and Smith, H. F., “Investigation of a New Sprinkler Sensitivity Approval Test: The Plunge Test, Factory Mutual Research”, FMRC Serial No.22485 RC 76-T-50 December 1976 3. Bill, R. G.., “Thermal Sensitivity Limits of Residential Sprinklers”, Fire Safety Journal 21, pp.131-152 1993 4. Alpert, R.L., “Calculation of Response Time of Ceiling-Mounted Fire Detectors”, Fire Technology, Vol. 8, pp.181-195 1972

21


CHAPTER3 SMOKE ANALYSIS 3.1.1 Smoke Control Strategy The problems to be solved by smoke control and evacuation strategy in this residential BLDG are as follows; 1) A lot of smoke from the residential unit as fire origin 2) Delay of starting evacuation during the residents are sleeping 3) Diversity of residents (for example, Handicapped, Elderly, AirBNB users, et al.) To solve these problems, it is important to prevent smoke leakage from a residential unit and to secure the safety of evacuation routes for a long time. Therefore, we proposed the following smoke management devices and system; 1) Fire compartment between residential units and an evacuation route. ➢Fire compartment can prevent flame and smoke from leaking into the evacuation route. 2) Installing the pressurization smoke control system in the stairs and EV shafts of lower floors. ➢Pressurization to the vertical opening (i.e. EV shaft and stairs) can prevent smoke diffusion into stairs. 3) Planning a light court on the upper floors. ➢With a light court , residents on upper floors can evacuate through safe area open to outside. 4) Providing a bottom opening to the light court. ➢Supplying fresh air from the bottom of a light court can efficiently exhaust smoke from a light court.

3.1.2 Verification method On the lower floors, we calculate the volume of pressurized air supply and make sure of the safety of the evacuation route. On the upper floors, we evaluate the safety of a light court (=evacuation route) using FDS models.

22


Area of installing the pressurization smoke control system Pressure relief route Light court (Open void)

Upper floors

Intermediate refuge floor Lower floors plan

Lower floors

Upper floors plan

Section

Figure3.1.Smoke management devices and system

23


3.2 Smoke Control Design on Lower Floors to Safeguard Occupants 3.2.1. Objective ・ Safeguard of occupants against smoke in corridor until the completion of floor evacuation．・ Occupants on a fire floor evacuate to vestibules or an elevator hall, then evacuate toward level 1 by staircases or elevators for usual use. ・ Safety against smoke in vestibules and elevator hall by mechanically supplied air to staircases or elevator shafts． 3.2.2. Smoke Control Equipment

Figure3.2. Smoke Control Equipment

Figure3.3.Pressure Release Opening Through Rescue Corridor

24


25


26


3.2.3. Evaluation of Smoke Insulation 1) Setup Condition a) Temperatures in the Fire Room and the Corridor The temperatures at the initial and the peak stages of fires are shown in Table 3.3. by reference to Appendix 1. Table 3.3. Temperatures to Set Air Supply Flow Rate

b) Rooms and Openings The model for the analysis is made up with fire floor and vertical spaces such as staircases, elevator shafts. The room conditions are shown in Table 3.4., the openings conditions in Table 3.5. Table 3.4. Room Conditions

Table 3.5 .Opening Conditions Opening Area

Space

Opening Flow Coefficient

Corridor − Fire Room

(CR)

0.9 ×

2.1 ×

Vestibule 1 − Corridor

(L1C)

0.9 ×

2.1 ×

Initial Fire Peak Fire Area[m2] 1.89 m2 [L] 1.0 ＝ 0.0700 [H] 0.3500 1.89 m2 [O] 1.0 ＝ 0.7000 [C] 0.0100

0.4 ×

0.5 ×

1.0 ＝

1.8 ×

2.1 ×

1.0 ＝

0.4 ×

0.5 ×

1.0 ＝

0.9 ×

2.1 ×

1.0 ＝

0.4 ×

0.5 ×

1.0 ＝

EV Hole − Corridor Vestibule 2 − EV Hole

Wide[m]

(HC) (LH)

Height[m]

Num.

0.20 m2 [C] 3.78 m2 [O]

0.0000 [O]

0.7000

0.7000 [C]

0.0100

0.20 m2 [C] 1.89 m2 [O]

0.0000 [O]

0.7000

0.7000 [C]

0.0100

0.20 m2 [C] 1.89 m2 [O]

0.0000 [O]

0.7000

0.7000 [H]

0.3500

1.89 m2 [O] 4.62 m2 [C]

0.7000 [H]

0.3500

0.0100 [C]

0.0100

4.62 m2 [C] 2.31 m2 [C]

0.0100 [C]

0.0100

0.0200 [C]

0.0200 0.7000

Staircase 1 − Vestibule 1

(SL1)

0.9 ×

2.1 ×

1.0 ＝


(SL2)

0.9 ×

2.1 ×

1.0 ＝

EV Shaft 1 − EV Hole

(EH1)

1.1 ×

2.1 ×

2.0 ＝


(EH2)

1.1 ×

2.1 ×

2.0 ＝

Fire Lift Shaft − Vestibule 1

(EL1)

1.1 ×

2.1 ×

1.0 ＝

2.5 ×

2.0 ×

1.0 ＝

1.0 ×

1.0 ＝

5.00 m [H] 4.00 m2

0.3500 [O]

4.0 × 0.3 ×

0.3 ×

1.0 ＝

0.09 m2 [O]

0.7000

Fire Room − Outdoor

(RO)

27

2


Table 3.5. Openings Condition Opening Area

Space

Opening Flow Coefficient

0.7 ×

2.1 ×

0.7 ×

2.1 ×

Initial Fire Peak Fire Area[m2] 1.47 m2 [O] 0.7000 [O] 0.7000 1.0 ＝ 1.47 m2 1.0 ＝

0.7 ×

2.1 ×

1.0 ＝

(Refuge Floor; Level 1)

0.7 ×

2.1 ×

1.0 ＝

Corridor − Outdoor

0.8 ×

0.5 ×

2.0 ＝

Corridor − Other Residence

0.9 ×

2.1 ×

7.0 ＝

Other Room − Outdoor

2.5 ×

2.0 ×

7.0 ＝

4.0 ×

1.0 ×

7.0 ＝

Corridor − Residence on Other Floors

0.9 ×

2.1 ×

8.0 ＝

Residence − Outdoor on Other Floors

2.5 ×

2.0 ×

8.0 ＝

Staircase 1 − Outdoor

Wide[m] (SO1)

(Refuge Floor; Level 1) Staircase 2 − Outdoor

(SO2)

Height[m]

Num.

1.47 m2 [O] 1.47 m2 0.80 m2 [O] 13.23 m2 [C]

1.0 ×

0.7000

0.7000 [O]

0.7000

0.0100 [C]

0.0100

35.00 m2 [C] 28.00 m2

0.0010 [C]

0.0010

15.12 m2 [C] 40.00 m2 [C]

0.0100 [C]

0.0100

0.0010 [C]

0.0010

0.7000 [O]

0.7000

8.0 ＝

32.00 m2 7.68 m2 [O] Corridor − Outdoor on Refuge Floor 1.6 × 2.4 × 2.0 ＝ * Flow Coefficient : [O] Open, [C] Close, [H] Half Open, [L] A Little Open; 10 cm Wide 4.0 ×

0.7000 [O]

c) Air supply flow Rate Air supply flow rate is shown in Table3. 6 .by reference to Appendix 1. Table 3.6. Setting Air Supply Flow Rate

d) Modeling for Analysis The analysis tool is unsteady one layer model 1). The fire sources are shown in Table3. 7. by reference to chapter 2. The floor of fire origin is Level 2 under stack effect in winter. Table 3.7. Fire Sources and Openings Condition

28


2) Results and Discussion a) Case 1 Smoke does not flow into a corridor if the door of a fire room opens in 10 cm wide.

Figure3.4. Flow Balance of Case 1 b) Case 2 Case 2 is similar to Case 1. Until floor evacuation is completed, safe evacuation route is secured, because smoke does not flow into a corridor.

Figure3.5. Flow Balance of Case 2

29


b) Case 3 Air supply flow rate is low and smoke flows into a corridor temporarily, if the doors of vestibule and staircase are closed after the end of floor evacuation. However, air supply flow rate is high and smoke does not flow into a corridor, if the doors of vestibule and staircase are opened during firefighting activities.

Figure3.6.Flow Balance of Case 3a

Figure3.7. Flow Balance of Case 3b

30


3) Conclusion By the vertical space of pressurized smoke control system, smoke does not flow into a corridor until the end of floor evacuation, and smoke does not flow into the vertical space permanently. By this reason, not only staircases but also elevators can be used for evacuation. If firefighters open the doors of staircases and vestibules to enter the fire floor, it is better to increase air supply flow rate.

31


3.3 Fire safety design on upper floors 3.3.1 Fire scenario If a fire occurs in a residential unit on upper floors, the following 3 fire scenarios are assumed. First, whether sprinkler system works or not. Second, whether the fire compartment is formed or not. If sprinkler system works (S1) or fire compartmentation is succeeded (S2), evacuation route can be secured. Therefore, we chose the condition that sprinkler does not work and with failure of fire compartmentation (S3) for our evaluation. S1 Fire

Succeed in extinguish

Sprinkler works S2 Sprinkler doesn’t work

Prevention of smoke invasion to evacuation route

Succeed in compartmentation control S3 Fail in compartmentation

S3

Is this a safety scenario?

