ISO TR 24679-2-2017 Fire safety engineering - Performance of structure in fire - Part 2 Example of an airport terminal.pdf

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1、 ISO 2017 Fire safety engineering Performance of structure in fire Part 2: Example of an airport terminal Ingnierie de la scurit incendie Performance des structures en situation dincendie Partie 2: Exemple dun terminal daroport TECHNICAL REPORT ISO/TR 24679-2 Reference number ISO/TR 24679-2:2017(E)

2、First edition 2017-07 ISO/TR 24679-2:2017(E)ii ISO 2017 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or

3、mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Gene

4、va, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO/TR 24679-2:2017(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Terms, definitions and symbols 1 4 Design strategy for fire safety of structures . 3 5 Quantification of the performance of

5、structures in fire 3 5.1 Step 1: Scope of the project for fire safety of structures . 3 5.1.1 Built environment characteristics 3 5.1.2 Fuel loads . 4 5.1.3 Mechanical actions . 5 5.2 Step 2: Identify objectives, functional requirements and performance criteria for fire safety of structures 6 5.3 St

6、ep 3: Trial design plan for fire safety of structures . 7 5.4 Step 4: Design fire scenarios and design fires 9 5.4.1 Design fire scenarios .10 5.4.2 Design fires (thermal actions) .11 5.5 Step 5: Thermal response of the structure 17 5.5.1 Smoke temperature from FDS simulation 17 5.5.2 Calculating st

7、eel temperature exposed to smoke .19 5.6 Step 6: Mechanical response of the structure .20 5.6.1 Deformation analysis of the structure 21 5.6.2 Strength analysis of the main span under fire exposure 22 5.7 Step 7: Assessment against the fire safety objectives .26 5.8 Step 8: Documentation of the desi

8、gn for fire safety of structures .27 5.9 Factors and influences to be considered in the quantification process 28 5.9.1 Material properties .28 5.9.2 Effect of continuity and restraint (interaction between elements and materials) .30 5.9.3 Use of test results .30 5.9.4 Fire spread routes 30 6 Guidan

9、ce on use of engineering methods .31 Annex A (informative) Views and plans of the airport terminal 32 Bibliography .34 ISO 2017 All rights reserved iii Contents Page ISO/TR 24679-2:2017(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standar

10、ds bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organi

11、zations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its f

12、urther maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ di

13、rectives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in

14、the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of

15、 ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: w w w . i s o .org/ iso/ foreword .html. This document was prepared by Te

16、chnical Committee ISO/TC 92, Fire safety, Subcommittee SC 4, Fire safety engineering. A list of all parts in the ISO 24679 series can be found on the ISO website.iv ISO 2017 All rights reserved ISO/TR 24679-2:2017(E) Introduction This document is an example of the application of ISO 24679-1. It pres

17、erves the numbering of subclauses in ISO 24679-1 and so omits numbered subclauses for which there is no text or information for this example. Therefore, the following two points should be kept in mind. a) This document is not intended to provide uniform technical provisions for the user, but rather

18、demonstrate how ISO 24679-1 is applied in compliance with the related standards of China. b) Fire service intervention has been considered when defining the maximum heat release rate of the design fire in this case because the fire brigade is dedicated and is approximately 1 km away from the airport

19、 terminal. It is completely legal in China to consider the fire service intervention, which may not be the case in other countries. Therefore, when taking any reference from this document, attention should be paid to the requirements of the related national standards. It should be noted that this ex

20、ample does not follow every step described in ISO 24679-1, but rather follows its principles as applicable to the building regulatory in China. ISO 2017 All rights reserved v Fire safety engineering Performance of structure in fire Part 2: Example of an airport terminal 1 Scope This document provide

21、s a fire engineering application relative to fire resistance assessment of an airport terminal structure according to the methodology given in ISO 24679-1. It follows step by step the procedure given by ISO 24679-1. Some requirements relative to Chinese building regulation are taken into account con

22、cerning the fire scenarios. The fire safety engineering applied to an airport terminal takes into account the real fire data based in fire tests. It is important to note that the intervention of fire service brigade dedicated to this airport, located approximately 1 km away, has been taken into acco

23、unt in definition of fire scenarios. For the fire modelling, both fire extinguishing system and the smoke extraction are not considered but the fire fighter intervention has been taken into account 10 min after the starting of fire. 2 Normative references There are no normative references in this do

24、cument. 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 24679-1 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ w

25、ww .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp 3.2 Symbols S m design value of combination of action effect S Gk nominal value of permanent load effect S Tk temperature effect of fire on structure S Qk nominal value of floor or roof live load effect S

26、 Wk nominal value of wind load effect f frequency coefficient of floor or roof live load q quasi-permanent coefficient of floor or roof live load TECHNICAL REPORT ISO/TR 24679-2:2017(E) ISO 2017 All rights reserved 1 ISO/TR 24679-2:2017(E) 0 partial safety factor associated with the uncertainty of t

27、he action and/or action effect model, 1.15 for Class A building and 1.05 for other buildings Q heat release rate of the fire source (kW) fire growth rate (kW/s 2 ) t time t 0 smouldering time (s) t j alarm time (min) t c time for fire brigade to respond and start leaving the fire station, (min) t l

28、travel time (min) t z prepare for firefighting (min) t time step (s) usually not larger than 5 s T s , T g internal temperature of the steel under fire condition and air temperature (K) s density of the steel (kg/m 3 ) c s specific heat of the steel J/(kgK) F exposed surface area per unit length (m