Figure3.8. Fire Scenario on upper floors 3.3.2 Tenability Criteria Since the light court has an opening at the top and bottom to the outside, the smoke from the residential unit of the fire origin could be efficiently discharged. However, if a lot of smoke is discharged the fire residential unit, it might threaten safety of evacuees. Therefore, under the condition that sprinkler does not work and with failure of fire compartmentation, we evaluate the following point necessary for evacuation safety. To evacuate without being exposed to toxic smoke If evacuees are exposed to smoke, it is necessary to consider hazard of smoke. The criterion are as follows. - Hazard of smoke Extinction coefficient Cs [1/m] ≤ 0.5 [1/m] *1(Reference Height =1.8 [m]) Toxic gasses CO2 [%] ≤ 0.5 [%] *2 Smoke temperature Ts [deg C] ≤ 44.8 [deg C] (Reference Height =1.8 [m]) *3 *1 Evacuees cannot keep their eyes open in thicker irritant smoke over 0.5 [1/m]1) *2 General evaluation criteria used in Japan2) *3 Pain from the application of heat to the skin occurs when the skin temperature at a depth 0.1 [mm] reaches 44.8 [deg C] 3)

32


3.3.3 Simulation models 1) FDS models and mesh The calculation area is over 19th floor, and calculation time is 600sec. In addition, to consider the spreading to outside and the reflux to the light court, the model includes the outdoor space at the top and side area of the building. Smoke exhaustion Reflux

Outside

20th~30th floor

Fire room

Cell size[unit:m] 1.5×1.5×1.5

Light Court 0.5×0.5×0.5 Fire room 0.125×0.125×0.125

Air supply

19thfloor

0.5×0.5×0.5

Outside Light Court Residence

Window OP1:W3.0 m×h2.0m OP2:w4.0m×h1.0m OP3:w3.0m×h2.0m Door Fire room

OP1

OP3

Door w0.2m×h2.0m (*)

OP2

Bottom open W1.5m×h22.5 m

Plan

Section

Figure3.9. FDS models and mesh

33


For the condition, that the fire compartment is not formed, it is assumed that the door is opened in 30 cm wide. For example, a shoe is caught in the door, or the door is damaged by fire, et al. When the door opening is 30 cm wide, flow coefficient α is calculated as follow4). When the door width is 90 cm and the opening is 30 cm, the opening angle is 18 deg. α B= (0.0061θ + 0.11) B= (0.0061×18 + 0.11) × (0.9) ≈ 0.2 m 30cm 18

o

Fire room

B : Opening width [m]

α :Flow coefficient [-]

Flow coefficient

90cm

θ :Opening angle[ ]

Opening angle

Figure3.10 .Flow coefficient α when opening the door 2) Fire origin -Fire roomThe fire room is assumed to be one room (Residence 5) on the 20th floor. Because Residence 5 has the smallest area, so air temperature of the room in case of fire assumed to become the highest of all. -Heat release rateThe fire origin is determined by the amount of fire load such as the combustibles and the interior material (wall and ceiling) of the residential unit.5) Heat release rate per unit shall be 703kW/m2. The derivation method is as follows. Afuel = 0.242 wload 1/3 Ar qr = Afuel qwood / Ar = 0.242 wload 1/3 qwood = 0.242 × (720)1/3 × 122= 265 [kW/m2] Then the heat release rate of the interior materials is added to this result. Calculation using the heat release rate per surface area of wood (122kW/m2) is as follows. q= 703 [kW/m2] {265 + 122(2 Ar + H c Lc ) / Ar } = Afuel : surface area [m 2 ] Ar :Room area [m 2 ] H c :Height of ceiling [m] Lc :Length of the wall [m] qr : Heat release rate per unit floor area [kW/m 2 ] qwood : Heat release rate per surface area of wood [kW/m 2 ] wload : fire load of residence [=720MJ/m 2 ]

34


3) Vents The parameters for open vents are shown in Table 3.8. Tabel 3.8.Parameter of open vent Doors Windows

Size (wide × height) 0.2m×2.0m 3.0m×2.0m 4.0m×1.0m 3.0m×2.0m

Conditions The door could not be closed by shoes The windows were broken by fire and hot smoke after F.O

4) Measurement Some devices are installed at the height of 1.8m from each floor level. The position of each device is as follows. Temperature: 28 places each floor (21FL+1.8m – 30FL+1.8m Total 280 places) Coefficient: 14 places each floor (21FL+1.8m – 30FL+1.8m Total 140 places) Carbon dioxide concentration: 14 places each floor (21FL+1.8m – 30FL+1.8m Total 140 places) Temperature

Temperature/Coefficient/CO2

H1 H2 H3 H4 H5 H6 H7 H8

30FL+1.8m 29FL+1.8m

G1 F1 E1 D1

G8 F8 E8 D8

C1 B1

C8 B8

28FL+1.8m 27FL+1.8m 26FL+1.8m 25FL+1.8m 24FL+1.8m 23FL+1.8m

A1 A2 A3 A4 A5 A6 A7 A8

22FL+1.8m 21FL+1.8m

Figure3.11. Measurement position

35


3.3.4 Simulation Results and Discussion 1) Smoke behavior

60sec 300sec Figure3.12.Change of smoke behavior

600sec

2) Result of measurement Temperature

CO2 concentration

Coefficient

ROOF ROOF b a l co n y R E S ID E N C E 　１

b a l co n y

b a l co n y ROOF

b a l co n y

： 1 00 ㎡ R E S ID E N C E 　１ R E S ID E N C E 　２

b a l co n y

b a l co n y

： 1 00 ㎡

： 8 ０㎡

b a l co n y

R E S ID E N C E 　２ R E S ID E N C E 　１

： 8 ０㎡

b a l co n y

b a l co n y

： 1 00 ㎡ R E S ID E N C E 　２

C o r ri d o r 　2 ２ 0 ㎡　

R E S ID E N C E 　３

： 8 ０㎡ C o r ri d o r 　2 ２ 0 ㎡　

b a l co n y ： 1 10 ㎡


b a l co n y C o r ri d o r 　2 ２ 0 ㎡　

： 1 10 ㎡


b a l co n y

L I G HT C O U RT

： 1 10 ㎡ L I G HT C O U RT b a l co n y

ROOF

L I G HT C O U RT

b a l co n y

ROOF B R I GE B R I GE

b a l co n y

ROOF EEV

付室1 １０

E V HA L L ROOF

B R I GE

EEV

付室1 １０

b a l co n y

E V HA L L ROOF

b a l co n y

DS 20

DS

E V HA L L ROOF

20

b a l co n y DS

L I G HT C O U RT

R E S ID E N C E 　6

EEV

付室1 １０

20

： 1 10 ㎡

L I G HT C O U RT


b a l co n y

： 1 10 ㎡

b a l co n y L I G HT C O U RT

R E S ID E N C E 　6 ： 1 10 ㎡ R E S ID E N C E 　5 ： 8 0㎡

R E S ID E N C E 　4 ： 1 00 ㎡

R E S ID E N C E 　5 ： 8 0㎡

b a l co n y

R E S ID E N C E 　4 ： 1 00 ㎡

b a l co n y b a l co n y

b a l co n y

R E S ID E N C E 　5 ： 8 0㎡

b a l co n y

R E S ID E N C E 　4 ： 1 00 ㎡

b a l co n y

b a l co n y ROOF


b a l co n y ROOF

ROOF

20F+1.8m(600sec)

20F+1.8m(600sec)

ROOF

b a l co n y

b a l co n y R E S ID E N C E 　１

20F+1.8m(600sec)

ROOF

ROOF

b a l co n y

R E S ID E N C E 　１

b a l co n y

b a l co n y

b a l co n y

b a l co n y


： 1 00 ㎡

： 1 00 ㎡

： 8 ０㎡

C o r ri d o r 　2 ２ 0 ㎡　

C o r ri d o r 　2 ２ 0 ㎡　



C o r ri d o r 　2 ２ 0 ㎡　

b a l co n y

b a l co n y

L I G HT C O U RT

b a l co n y

ROOF

b a l co n y

b a l co n y

ROOF B R I GE

B R I GE

EEV

： 1 10 ㎡

L I G HT C O U RT

ROOF

付室1 １０

E V HA L L ROOF

b a l co n y

B R I GE

EEV E V HA L L

付室1 １０

ROOF b a l co n y


b a l co n y

R E S ID E N C E 　5 ： 8 0㎡

ROOF

20

L I G HT C O U RT b a l co n y

R E S ID E N C E 　5 ： 8 0㎡

ROOF

b a l co n y

b a l co n y

： 1 10 ㎡

b a l co n y

R E S ID E N C E 　4 ： 1 00 ㎡

b a l co n y

b a l co n y

b a l co n y

L I G HT C O U RT


： 1 10 ㎡

R E S ID E N C E 　4 ： 1 00 ㎡

b a l co n y

E V HA L L

DS

20

20

L I G HT C O U RT

EEV

b a l co n y DS

DS

： 1 10 ㎡


b a l co n y ： 1 10 ㎡

： 1 10 ㎡

L I G HT C O U RT


b a l co n y

R E S ID E N C E 　２

： 8 ０㎡

： 8 ０㎡

付室1 １０

b a l co n y

： 1 00 ㎡ R E S ID E N C E 　２


R E S ID E N C E 　5 ： 8 0㎡


b a l co n y

ROOF

R E S ID E N C E 　4 ： 1 00 ㎡

ROOF

26F+1.8m(600sec) 26F+1.8m (600sec) 26F+1.8m (600sec) Figure3.13. Change of measurement result (horizontal direction)

36


Temperature (600sec) ×10-4

CO2 concentration (600sec)

Coefficient (600sec) Figure3.14.Change of measurement result (vertical direction)

37


Height from the 21FL [m]

30 25 20 15 10 5

0 20.0 A8 A7 A4 A3

46.2 25.0 A6 A5 A2 A1

30.0

35.0

40.0

45.0


25 20 15 10 5 91.0

0 20.0 25.0 G1 G8 F1 F8 E1 E8

30.0

35.0

A8 A4 H8 D8

30 25 20

A7 A3 H6 D1

45.0

50.0

A6 A2 H3

Criteria:0.5%►

5 0 0.0000

0.0010

0.0020

0.0030

15 10 5 25.0 H6 H5 H2 H1

30.0

35.0

0.0040

Carbon dioxide concentration[kg/kg]

50.0

45.0

50.0

25 20 15 10 5

91.0 30.0

35.0

40.0

Temperature[degC]

A8 A4 H8 D8

30 25 20

A7 A3 H6 D1

A6 A2 H3

A5 A1 H1

15 10

Criteria:0.5m-1►

5 0.1000

0.2000

0.3000

Coefficient[m-1]

Figure3.15. maximum of measurement result

38

45.0

Criteria:44.8degC ►

30

0 0.0000

0.0050

40.0

Temperature[degC]

35

A5 A1 H1

15 10

20

0 20.0 25.0 D8 B1 C1 D1 E1 B8

Temperature[degC]

35


40.0

25

35


30


30

0 20.0 H8 H7 H4 H3

50.0

Temperature[degC]

35 Height from the 21FL [m]

35




35

0.4000

0.5000


3.3.5 Discussion ➢Small amount of smoke is spread into the light court from the opening of the door. The area just above the fire room is contaminated with dense smoke, but it does not spread throughout the light court. ➢At the point just above the fire room, the air temperature exceeds the criteria slightly (44.8>46), but in other places all the criterion are satisfied. Therefore the safety route for evacuation is secured. In addition, even if the residents above the fire room could not evacuate through the door to corridor, they can evacuate through the adjacent room (see the right bottom in Figure 3.16.). High Temp 46.2degC

A range with a small amount of smoke

Slab of corridor

Smoke

Fire room Opening Light Court Light Court

Outside Residence

ROOF

ROOF

b a l co n y

b a l co n y R E S ID E N C E 　１

b a l co n y

b a l co n y


b a l co n y

b a l co n y

： 1 00 ㎡

： 1 00 ㎡



： 8 ０㎡

： 8 ０㎡

C o r ri d o r 　2 ２ 0 ㎡　

C o r ri d o r 　2 ２ 0 ㎡　



b a l co n y

b a l co n y

： 1 10 ㎡

： 1 10 ㎡

L I G HT C O U RT

L I G HT C O U RT

b a l co n y

ROOF

b a l co n y

ROOF

B R I GE

付室1 １０

B R I GE

EEV

付室1 １０

E V HA L L

EEV E V HA L L ROOF

ROOF b a l co n y

b a l co n y

DS

DS

20

20

A range with a small amount of smoke

L I G HT C O U RT

R E S ID E N C E 　6 ： 1 10 ㎡

b a l co n y

Fire room R E S ID E N C E 　5 ： 8 0㎡

L I G HT C O U RT

R E S ID E N C E 　6 ： 1 10 ㎡

b a l co n y

R E S ID E N C E 　5 ： 8 0㎡

R E S ID E N C E 　4 ： 1 00 ㎡

R E S ID E N C E 　4 ： 1 00 ㎡

b a l co n y


b a l co n y

b a l co n y

b a l co n y

ROOF

ROOF

Figure3.16.Detail of results

39

Horizontal evacuation


REFERENCES 1) The Society of Fire Protection Engineers (SFPE), “Chapter 61 Visibility and Human Behavior in Fire Smoke”, SFPE Handbook of Fire Protection Engineering 5th Edition, p2190, (2015) 2) Architectural Institute of Japan, “Chapter 3 Fire Safety of a Building”, Bouka Zairyou Pamphlet (in Japanese) (Pamphlet of Fireproof materials) ,1993, p81 3) The Society of Fire Protection Engineers (SFPE), “Chapter 63 Assessment of Hazards to Occupants from smoke, Toxic, Gases, and Heat”, SFPE Handbook of Fire Protection Engineering 5th Edition, p2376, (2015) 4) M. Hirota, K. Matsuyama, T. Yamana and T. Wakamatsu, ”Basic Properties of Intermediate Open Doors for Predicting Pressure Differences Between Rooms During a Smoke Control” , J. Environ. Eng., Architectural Institute of Japan, No.602, 2006, pp.1-8 5) K. Aburano, H. Yamanaka, Y. Ohmiya, K Takahashi, T. Tanaka, and T. Wakamatsu, ”Survey and Analysis on Surface Area of Fire Load” ,J. Archit. Plan. Environ. Eng., Architectural Institute of Japan, No.483, 1996, pp.1-8

40


CHAPTER 4 EVACUATION PLANNING

4.1 Objective The objective of evacuation planning is to secure life safety of occupant considering the characteristics of various kinds of occupants; such as permanent residents, vulnerable persons and gig persons, etc.

4.2 Strategy 1) Basic strategy: Stay put in your compartment The walls of each residence are composed of CTL and slabs are composed of hybrid of CLT and inflammable materials. Therefore this building’s basic evacuation policy is “stay put in one’s residential compartment”. However gig persons are expected not to understand above evacuation policy, therefore we also consider the possibility that gig persons start evacuation immediately after they hear fire alarm and they will try to use daily use elevator for evacuation. If a fire propagates to another compartment or fire situation becomes unexpected condition, occupants are ordered to evacuate by emergency broadcasting. 2) Use elevators for occupant evacuation considering We consider the elevator usage for evacuation for following reasons; - Vulnerable persons who cannot descend stairs - Gig persons who do not understand this building’s evacuation policy of phased evacuation through yearly evacuation drills. 3) Phased evacuation To prioritize the evacuation from fire floor, especially using elevators, we propose optimal zoning and timing of emergency broadcasting.

4.3 Assumed evacuation scenario 1) A fire occurred at one residential compartment, fire alarm rings. Part of the occupants at the fire floor; part of the resident and gig persons who do not understand this building’s evacuation policy of stay in put start evacuation. 2) Those of them assumed to use daily use elevator for evacuation. In consideration of this elevator usage, daily use elevators are in evacuation mode. In this mode, those elevators are only called and stop at the fire floor for certain period of time. This time period is decided later calculations.

41


3) Even if there are few waiting people at EV lobby when an elevator car arrived, they will take elevator without waiting other people’s arrival as a conservative assumption (It would be more effective if they wait following evacuees to take the elevator). If there are many waiting people at EV lobby when an elevator car arrived, elevator car is used full capacity. 4) We provide signage for EV lobbies to inform the evacuees the status and estimated waiting time, etc. We also provide information to ask them to take priority to vulnerable persons and wheelchair users. Providing those information, we expect to naturally being adjusted among evacuees who use elevators and who descend by stairs. 5) Fire-fighting EV is intended to be used by fire-fighters. Therefore, it cannot be operated by usual occupants (Except disaster management staff). However, when evacuation mode of daily use EVs finished, evacuees who cannot descend stairs such as wheelchair users wait at the firefighters EV lobby for rescue.

4.4 Setting of elevator evacuation 4.4.1 Daily use elevators / Occupant evacuation elevators 1) All of four daily use elevators are used as occupant evacuation elevators. Size of each elevator car is 1,400mm x 1,400mm. Capacity of those cars is 11 ordinary persons and 1 wheelchair user and 2 attendants (or ordinary persons) 2) Composition of lower elevators and upper elevators are shown in Figure.4.1.

42


30F 29F

27F

25F

23F

21F

19F

16F

13F

10F

7F

4F

1F B1F

Figure4-.1. Composition of daily use EVs / evacuation mode usage EVs and distribution of elevator doors 43

Intermediate refuge floor


4.4.2 Signage boards and operation of occupant evacuation elevators Signage boards are settled elevator halls and corridors of every floor. 1) When fire occurs and fire signal is sent to disaster management board, “evacuation EV mode” is activated. 2) In this mode, call of elevator car from fire floor is prioritized to those of from other floors. Number of priority is 6 times at upper floors and 10 times at lower floors. This number is decided by later calculation. 3) When elevator car is called from the fire floor and there is(are) occupant(s) in a car, the car descend to ground floor and getting off the all those occupants, it goes to fire floor. 4) After that, elevator car which is called from fire floor directly head to fire floor, without stopping other floors 5) Elevator descend from the fire floor does not stop other lower floors and stops ground floor 6) Signage boards provide following information of elevator operation status. Fire floor Car will arrive within 3 min. (depend on the floor) Priority : wheelchair users / 1 wheelchair per 1 car Priority : elderly, pregnant, physically disabled Maximum 11 persons per car (For pictures switch around) Non fire floors Car will arrive within 1, 3, 5, 10min. >10 min. Priority : wheelchair users / 1 wheelchair per 1 car Priority : elderly, pregnant, physically disabled Maximum 11 persons per car / Use staircase able-bodied persons (For pictures switch around) Image of signage are shown in Figure 4.2., 4.3., 4 .4.

44


Evacuation mode start

Figure 4.2.Signage of begining of evacuation mode

After pushing EV call button

Fire floor (priority mode) 1min, 2min, 3min Non-fire floors and fire floor of non-priority mode 1min, 3min, 5min, 10min, >10min

Figue4.3. Signage in the evacuation mode

45


After evacuation mode terminated

TERMINATED

Figure 4.4. Signage of after evacuation mode

4.5 Design calculation 4.5.1 Assumption of population 1) Number of total occupants 0.16 person/m2 based on the setting of verification method for building evacuation safety in Japan1), 2) Number of wheelchair users According to the survey on vulnerable children and persons2), number of physically disabled is 1,709,000 and this is 1.34% of total population concerning to demographic forecast3). Suppose wheelchair user is 50% of the physically disabled, percentage of physically disabled of the total population is 0.67% 3) Incoming and outgoing of elevator cars Able body evacuees We assume that those occupants specific flow is same to usual bottlenecks in buildings, specific flow is defined as 1.5 peoples/m/s. Consider the width of EV door of 0.8m, flow rate is 1.2 people/s Wheelchair users Based on the Tsuchiya’s experimental data4), time to incoming of one wheelchair user and one assistant person is defined as 5.58 s and outgoing of it is defined as 7.15 s.

46


From the settings of 1) and 2), distribution of evacuees is defined as Table 4.1. For conservative assumption, wheelchair users are located higher floors.

Table 4.1. distribution of evacuees Upper floors Floor Level

Floor

[m] 30 29 28 27 26 25 24 23 22 21 20

90 87 84 81 78 75 72 69 66 63 60

Expected Aarea of number of Occupants residence wheelchair users 2 [people] [people] [m ] 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 580 35 0.2345 385 2.5795 safety factor 1.25 3.224375

Allocation of wheelchair users [people] 1 1 1 1

Expected Aarea of number of Occupants residence wheelchair users [people] [people] [m2] 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 920 56 0.3752 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 920 56 0.3752 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1060 64 0.4288 1072 7.1824 safety factor 1.25 8.978

Allocation of wheelchair users [people] 2 2 2 1 1 1

one way travelling time

Door opeing time

[s] [s] 54.7619 53.04762 51.33333 49.61905 47.90476 46.19048 44.47619 42.7619 41.04762 39.33333 37.61905

Door closing time [s] 3 3 3 3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3 3 3 3

4

Lower floors Floor Level

Floor

[m] 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2

54 51 48 45 42 39 36 33 30 27 24 21 18 15 12 9 6

47

9

one way travelling time

Door opeing time

[s] [s] 34.19048 32.47619 30.7619 29.04762 27.33333 25.61905 23.90476 22.19048 20.47619 18.7619 17.04762 15.33333 13.61905 11.90476 10.19048 8.47619 6.761905

Door closing time [s] 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3


4.5.2 Setting of elevator Size of elevator car, maximum velocity, and acceleration rate are given by reference to similar scale of high rise apartment buildings in Japan. Details are shown in Table 4.2. Table 4.2. Settings of evacuation elevators Upper floor Lower floor Number of elevator Capacity

Size of elevator car Max. velocity Acceleration rate (increase) Acceleration rate (decrease)

2 11 ordinary occupants 1 wheelchair and 2 attendant 1,400mm x 1,400mm 2.5 m/s 0.75m/s2 -0.75m/s2

2 11 ordinary occupants 1 wheelchair and 2 attendant 1,400mm x 1,400mm 1.75 m/s 0.525m/s2 -0.525m/s2

4.5.3 Evacuation Scenario 4.5.3.1 Evacuation start time According to Nakano’s research5), evacuation start time after ringing of fire alarm is acquired as Figure.4.5. However this data is acquired as part of the training course of staffs of disaster control center, therefore this evacuation start time is thought to be earlier than usual occupant’s evacuation start time. Considering this aspect, we use this data applying safety factor of 2 for this design analysis. We approximate this evacuation start time curve by cumulative of log-normal distribution. This time curve is expressed as follows; N (t ) = ∫ f (t )dt t

0

f (t ) =

(

)

 log t − µ 2  1 exp−  2σ 2 2π σt  

μ=4.2, σ=0.6 N(t): Number of occupants who have start evacuation [people] (Orange line in Figure 4.5.) t: time [s]