29、2 /m) V volume per unit length (m 3 /m) c+r combined heat transfer coefficient W/(m 3 K) c convective heat transfer coefficient between air and the surface of the element, c= 25 W/(m 2 K) r radiant heat transfer coefficient between air and the surface of the element W/(m 2 K) r combined radiant emis

30、sivity, r= 0,5 Stefan-Boltzmann constant, = 5,67 10 8( W/(m 2 K 4 ) T s temperature of the steel (C) s coefficient of thermal expansion (K 1 ) s heat conductivity W/(mK) c s specific heat J/(kgK) s density (kg/m 3 ) f yT yield strength of the steel at elevated temperature (N/mm 2 ) f y yield strengt

31、h of the steel at room temperature (N/mm 2 ) T reduction factor of the yield strength of steel at elevated temperature E T modulus of elasticity of steel at elevated temperature (N/mm 2 ) E modulus of elasticity of steel at room temperature (N/mm 2 ), taken from GB 500172 ISO 2017 All rights reserve

32、d ISO/TR 24679-2:2017(E) T reduction factor of the modulus of elasticity of steel at elevated temperature f yT effective yield strength under temperature f pT proportional limit under temperature E T lope of the linear elastic range under temperature pT strain at the proportional limit under tempera

33、ture yT yield strain under temperature tT limiting strain for yield strength under temperature 4 Design strategy for fire safety of structures The built environment is an airport terminal that has been provided with automatic fire alarm system, sprinkler system, fire hydrant and smoke control system

34、, etc. Furthermore, the fire service brigade dedicated is located approximately 1 km away from the airport terminal. Consequently, their intervention has been taken into account in definition of fire scenarios. The heat release rates (HRR) of combustible products, which could be found at the differe

35、nt locations of the terminal, have been defined by fire tests. An advanced model has been used to define the thermal action in different volumes of the studied terminal. The thermomechanical behaviour of the principal structure of the terminal, based on advanced and simplified methods, is carried ou

36、t in function of the real thermal actions defined previously. This case study is intended to illustrate the steps given in ISO 24679-1. Therefore, the following design process has been adopted. 5 Quantification of the performance of structures in fire 5.1 Step 1: Scope of the project for fire safety

37、 of structures This is the initial step in a fire safety design process for a new or an existing built environment. Below are the main items included in this step. 5.1.1 Built environment characteristics This airport terminal (see Figure 1) is 80 m deep, 252 m long and 22,13 m high. It has two stori

38、es above the ground and one underground, with a total floor area as about 7,1 10 4m 2 . More details are given in Annex A. The airport terminal has been provided with automatic fire alarm system, sprinkler system, fire hydrant and smoke control system, etc. ISO 2017 All rights reserved 3 ISO/TR 2467

39、9-2:2017(E) Figure 1 View of the terminal building See Table 1 for the main functions on different floors. Table 1 Main functions at different floors of the terminal Floor Floor level Main function First floor 1,45 m0,00 m Domestic departure hall, domestic baggage sorting hall, international baggage

40、 sorting hall, international baggage claim hall, baggage claim hall for transfer, international arrival, entry formalities hall, shopping area and so on. Second floor 7, 25 m Hall for sending off, international check in, international departure, shopping area and offices. The column, beam, floor str

41、uctures on first floor are reinforced concrete. The column and roof structures on the second floor are steel. In case of fire, the flame and hot smoke may endanger the integrity and stability of steel structures on the second floor. Therefore, the purpose of this case study is to calculate the mecha

42、nical performances of the steel elements in the event of fire so as to determine if the trial plan is feasible. 5.1.2 Fuel loads Fuel load analysis Fuel load is the essential factor to analyse the full developed fire. Therefore, combustibles inside the terminal, including their amount, properties an

43、d location should be understood thoroughly before analysing the fire scenario. In this case study, fuel loads is classified as a) dead load, b) live load, and c) temporary load. The fuel loads of this airport terminal have been defined based on the survey and investigation done by University of Scie

44、nce and Technology of China (see Reference 7). See Table 2 for the detail.4 ISO 2017 All rights reserved ISO/TR 24679-2:2017(E) Table 2 Fuel load density No. Location Fuel load density MJ/m 2 1 Shopping area 470,0 2 Offices 439,0 3 Departure hall 93,0 4 Baggage sorting area National 104,0 Internatio

45、nal 93,0 Baggage warehouse 670,0 5 Security check area 81,0 6 Frontier inspection and the customs 31,0 7 Check-in hall 64,0 5.1.3 Mechanical actions Fire action on structures is an accidental action. The probability of the occurrence of fire is quite low. Therefore, when considering the combined loa

46、d, only the combination of one accidental (fire load in this case study) load with other loads, such as permanent load, floor or roof live load or wind load, is considered. CECS 200 requires that the combination of action effects in case of fire shall be calculated according to Formula (1) and Formu

47、la (2): 0(1) (2) whereS m is the design value of combination of action effect;S Gk is the nominal value of permanent load effect;S Tk is the temperature effect of fire on structure;S Qk is the nominal value of floor or roof live load effect;S Wk is the nominal value of wind load effect; f is the fre

48、quent coefficient of floor or roof live load (given in GB 50009); q is the quasi-permanent coefficient of floor or roof live load (given in GB 50009); 0 is the partial factor associated with the uncertainty of the action and/or action effect model, 1.15 for Class A building and 1.05 for other buildi

49、ngs. Temperature effect of fire on structure S Tkis the inner force and deformation caused by elevated temperature, which is equivalent to rod end effect. The roof of the terminal is arch-shaped. The rise-to-span ratios of the roof arches are quite small ( f/l 0,1) as shown in Figure 2. Therefore, the shape coefficient of the wind load is negative according to GB 50009. The actio