48


We define the evacuation start time of evacuee n as follows; tstart(n) = talarm+ tdelay(n) talarm : time from fire occur to alarm rings [s] (=50 s : Estimated RTI calculation of sprinkler head. Consider that smoke detectors are installed in each room, this can be regarded as conservative assumption) tdelay(n): evacuation start time after ringing of fire alarm of evacuee n [s] tdelay(n) is acquired by the N(t) applying safety factor of 2 (Red line in Fig. 4-5) Nakano's data Approximation formula

Cumulative frequency

Approximation formula with safety factor 2 1.2 1 0.8 0.6 0.4 0.2 0 0

60

120

180

240

300

360

420

480

540

600

Time from alarm ringing to evacuation start [s]

Figure4.5.Cumulative frequency of evacuation start time acquired from training course of staffs of disaster control center

49


Calculation of activation time of heat detector in a residential unit The activation time of a heat detector is calculated by the equation shown in chapter 2.2 (Equation (2-3) - (2-5)). Calculation conditions of the heat detector are shown in Table 4.3. Table 4.3. Calculation conditions of the activation time of the heat detector Items Value Detecting temperature of thermal point of heat detector [degC] 70 Horizontal distance from fire source to heat detector [m] 5 1/2 1/2 Response-time index of heat detector [m sec ] 15 Ceiling height [m] 2.65


The result of the activation time of the heat detector is shown below. The activation time is 50sec, and the heat release rate is 1251kW at that time. 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0


30

60

90

120

150

180 Time［sec］


Figure4.6. Temperature rise of a heat detector and activation time

4.5.4 Calculation of elevator evacuation of fire floor Figure4.6. and 4.7. show the relation between evacuation start time, number of occupants who start evacuation and arrived at EV halls, and round trip time of EV cars. Roughly speaking, 4 min after alarm ringing, about 80% of occupants in the fire floor can have evacuated from the floor by elevators both in upper floors and lower floors. Therefore we set the 4 min priority of occupant elevator evacuation for the fire floor.

50


Upper floors Round trip time of 30F is about 120s There are two EV cars in upper floors Number of occupants in one upper floor is 35. Four floors among 11 upper floors have one wheelchairs users

Cumulative number of occupants who reached EV hall at fire floor


7

14

21

28

35

0

0.2

0.4

0.6

0.8

1

1.2

0 0 120 180

Approximation formula with safety factor 2

60

EV cars return to the fire floor. At this time, about 17 persons have arrived at EV lobby, two of them have already took elevators to ground floor. If a wheelchair user is not included, all of them can take elevator. Even if a wheelchair user is included, 14 persons including wheelchair user can take elevator.

240 300 360

When the third round EV return to the fire floor, more than 80% of occupants have arrived EV lobby, this means most of the occupant at fire floor can have evacuated from fire floor.

420 480


Assume conservatively both of two EV cars of upper floors are used by only one person.

540 600 Assumption that two EV cars arrive close time in early stage of evacuation thought to be conservative because if latter EV car is later, later EV can server more persons.

Therefore we set 6 times priority EV car calling from fire floor. After this priority, call from fire floor is treated as same as other floors.

Fig. 4.7. Relation between evacuation start time and round trip time of EVs at upper floors

51


Lower floors Round trip time of 18F is about 80s There are two EV cars in upper floors Number of occupants in one upper floor is 64 (some floors are 56). Three floors among 18 lower floors have two wheelchairs users

Cumulative number of occupants who reached EV hall at fire floor


0

12.8 25.6 38.4 51.2 64 1.2

1

0.8

0.6

0.4

0.2

0 0 120 180

Approximation formula with safety factor 2

60

EV cars return to the fire floor. At this time, about 16 persons have arrived at EV lobby, two of them have already took elevators to ground floor. Consider in same way of upper floors, most of the EV cars capacity can be used.

240 300

Third EV cars also can be high efficiency because about 18 persons have arrived after second EV car’s arrival

360 420

When fourth EV cars have arrived at fire floor, more than 80% of the occupants at the fire floor have arrived at EV lobby.

480


Assume conservatively both of two EV cars of upper floors are used by only one person.

540 600 Assumption that two EV cars arrive close time in early stage of evacuation thought to be conservative because if latter EV car is later, later EV can server more persons.

However consider the floors that have two wheelchair users, almost two anther EV cars are needed. Therefore we set 10 times priority EV car calling from fire floor. After this priority, call from fire floor is treated as same as other floors.

Fig4.8.Relation between evacuation start time and round trip time of EVs at lower floors

52


4.5.5. Evacuation start of other floors by emergency announcement considering evacuation EV operation From above examination of EV evacuation from fire floor, most of the occupants have evacuated from fire floor 4 min after ringing of fire alarm. Therefore if fire cannot be controlled within 5 min after fire alarm, emergency announcement which orders to evacuate to the ground is broadcasted by a staff of disaster control center. We also assume the variance of evacuation start time of non-fire floors as same as Nakano’s distribution. Consider that time origin of Nakano’s distribution is “fire alarm”, but in this situation the time origin is “emergency announcement” which is clearer information for evacuation start. Therefore this assumption thought to be conservative. After the 4 min priority of fire floor, EVs change to the next operation mode. In this mode, EVs can be called from non-fire floors. However, number of floors served by the EVs is large and the time interval from one EV car departure from a floor to next EV car arrival is about 10 min. For this purpose, we show the information on the signage that “Next EV car will come 10 min after” to promote the evacuees who can walk and descend staircase. The time that first EV car arrives and next EV car arrives are about 10 to 20 min, most of the occupants in the floor have started evacuation and arrived at EV hall (or descend to staircase) within this time interval. Therefore evacuees who cannot descend staircase like wheelchair users will have arrived and they will be able to evacuate by occupant evacuation elevator within this time interval. On the other hand, if evacuees wait next EV car, their evacuation time will excessively long. Therefore, occupant evacuation elevators serve only two times to each non-fire floors. After occupant evacuation elevator mode, the information signage shows “Use staircase”, “Wait fire-fighters lobby”. Also considering that lower floors (under the intermediate refuge floor : 19F) has many floors and number of occupants is large, and when fire occurred in upper floors, there is little urgent need to evacuate, upper area of the lower floors (10-18F) are prioritized the emergency announcement. On the other hand, upper floors and lower floors are served by different elevators. There is little need to change the timing of emergency announcement. Considering above aspect, timing of emergency announcement to lower floors of lower area (1-9F) is 10 min, which is 2 times as large as that of other floors. Figure4.9. shows the timing of emergency announcement by the fire floor. In total, evacuation time using elevators becomes about 30 min.

+4 min.

+4 min. after fire alarm

after fire alarm

+4 min.

after +4 min. fire alarm

+4 min.

+4 min.

+4 min.

8 min.

8 min.

Figure4.9.Timing of emergency announcement by the fire floor

53


4.5.6. Calculation of staircase evacuation 4.5.6.1. Number of evacuees who evacuate by staircase Occupants except who has evacuated by occupant elevators are assumed to evacuate by staircase. 4.5.6.2. Setting of flow rate According to Kadokura’s observation research of evacuation drill at high rise building of 25 stories6), flow rate around staircase is mainly governed by stairs itself and rotation behavior at landing etc., rather than staircase exit doors. Flow rate at stairs are 44.2-53.3persons/m/min. When width of stairs is 1.2m and width of staircase exit doors is 0.8m, practical flow rate at exit door is 55.3-66.6 persons/m/min. Therefore we used low rate at exit door is 50 persons/m/min as conservative assumption. 4.5.6.3. Consideration of evacuation behavior around staircase This building has two stairs at lower floors and one stair at upper floors, therefore, accumulation of evacuee will occurred at the intermediate refuge floor. And also consider the merging rate pointed by Sano et. al7), if simultaneous evacuation of all floors around staircase occur evacuees tend to remain at higher floor (unless merging rate is excessively high). Those aspects mean that last evacuee remain at the intermediate refuge floor, it is adequate to be the sum of travelling time from upper floors and passing through time of “staircase neck”. Figure4.10. illustrate above aspects. 23F 22F 21F

Evacuees at upper floors can quickly evacuate from floors because evacuees can easily flow out from the staircase at the intermediate refuge floor. Evacuees from upper floors accumulate at the intermediate refuge floor

20F (1-k)18Q

19F k(1-k)17Q

18F k(1-k)16Q

(1-k)17Q

17F k(1-k)15Q

(1-k)16Q

16F k(1-k)14Q

(1-k)15Q

15F (1-k)14Q

3F 2F

Q

Q

k : merge rate of the floor Q: Flow rate [people/s]

1F

Figure 4.10. Generation of accumulation around staircase

54


4.5.6.4. Calculation result of evacuation time We calculated staircase evacuation time by node-link network calculation method to consider the distribution of evacuees and variation of evacuation start time. Specific flow at the doors are defined as 1.5 people/m/s, velocity on flat area is defined as 1.0 m/s. If enough occupants are gathered at the door, flow rate at the door is defined by product of door width and specific flow of 1.5 people/m/s. On the other hand, product of door width and specific flow is larger than the flow rate of gathering to the door, flow rate at the door becomes flow rate of gathering to the door. To simplify the calculation, we divided the building into 7 zones, which is one zone of upper floor above intermediate refuge floor and 6 zones of lower floor (See Figure4.11.). And each zone is divided into 4 groups of evacuation start time (See Figure 4.12.).

Zone_Upper

Zone_16-18F Zone_13-15F Zone_10-12F Zone_7-9F Zone_4-6F Zone_2-3F

Figure4.11. Zoning for staircase evacuation calculation

55


1.2 Approximation formula with safety factor 2


1

Group D

0.8

Group C 0.6

Group B

0.4 0.2

Group A 0 0

60

120

180

240

300

360

420

480

540

600


Figure4.12.Grouping of evacuation start time

Calculation model is shown in Figure4.13. and calculation result is shown in Figure4.12. From the Figure 4.14., evacuation time controlled by staircase bottleneck is about 23.9 min. Adding the last evacuees walking time of 12 s/floor ×18 floor = 196 s, total evacuation time of staircase is 27.2 min. In above calculation, we assumed that elevator evacuation and staircase evacuation are conducted independently. However those evacuees will merge at the EV lobby at the ground floor and they flow out to the outside through the same route. Width of exit from EV lobby is enough to the flow, however automatic door at the entrance is a little narrow. Therefore additional evacuation door should be installed. (Figure 4.15.)

56


Travel distance in a residence [m] Travel distance to a staircase [m]

+4 min

Number of evacuees [people] Evacuation start time [s] Rate of evacuation start (See Fig. 4-11)

A B C D

Door width from upper floor staircase [m]

A Number of evacuee who pass through here [m]

B

Fire floor

C D

Sum of two stairs width [m]

Travel distance in staircase [m]

A B C

+4 min

D

A B C D A B C

+8 min

D A B C D A B Sum of two door width from staircase [m]

C D

Figure4.13. Staircase calculation model(Ex. Fire occurred at 16F) 57


Number of evacuees [people]

Evacuees who have entered the staircases, vestibule and corridor

Maximum number of evacuees in the staircases, vestibule and corridor

Evacuees who have get out the staircases Time [s]

Figure4.14. Evacuation completion time and evacuees distribution

From occupant EVs From staircase

From staircase

Additional exit considering simultaneous evacuation from occupant EVs and staircase

Figure. 4.15. Evacuation floor Fig. 4-15 Evacuationroute routeon on ground ground floor

58


4.6. Conclusion Above calculation, both of elevator evacuation time and staircase evacuation time is about 30 min. This evacuation time thought to be “conservative and most probable” evacuation time. If more evacuees use staircase instead elevator, total evacuation time become almost the same of above calculation because last phase of staircase evacuation, there are a few evacuees uses staircases, therefore increase of staircase use evacuee does not change the staircase evacuation time. Considering the fire resistant time of the CLT structure of 45 min, evacuation is completed before fire resistance limitation time.

Reference 1) Ministry of Construction: Building Evacuation, Notification No. 1442 of the Ministry of Construction (May 31, 2000), Establishment of calculation method etc, concerning the verification method for building evacuation safety 2) Ministry of Health, Labour and Welfare: Survey on difficulty over daily life on 2011 (Survey on vulnerable children and persons) 3) Ministry of Internal Affairs and Communications: demographic forecast (2011.10.1 present), 2012.4.17 4) Shin-ich, Tsuchiya, Yoko Furukawa, and Yuji Hasemi: Evacuation safety Planning Based on Behaviour Abilities of Disabled, Part. 7 Experiment for Getting in and out time of Elevator, and Disccuion of Queuing Area, Summaries of technical papers of annual meeting Architectural Institute of Japan, 2017.8 5) Mina Nakano and Ichiro Hagiwara: Experimental Study on Starting Time of Evacuation in Sleeping Condition, Summaries of technical papers of annual meeting Architectural Institute of Japan, 2000.9 6) Hiroyuki Kadokura, Ai Sekizawa, Tomonori Sano, Masanori Yajima, Satomi Masuda, Observational Survey of Downward Walking in Stairs at a Total Evacuation Drill in a Highrise Office Building Part.5, Analysis of Profile of Evacuation Flow in the Phased Evacuation Drill, Proceedings of JAFSE Annual Symposium 2012, pp.136-137, 2012.5 7) Tomonori Sano, Enrico Ronchi, Yoshikazu Minegishi, Daniel Nilsson, A pedestrian merging flow model for stair evacuation, Fire Safety Journal, Volume 89, pp. 77-89, 2017.4, https://doi.org/10.1016/j.firesaf.2017.02.008

59


CHAPTER 5 FIRE SPREAD AND FIRE RESISTANCE DESIGN 5.1 Horizontal fire compartmentation The wall between residences is planned to restrict horizontal fire spread as a gypsum board with fire resistance for 45 minutes. CLT is treated as layer of burning margin. (Figure5.1.) Therefore, this examination verifies only the prevention of the vertical spreading of fire.

CLT

Fire resistance for 45min

Gypsum Plaster board (12.5mm x 2)

Figure5.1. Design of burning margin 5.2 Compartment fire temperature In a compartment fires for one-zone, there will be an energy balance, which can be divided in very detailed processes. The typical energy balance explains that all energy that is released from the combustion Q will either transfer through the walls QW, leave the compartment as hot gases QE, radiate through the openings QR see, equation (5-1). An illustration of the energy balance is shown in Figure5.2.

Q = QW + QE + QR (5-1) Q : the total heat release rate in fire room [kW] QW : the heat lost rate of the wall, the floor and the celling [kW] QE : the loss rate due to the flow hot gases out of the compartment opening [kW] QR : the heat radiating out through the opening [kW]

60


Tf

QW

QW

Q

QE ms QR ma

QW

Figure5.2. Heat balance for a fire compartment Air and combustion products flow in and out of a fire compartment driven by buoyancy, i.e. the pressure difference developed between the inside and outside of the compartment due to temperature difference, as indicated in Fig. 5-1. The mass flow rates in ma and out ms must be equal. The mass flow rates through vents are computed by applying the Bernoulli’s principle. For openings the flow rate can be derived as approximately proportional to the opening area times the square root of its height. The value is approximately 0.5.

m = = (5-2) s m a 0.5 A op H op ms : the mass flow rate of the gases out of the compartment [kg/s] ma : the mass flow rate of the fresh air entering the compartment [kg/s] Aop : the size of vent opening [m2] Hop : the height of vent opening [m] Almost all common fuels produce approximately 3000 kJ/kg of air. If all the oxygen is consumed it has a ventilation-limited fire and the maximum possible energy release rate within the room is shown in equation (5-3).

Q = 3000 × ma = 3000 × 0.5 Aop H op = 1500 Aop H op

(5-3)

For the unsteady case, assuming a semi-infinite solid under a constant heat flux, the exact solution for the rate of heat conduction is shown equation (5-4) QW AW =

k ρc (T f − T0 ) t

(5-4)

where Tf : temperature in fire room [K] AW : the area of the wall [m2] k : thermal conductivity [kW/mK] c : detector element’s specific heat [kJ/kg-K] ρ : density [kg/m3]

61


The convection loss term is proportional to the mass flow times the fire temperature increase, i.e: (5-5) QE = c p (T f − T0 ) × ms cp : the specific heat capacity of the combustion gases(=1.01) [kJ/kg-K]

The heat radiating out through the openings may be calculated as:

QR σ Aop (T 4f − T04 ) = σ : Stefan–Boltzmann constant (=5.67 x10-11 kW/m2K4)

(5-6)

Part of the heat generated in the fire compartment contributes to the temperature rise in the fire compartment. The time change in the temperature rise in the fire compartment per unit time is shown in equation (5-7)

T= f (t +∆t )

T(t ) c p ρ∞T∞V

(Q + QW + QE + QR )

(5-7)

5.3 Control of Vertical Fire Spread A part of the combustible gas generated by pyrolysis in the fire compartment is discharged outside the compartment as an unreacted combustible gas and burns. Therefore, heat release rate of external flame is the value obtained by adding the heat release rate of the unreacted combustible gas to QE in equation (5-5)

Qex = QE + Qc = 0.5c p (T f − T0 ) Aop H op + 100 Aop H op

(5-8)

Qex : the heat release rate of external flame [kW] Qc : the heat release rate of the unreacted combustible gas [kW]

When the size of the opening is B/H2 the flame height from the opening is shown in equation (5-11). (5-11) Lc = 2.8( H / 2)Q *2 / 3

62


Q* = Q /( ρc pT∞ g 1 / 2 B( H / 2) 3 / 2 )

(5-12)

As shown in Fig.5-3, the flame ejected from the opening reaches the upper floor along the beam, the balcony and the handrail. The length of the flame that exerts the fear of spreading fire to the upper floor is shown in equation (5-13).

y1=1.55m L

Opening② Width: 2.5m Height: 2.0m

L’

y1=1.55m

L’=L-(y+x1+x2) Figure5.3. The flame ejected from the opening L ' = Lc − ( y + x1 + x2 )

(5-13)

Let us consider a calculation for the incident radiant heat flux caused by a fire to a remote target object such as depicted in Fig.5-3. The source of the radiation can be considered to be a flame at temperature Tflame. The radiant heat flux that is receives at a target a distance, y1, away will be reduced from that emitted by Tflame. A flame temperature is fixed at 1,093 K regardless of flame area. The fraction of energy reduced is depended to the configuration factor, designated by F. The heat flux received by the target object is shown in equation (5-14). The high of heating surface is used L’ (equation 5-13). 4 q = T flame σ Fε

q Tflame

σ

F

ε

(5-14) 2

: the heat flux due to radiation [kW/m ] : the flame temperature (=1,093) [K] :Stefan-Boltzmann constant ( = 5.67 x 10-11) [kg/m2K2] : configuration factor [-] : the flame emissivity (= 0.9) [-]

63


target

Offset distance =y1 Heating surface

a Height =L’

a

Figure5.4. Radiation to a target object from a flame The configuration factor is shown in equation (5-14). a b   X = y1 , Y = y1   X Y Y X  F = 4  + tan−1 tan−1  2 2 2  2π  1 + X 1+ X 1+ Y 1+ Y 2 

  

(5-14)

The limit value of fire spread due to radiant heat is expressed by equation (5-15) from the experimental result on the ignition time of wood such as ISO. t

∫ {q(t )}

2

dt < 120000

(5-15)

0

64


5.4 Modeling of heat release rate from openings when multi-floors burning When multi-levels are burning at the same time, heat release rate from openings become large. However, it is difficult to expect the property of multi-levels burning and that of heat release rate from openings, so in this case study, heat release rate is defined as sum of them from burning floors at the same time (Figure5.5.,5.6.).

i+2 階

i+2 階

i+2 階

Qi+1(t) i+1 階

i+1 階

i+1 階

Qi(t)

Qi(t)

Qi(t)

i階

12000 10000

i階

i階

Figure5.5.

Model of heat release rate considering upper floor fire spreading

upper floor fire spread

Qi(t)+Qi+1(t)

Q[kW]

8000 6000

Qi+1(t)+Qi(t)

Qi(t) Qi+1(t)

4000 2000 0

0.00

10.00

20.00

30.00

40.00

50.00

60.00

time[min] Figure5.6. Time history of heat release rate considering fire spread to above level

65


5.5 Validation cases If fire in a residential unit becomes fully-developed, external flame increases in length to floors above. If fire length becomes long and heat flux becomes high, directly above residential unit catches the fire. If it is repeated, multi-floors are burning at the same time, finally, it becomes conflagration. In our proposal, to prevent it, the fire spreading is suppressed within three floors in any cases. Three cases are validated as below based on phases of vertically fire spread (Figure5.7.). Phase-1: Only one floor is burning Phase-2: Two floors are burning at the same time (After vertically fire spread in Phase-1) Phase-3: Three floors are burning at the same time (After vertically fire spread in Phase-2)

Target

Target

Target

Case-1

Case-2

Case-3

Figure5.7. Verification case

66


5.6 Result of fire spreading time Phase-1: Only one floor is burning Floor directly above catches the fire at 39 minutes. 20,000 18,000 16,000 14,000

Q[kW]

12,000 10,000

𝑄𝑄𝑖 (𝑡𝑡)

8,000 6,000 4,000 2,000 0

0.00

10.00

20.00

30.00

40.00

50.00

60.00

time[min]

Figure5.8.

Time history of heat release rate

800 700

q2[(kW/m2)2]

600 500 400

𝑠𝑠2

∫𝑠𝑠1 𝑞𝑞 𝑡𝑡 2𝑑𝑡𝑡 =120000

39 [min]

300 200 100 0

0.00

10.00

20.00

30.00

40.00

time[min]

Figure5.9.

Integrated value of q2

67

50.00

60.00


Phase-2: Two floors are burning at the same time (After vertically fire spread in Phase-1) Floor directly above catches the fire after 44 minutes after the fire break out at the lowest floor

20,000 18,000

𝑄𝑄𝑖 (𝑡𝑡)+𝑄𝑄𝑖+1(𝑡𝑡)

16,000 14,000

Q[kW]

12,000 10,000 8,000 6,000 4,000 2,000 0

0.00

10.00

20.00

30.00

40.00

50.00

60.00

time[min]

Figure5.10.


800 700

q2[(kW/m2)2]

600 500 400

𝑠𝑠2

∫𝑠𝑠1 𝑞𝑞 𝑡𝑡 2𝑑𝑡𝑡 =120000

44 [min]

300 200 100 0

0.00

10.00

20.00

30.00

40.00

50.00

time[min]

Figure5.11.


68

60.00


Phase-3: Three floors are burning at the same time (After vertically fire spread in Phase-2) Floor directly above catches the fire after 46 minutes after the fire break out at the lowest floor.

20,000 18,000

𝑄𝑄𝑖 (𝑡𝑡)+𝑄𝑄𝑖+1(𝑡𝑡)+𝑄𝑄𝑖+2(𝑡𝑡)

16,000 14,000

Q[kW]

12,000 10,000 8,000 6,000 4,000 2,000 0

0.00

10.00

20.00

30.00

40.00

50.00

60.00

time[min] Figure5.12.


800 700 600

q2[(kW/m2)2]

500 400 300

46 [min]

𝑠𝑠2

∫𝑠𝑠1 𝑞𝑞 𝑡𝑡 2𝑑𝑡𝑡 =120000

200 100 0

0.00

10.00

20.00

30.00

40.00

50.00

time[min] Figure5.13.


69

60.00


Therefore, fire spread can be suppressed within three levels in 45 minutes. However, it has few allowance of safety. In case of burning on many levels at the same time, it will be faster and faster to spread next upper levels. The results of fire spreading calculation are shown below. Especially, in case of burning three floors and over at the same time, next upper floor catches fire in 2 minutes. So, we propose fire resistance design for additional safety. Table5.1. Vertical fire spread time Number of floors Vertical fire spread time from Vertical fire spread time from spreading fire fire breaking out previous level catching fire 1 39.0 min 2 46.5 min 7.5 min 3 48.3 min 1.8 min 4 49.7 min 1.4 min 5 50.8 min 1.1 min ・・・ 5.7 Fire resistance vertical design Our proposals for vertically fire spread are like below. (1) Facade is set back 2.65 meters every three floors (lower floors) (2) Facade is set back 2.65 meters and 5.1 meters every other span (upper floors)

70


(1) Facade is set back 2.65 meters every three floors (lower floors) In lower floors, faced is set back 1.55 meters in regular floor for the space of balcony, in addition, facade is set back 2.65 meters every three floors (it is called “set-backed floor”) for prevention of vertically fire spread.

setback 1.55m

y1=2.65m

2.65m

L’

L

Set-backed floor

Set-backed floor

x2=1.1m x1=0.3m

2.65m

Opening② Width: 2.5m Height: 2.0m

y1=1.55m

Set-backed floor

L’=L-(y+x1+x2) Figure5.15.



Figure5.14.

Set-backed floor

Lower floors section

1.55m

2.65m

Figure5.17. Set-backed floors plan in lower floors

Figure5.16.Regular floors plan in lower floors

71


Validation cases Three cases are validated as below to make sure the effect of set-backed floor for prevention of vertically fire spread (Figure5.18.). Case-A: Fire break out at a floor directly below set-backed floor Case-B: Fire break out at two floors below set-backed floor Case-C: Fire break out at set-backed floor

Set-backed floor

Set-backed floor

Set-backed floor

Target

Target

Target

Set-backed floor

Set-backed floor

Set-backed floor

Case-A

Case-B

Case-C

Figure5.18.

Verification case

72


Result of fire spreading time Case-A: Fire break out at a floor directly below set-backed floor Floor directly above catches the fire after 112 minutes after the fire break out at the lowest floor 100 90 80

q2[(kW/m2)2]

70 60 50

𝑠𝑠

∫𝑠𝑠 𝑞𝑞 𝑡𝑡 2𝑑𝑡𝑡 =120000

112 [min]

40 30 20 10 0

0.00

20.00

40.00

60.00

80.00

100.00

120.00

time[min]

Figure5.19.


Case-B: Fire break out at two floors below set-backed floor Floor directly above catches the fire after 59 minutes after the fire break out at the lowest floor 800 700

q2[(kW/m2)2]

600

59 [min]

𝑠𝑠

∫𝑠𝑠 𝑞𝑞 𝑡𝑡 2𝑑𝑡𝑡 =120000

500 400 300

Fig. Integrated value of q2

200 100 0

0.00

10.00

20.00

30.00

40.00

50.00

60.00

time[min]

Figure5.20.


Case-C: Fire break out at set-backed floor Floor directly above didn’t catch the fire because flame didn’t increase in length over solid baluster. As above, set-backed floor can suppress vertically fire spread.

73


(2) Facade is set back 2.65 meters and 5.1 meters every other span (upper floors) In upper floors, two types of plan are designed and these plans set odd floors and even floors respectively. Both of their faced is set back every other span; 2.65 meters and 5.1 meters, but the position of set-back is different. For example, a residence has 2.65 meters set back facade, directly above and below residence has 5.1 meters set back. Through validation of Case-A to Case-C in lower floors, 2.65 meters set-backed floors can suppress vertically fire spread. In upper floor, in addition, offset distance is longer than it to set back every other span. The risk of vertically fire spread becomes even less.

2.65m 5.1m 2.65m 5.1m

Figure5.21.

Upper floors section

2.65m

5.1m Fig.5-22 Even floors plan in upper floors

5.1m

2.65m Figure5.23. Odd floors plan in upper floors

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CHAPTER 6 EFFECTIVE FIREFIGHTING PLAN

6.1 Objective of Firefighting The main objective of firefighting at the fire site is to protect the life of occupants, prevent the building from being damaged by fire, and prevent spread fire to adjacent buildings.

6.2 Building performance requirements Performances required to buildings for safe and effective firefighting are: (1) Protection of a staging area for firefighting and rescue activity until the end of fire. (2) Safe and easy access to the location of fire origin and other places where firefighting and rescue activity are necessary.

6.3. General Planning and Firefighting Scenarios 6.3.1 Facilities and equipment for firefighting Table 6.1. shows the facilities and equipment in the case study building, which meet the requirements described in section 6.1. Sprinkler system is equipped in whole of the building. Therefore fires are expected to be extinguished or restrained without fire-fighter’s activities. Following fire-fighter’s activity is for the worst scenario of sprinkler failure.

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Table 6.1. Firefighting Facilities and Equipment in the Case Study Building Required Facilities and Purpose Performance Equipment Safety protection Vestibules To provide staging areas for firefighting and of firefighting connected to rescue activity. staging area staircases Smoke control To prevent smoke from propagating to firesystem fighters lobby, EV hall, and EV shafts. Staircases are also protected by those compartments. To protect occupants and firefighters from hot and dense smoke. There are no smoke control system in each residential compartment Automatic To prevent fire spread from the residential Safe & easy access sprinkler system compartment of fire origin to other to the location of compartments. fire origin To suppress fire to the degree that fire brigades can extinguish. Fire stand pipe and To supply firefighting water from fire piping system for engine to higher floors. fire brigade use To send water to sprinkler system from fire engine. Automatic fire To collect fire information swiftly. alarm system A control panel is equipped in the Emergency Control Center on ground floor.

6.3.2 Firefighting scenarios (1) Receiving a fire call. Fire brigades recognize a fire accident in the building by receiving a call from building occupants. (2) Arrival at fire site. The fire engines arrive at the fire site. We assumed the arrival time of the fire engines from a fire station to the fire site as 5 minutes or shorter referring to the rule of deployment of firefighting resources enacted by Tokyo Fire Department. (3) Access to the floor of fire origin. Fire engines halt near the entrance of the building. Firefighters approach the floor of fire origin via firefighting elevator. Table 6.2. shows the timetable of firefighting scenario from notification to arrival at fire origin. Figure. 6.1 shows the approach routes into the building. A group of firefighters approach two entrances on the ground floor of the building. They come up to emergency control center to know the current situation and estimated fire floor and fire origin. After that, they go to the floor below the fire floor by fire-fighter’s elevator.

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On the other hand, Hook-and-ladder truck can directly approach to the fire room if the fire room is under 12F (See Figure6.2.).

Table 6.2. Timetable of Firefighting Scenarios from Notification to Arrival at Fire Site Hook-and-Ladder Fire Engines Trucks 1 Occupants identify fire 1 min *1 2 Occupants call fire station 2 min *2 3 Fire brigades recognize fire 4 min *2 accident 4 Fire brigades depart fire station 5 min *2 5 Fire brigades arrive at fire site 9 min 11 min *2 6 Firefighters connect fire engine 11 min 13 min *2 hose to fire stand pipe 7 Firefighters extend ladder to *3 outdoor balcony on floor of the 14 min fire origin (when fire origin is below 12F) 8 Firefighters arrive at the *2 emergency control center on 14 min ground floor to make an effective firefighting plan 9 *3 Firefighters arrive the outdoor balcony and start watering (when 17 min fire origin is below 12F) 10

Firefighters arrive at the *2 vestibules on one floor above the 17 min fire origin (29F when fire origin is 30F). 11 Firefighters arrive at the vestibules *2 on the floor of fire origin via 18 min stairwells and extinguish with water hoses. *1 Evacuation start time *2 “The required time of mobilization of fire brigade from emergency call (in Japanese)”, Tokyo Fire Department, 2009.9 1) *3 Interview to Tokyo Fire Department

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Firefighting EV

Emergency Control Center

Figure6.1. Approach route on ground floor

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30F

Deep balcony and setback prevent vertical fire spread. Fire-fighters access balcony through adjacent residential compartment. 20F 19F

Corridor-balcony path

16F

39m

Watering from balcony. Fire-fighters can access balcony through corridor-balcony path.

13F 12F 10F

Watering from ladder and balcony. Fire-fighters can access balcony through corridor-balcony path.

7F

4F Watering from ground is also reach to around 45F 2) 1F

Figure6.2. Watering operation from outside of the building

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(4)Suppression Corridors are basically assumed to be protected from smoke by initial suppression by sprinkler, fire door of the fire room. However, if those facilities failed, fire-fighters exhaust smoke in the corridor by secondary pressurization of the vestibule and elevator lobby (See Fig. 6-3 and Fig. 64). This pressurization secure the safety of their staging area – fire-fighter’s lobby. When firefighters reach at the front of the fire room, fire fighters slightly open the fire door to observe the interior condition through the gap between the door and wall in order to judge if the room can be entered safely. If they cannot enter the fire room, they spray water to the fire room to decrease the temperature and exhaust the smoke (In the condition that fire-fighters cannot enter the fire room because of the high temperature, windows will have been broken). In this situation, secondary pressurization will promote to supply fresh air to the fire room. This may function as both disadvantageous and advantageous aspect. Disadvantageous aspect is to promote fire burning by supplying fresh air. Advantageous aspect is to promote smoke exhaust from the fire room through the broken window. (5)Prevention from the fire spread by blowout fire Vertical fire spread is prevented by the balcony in this building. However, when fire-fighters start spray water and open the fire door connected to pressurized corridor, blowout fire and fire spark will spread strengthen by the pressurized air. Therefore it is very important to shower watering of the outside (See Fig. 6-3 and Fig. 6-4). In lower floors, outside watering can be conducted at lower floors relatively easily from the ground (1F to around 4F) or from the ladder of the hook-and-ladder truck (to around 12F) (See Fig. 6-2). On the other hand, watering from outside of the building is difficult. Therefore we prepare the corridor-balcony paths to easily reach to balcony from corridor without passing through residence as shown in Fig. 6-4. In emergency, fire fighters will break keys of the entrance of the residence, even though, it takes much time. The corridor-balcony paths can shorten the access time of fire fighters to balcony. Basically this corridor-balcony paths are installed for the air-and-smoke leakage path for pressurization system, therefore, this path can work for dual purpose of pressurization and fire spread prevention.

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Firefighting EV

Pushing out the smoke by inducing the pressurization air of staircase

Staircase pressurization

Shower watering from precaution gun Figure 6.3. Fire suppression and smoke exhaustion operation (Section)

Staircase pressurization

Pushing out the smoke by inducing the pressurization air of staircase

Shower watering from precaution gun Figure. 6.4. Fire suppression and smoke exhaustion operation (Plan) 81


6.4 Conclusion A fire is basically restricted the fire compartment by each residence and as fire-fighters can arrive at fire room and start watering within 20 min as above. And safe staging area for fire-fighters are prepared such as pressurized fire-fighter’s EV lobbies and outside balconies. Therefore firefighters can control the fire enough earlier than 45 min of fire resistance time of CLTs even if sprinklers fail. And fire-fighters can shower watering to prevent in early stage of fire and it can prevent fire spread to above floor of this building and adjacent buildings. Reference 1) Tokyo Fire Department: The required time of mobilization of fire brigade from emergency call, 2009.9 (in Japanese) 2) Ikaros publishing: Guidebook for fire-fighting strategy, 2015.4 (in Japanese)

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CHAPTER 7 FIRE SAFETY MANAGEMENT FOR THE TRANSIENT USERS 7.1 Characteristics of the transient users The words that explains transient users in the specification document are as follows. ・Its target market is members of the ‘gig’ economy (flexible and transient) ・Due to current and future market projections the building will maximize transient use, using platforms like AirbBNB. We suppose characteristics of such users considering above descriptions. ・Do not stay in this building for long. ・The time they stay in this building is not the same as usual workers, and changeable day by day. ・They don’t join the community of the residents in this building. ・They are not familiar with the layout plan of this building. ・They do not know well about the facilities of this building and cannot use them including fire extinguishing facilities. ・Some might not know the layout of the evacuation stirs.

7.2 Fire safety management for the transient users The important points that we took into our consideration for the fire safety of transient users having above characteristics are as follows. ・Elevators and stirs for evacuation are easy to be found out by simple layout plan with circular corridor. ・Corridor cannot be easily contaminated with smoke by smoke control system. ・Residents can evacuate by elevators for usual use. ・Even if the corridor is contaminated with smoke and some people were left in the residential unit, they can stay safe on the balcony open to outside.

Figure7.1.Plan upper floors and lower floors

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CHAPTER 8 CONCLUSION AND FUTUTR DISCUSSION  In this case study, we didn’t follow the regal requirement of Japan, because Building Standard Low of Japan does not allow the high rise wooden building.  We designed this building utilizing a wooden material for slabs, columns, and beams, and concrete for core and upper part of slabs, and steel is used for beams.  We designed this building with two different type of floor plans, one for upper floors and the other for lower floors.  Upper floors have an open air void in center surrounded by open corridors. We verified smoke behavior in this open void and confirmed the safety of the occupants.  Lower floors do not have an open void and corridor to each residential unit is an inner space. So we install pressurizing smoke control system to staircases and elevator shafts to suppress the smoke invasion from unit of fire origin to the corridor.  Our design proposal is designed totally as 45 minutes fire resistance.  45 minutes is decided in consideration of evacuation and firefighting time.  We evaluated that all the residents of this building can evacuate within 45 minute in both cases all the evacuees uses only staircases or only elevators. It was found that evacuation time does not depend on the ratio of the evacuees who use elevator.  We evaluate the time from firebreak to the moment when fire brigade start spray water in this building, and it was less than 45minutes.  Fire safety of the transient users of this residential building is secured by the simple layout plan, corridors without contamination with smoke and easy evacuation utilizing elevators. Japanese fire regulation (Building Standard Act) requires that following buildings should be selfsubsistent after fire resistance time without considering the effect of sprinklers and fire-fighters activity. A) Large scale buildings B) Specific usage such as, many and unspecified users, sleeping usage, people having difficulty in self-evacuation, and multi-usage buildings C) Buildings located in urban area This building correspond to above all items (as respect to B, this building is basically residential building, but consider that the usage of gig visitors, this building will also be regarded as accommodation facility). And this case-study’s approach is dependent on sprinklers and firefighters activity. Therefore this case-study’s approach cannot be realized in Japan as it stands. However, item A and B are basically considered the difficulty of evacuation or rescue of occupants. In this sense, our case-study covers those difficulty such as evacuation gig people, and vulnerable persons and wheelchair users employing Occupant Evacuation Elevator system. On the other and item C and also A are considered the fire spread to adjacent buildings. Japan is often called as “Earthquake country”, in fact, we have to consider fires in large earthquake situation. In this situation, sprinklers may fail and fire-fighters may not be able to come because many fire may occur in many buildings. If this large scale building collapse, adjacent buildings will also collapsed by this building and a lot of fire spark will be scattered, those will trigger urban fire. We assumed that this building is located in Tokyo. Fires in usual cases are managed and total fire safety of occupants, building structure and urban safety is satisfied by building performance and fire-fighting performance of Tokyo Fire Department. However we still have further considerations and challenges with CTL high rise buildings to cover earthquake fires.

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Appendix Appendix1; Smoke Insulation Condition and Setup of Air Supply Flow Condition 1) on Initial Fire As above，the heat release rate on initial fire given the activation of sprinkler system is 2MW. At that time, the flow rate of fire plume is expressed in the following formula. 𝑚𝑚𝑝𝑝 = 0.08𝑄𝑄1/3 𝑧𝑧 5/3 If smoke layer is kept up the top of opening, it is “z＝h”. Therefore, when Q=2,000kW，z=2.1m 𝑚𝑚𝑝𝑝 = 0.08 × 2,0001/3 × 2.15/3 = 3.53𝑘𝑘𝑘𝑘/𝑠𝑠 Then，the temperature of smoke layer Tf is expressed in the following formula, if the surface area Aw is part tangent to smoke layer. 𝑄𝑄 𝑇𝑇𝑓𝑓 = 𝑇𝑇𝑎𝑎 + 𝐶𝐶𝑝𝑝 𝑚𝑚𝑝𝑝 + ℎ𝐴𝐴𝑤𝑤 Cp is constant pressure specific heat [kJ/kgK]，h is convection heat transfer rate [kW/m2K]. Since the temperature becomes higher as the area of the residence becomes smaller, it is calculated with the smallest residence, Aw=143m2. Therefore, 𝑄𝑄 2,000 𝑇𝑇𝑓𝑓 = 𝑇𝑇𝑎𝑎 + = 20 + = 397℃ 𝐶𝐶𝑝𝑝 𝑚𝑚𝑝𝑝 + ℎ𝐴𝐴𝑤𝑤 1.101 × 3.53 + 0.01 × 143 2) on Peak Fire The corridor temperature is important as smoke control system, however, burning of a fire room on peak fire is controlled opening factor. The corridor temperature is expressed in the following simple formula1). ∆𝑇𝑇𝑅𝑅 = 3.0𝐾𝐾𝑅𝑅 2/3 𝐹𝐹𝑂𝑂𝑂𝑂 1/3 𝜏𝜏 1/6 𝑇𝑇𝑎𝑎 ∆𝑇𝑇𝐶𝐶 = 1.35𝐹𝐹𝑂𝑂𝑂𝑂 1/3 𝐾𝐾𝑅𝑅 4/9 𝐹𝐹𝑂𝑂𝑂𝑂 2/9 𝜏𝜏 5/18 𝑇𝑇𝑎𝑎 Here, Ta is atmosphere temperature, four parameters of KR, FOR, FOC, τ are expressed in the following formula. 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 𝐾𝐾𝑅𝑅 = 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 + 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 + 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 𝐹𝐹𝑂𝑂𝑂𝑂 = 𝐴𝐴𝑅𝑅𝑅𝑅 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 + 𝐴𝐴𝐶𝐶𝐶𝐶 ℎ𝐶𝐶𝐶𝐶 1/2 𝐹𝐹𝑂𝑂𝑂𝑂 = 𝐴𝐴𝐶𝐶𝐶𝐶 𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑 ≈ 0.3𝑡𝑡𝑑𝑑𝑑𝑑𝑑𝑑 𝜏𝜏 = 𝑘𝑘𝑘𝑘𝑘𝑘 Here，AROhRO1/2: Opening factor between fire room and outdoor [m5/2]，ARChRC1/2: Opening factor between corridor and fire room [m5/2]，ACOhCO1/2: Opening factor between corridor and outdoor [m5/2]，ARW: Surface area of interior wall in fire room [m2]，ACW: Surface area of interior wall in corridor [m2]，tdev: Safety target time on peak fire [sec]. The opening condition is as described below in Table 3-2. 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 = 5.0 × 2.01/2 + 4.0 × 1.01/2 = 11.071𝑚𝑚5/2 𝐴𝐴𝑅𝑅𝑅𝑅 ℎ𝑅𝑅𝑅𝑅 1/2 = 0.35 × 1.89 × 2.11/2 = 0.959𝑚𝑚5/2 𝐴𝐴𝐶𝐶𝐶𝐶 ℎ𝐶𝐶𝐶𝐶 1/2 = 0.8 × 0.51/2 = 0.566𝑚𝑚5/2 𝐴𝐴𝑅𝑅𝑅𝑅 = (12.5 + 10.0) × 2 × 2.5 + 125 = 237.5𝑚𝑚2 𝐴𝐴𝐶𝐶𝐶𝐶 = (60.0 + 2.0) × 2 × 2.5 + 120 = 430.0𝑚𝑚2 KR=0.921, FOR=0.107, FOC＝0.005, τ＝360（tdev＝1200sec） 𝑇𝑇𝑅𝑅 = 20 + 3.0 × 0.9212/3 × 0.1071/3 × 3601/6 × 293 = 1,074℃ 𝑇𝑇𝐶𝐶 = 20 + 1.35 × 0.0051/3 × 0.9214/9 × 0.1072/9 × 3605/18 × 293 = 224℃

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3) Average Pressure Difference When there is a temperature difference between the two rooms, smoke insulation effects as Figure1.1, if the pressure difference of top opening becomes zero. Although, the pressure difference differs in the height direction of opening, the concept of mean pressure difference is used so that the opening flow rate becomes equal. 4 ∆𝑃𝑃𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 = �𝜌𝜌0 − 𝜌𝜌𝑓𝑓 �𝑔𝑔ℎ 9

Figure1.1 Average Pressure Difference

4) Rooms and Openings The analysis modeling is made up fire floor and vertical spaces such as staircases, elevator shafts. The room conditions shows in Table 1.1., the openings conditions in Table 1.2.. Table1.1. Room Conditions

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Table 1.2. Opening Conditions Opening Area

Space

Wide[m]

Height[m]

Num.

Opening Flow Coefficient 2

Initial Fire

Corridor − Fire Room

(CR)

0.9 ×

2.1 ×

Vestibule 1 − Corridor

(L1C)

0.9 ×

2.1 ×

Area[m ] 1.89 m2 [L] 1.0 ＝ 1.89 m2 [O] 1.0 ＝

0.4 ×

0.5 ×

1.0 ＝

1.8 ×

2.1 ×

1.0 ＝

0.4 ×

0.5 ×

1.0 ＝

0.9 ×

2.1 ×

1.0 ＝

EV Hole − Corridor Vestibule 2 − EV Hole

(HC) (LH)

0.4 ×

0.5 ×

1.0 ＝


(SL1)

0.9 ×

2.1 ×

1.0 ＝


(SL2)

0.9 ×

2.1 ×

1.0 ＝


(EH1)

1.1 ×

2.1 ×

2.0 ＝


(EH2)

1.1 ×

2.1 ×

2.0 ＝

Fire Lift Shaft − Vestibule 1

(EL1)

1.1 ×

2.1 ×

1.0 ＝

Fire Room − Outdoor

(RO)

2.5 ×

2.0 ×

1.0 ＝

4.0 ×

1.0 ×

1.0 ＝

0.3 ×

0.3 ×

1.0 ＝

0.7 ×

2.1 ×

1.0 ＝

0.7 ×

2.1 ×

1.0 ＝

Staircase 1 − Outdoor

(SO1)

(Refuge Floor; Level 1) Staircase 2 − Outdoor

0.7 ×

2.1 ×

1.0 ＝

(Refuge Floor; Level 1)

0.7 ×

2.1 ×

1.0 ＝

Corridor − Outdoor

0.8 ×

0.5 ×

2.0 ＝

(SO2)

Corridor − Other Residence

0.9 ×

2.1 ×

7.0 ＝

Other Room − Outdoor

2.5 ×

2.0 ×

7.0 ＝

4.0 ×

1.0 ×

7.0 ＝

Corridor − Residence on Other Floors

0.9 ×

2.1 ×

8.0 ＝

Residence − Outdoor on Other Floors

2.5 ×

2.0 ×

8.0 ＝

4.0 ×

1.0 ×

8.0 ＝

Peak Fire

0.0700 [H]

0.3500

0.7000 [C]

0.0100

0.20 m2 [C] 3.78 m2 [O]

0.0000 [O]

0.7000

0.7000 [C]

0.0100

0.20 m2 [C] 1.89 m2 [O]

0.0000 [O]

0.7000

0.7000 [C]

0.0100

2

0.20 m [C] 1.89 m2 [O]

0.0000 [O]

0.7000

0.7000 [H]

0.3500

1.89 m2 [O] 4.62 m2 [C]

0.7000 [H]

0.3500

0.0100 [C]

0.0100

4.62 m2 [C] 2.31 m2 [C]

0.0100 [C]

0.0100

0.0200 [C]

0.0200

5.00 m2 [H] 4.00 m2

0.3500 [O]

0.7000

0.09 m2 [O] 1.47 m2 [O]

0.7000 0.7000 [O]

0.7000

1.47 m2 1.47 m2 [O]

0.7000 [O]

0.7000

1.47 m2 0.80 m2 [O]

0.7000 [O]

0.7000

2

13.23 m [C] 35.00 m2 [C]

0.0100 [C]

0.0100

0.0010 [C]

0.0010

28.00 m2 15.12 m2 [C]

0.0100 [C]

0.0100

40.00 m2 [C] 32.00 m2

0.0010 [C]

0.0010

7.68 m2 [O] Corridor − Outdoor on Refuge Floor 1.6 × 2.4 × 2.0 ＝ * Flow Coefficient : [O] Open, [C] Close, [H] Half Open, [L] A Little Open; 10 cm Wide

0.7000 [O]

0.7000

5) Basic Relationship between Pressure and Flow Rate The flow situation by smoke control shows in Fig. 3-2. The Pressure in each spaces is P [Pa], pressure difference is ∆P [Pa], Opening flow rate is m [kg/s], and direction of flow shows by an arrow.

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Figure1.1.Flow Balance on Fire Floor The relationship between Pressure in each spaces and flow rate based on mass conservation were prepared as bellow. [Pressure] 𝑃𝑃𝐶𝐶 = 𝑃𝑃𝑅𝑅 + ∆𝑃𝑃𝐶𝐶𝐶𝐶 𝑃𝑃𝐿𝐿1 = 𝑃𝑃𝐶𝐶 + ∆𝑃𝑃𝐿𝐿1𝐶𝐶 𝑃𝑃𝐻𝐻 = 𝑃𝑃𝐶𝐶 + ∆𝑃𝑃𝐻𝐻𝐻𝐻 𝑃𝑃𝐿𝐿2 = 𝑃𝑃𝐻𝐻 + ∆𝑃𝑃𝐿𝐿2𝐻𝐻 𝑃𝑃𝑆𝑆1 = 𝑃𝑃𝐿𝐿1 + ∆𝑃𝑃𝑆𝑆𝑆𝑆1 𝑃𝑃𝐸𝐸𝐸𝐸 = 𝑃𝑃𝐿𝐿1 + ∆𝑃𝑃𝐸𝐸𝐸𝐸𝐸𝐸1 𝑃𝑃𝐸𝐸1 = 𝑃𝑃𝐻𝐻 + ∆𝑃𝑃𝐸𝐸1𝐻𝐻 𝑃𝑃𝐸𝐸2 = 𝑃𝑃𝐻𝐻 + ∆𝑃𝑃𝐸𝐸2𝐻𝐻 𝑃𝑃𝑆𝑆2 = 𝑃𝑃𝐿𝐿2 + ∆𝑃𝑃𝑆𝑆𝑆𝑆2 [Flow Rate] 𝑚𝑚𝐶𝐶𝐶𝐶 = 𝑚𝑚𝑅𝑅𝑅𝑅 (Mass Conservation of Fire Room) 𝑚𝑚𝐿𝐿1𝐶𝐶 = 𝑚𝑚𝑆𝑆𝑆𝑆1 + 𝑚𝑚𝐸𝐸𝐸𝐸𝐸𝐸1 (Mass Conservation of Vestibule 1) 𝑚𝑚𝐻𝐻𝐻𝐻 = 𝑚𝑚𝐿𝐿2𝐻𝐻 + 𝑚𝑚𝐸𝐸1𝐻𝐻 + 𝑚𝑚𝐸𝐸2𝐻𝐻 (Mass Conservation of Elevator Hole) 𝑚𝑚𝐿𝐿2𝐻𝐻 = 𝑚𝑚𝑆𝑆𝑆𝑆2 (Mass Conservation of Vestibule 2) 𝑊𝑊𝑆𝑆1 = 𝑚𝑚𝑆𝑆𝑆𝑆1 + 𝑚𝑚𝑆𝑆1𝑂𝑂 (Mass Conservation of Stair 1) 𝑊𝑊𝑆𝑆2 = 𝑚𝑚𝑆𝑆𝑆𝑆2 + 𝑚𝑚𝑆𝑆2𝑂𝑂 (Mass Conservation of Stair 2) 𝑊𝑊𝐸𝐸𝐸𝐸 = 𝑚𝑚𝐸𝐸𝐸𝐸𝐸𝐸1 + 𝑚𝑚𝐸𝐸𝐸𝐸𝐸𝐸 (Mass Conservation of Fire Lift Shaft) 𝑊𝑊𝐸𝐸1 = 𝑚𝑚𝐸𝐸1𝐻𝐻 + 𝑚𝑚𝐸𝐸1𝑂𝑂 (Mass Conservation of Elevator 1 Shaft) 𝑊𝑊𝐸𝐸2 = 𝑚𝑚𝐸𝐸2𝐻𝐻 + 𝑚𝑚𝐸𝐸2𝑂𝑂 (Mass Conservation of Elevator 2 Shaft) [Average Pressure Difference and Open Flow Rate] 𝑚𝑚𝑖𝑖𝑖𝑖 = 𝛼𝛼𝑖𝑖𝑖𝑖 𝐴𝐴𝑖𝑖𝑖𝑖 �2𝜌𝜌𝑖𝑖 ∆𝑃𝑃𝑖𝑖𝑖𝑖

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Volume of pressurizing air is acquired as follows. Table 1.3. Setting Air Supply Flow Rate

References 1) Masafumi Sato, Takeyoshi Tanaka, Takao Wakamatsu: Simple Formulas for Predicting Fire Temperatures in the Room of Origin and the Connected Corridor, Journal of Structural Engineering, No.489, pp.137-145, Nov., 1996

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Appendix 2; Calculation of activation time of heat detector in a residential unit The activation time of a heat detector is calculated by using the equation shown in chapter 2.2(equation(2-3)-(2-5)). The calculation conditions of the heat detector are shown below. Table2.1. Calculation conditions of the activation time of the heat detector Items Value Detecting temperature of thermal point of heat detector [degC] 70 Horizontal distance from fire source to heat detector [m] 5 1/2 1/2 Response-time index of heat detector [m sec ] 15 Ceiling height [m] 2.65


The result of the activation time of the heat detector is shown below. The activation time is 50sec, and the heat release rate is 1251kW at that time. 300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0


30

60

90

120

150

180 Time［sec］


Figure2.1.

Activation time of the heat detector

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