1、BSI Standards Publication PD ISO/TR 24679-3:2015 Fire safety engineering Performance of structure in fire Part 3: Example of an open car parkPD ISO/TR 24679-3:2015 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 24679-3:2015. The UK participation in it
2、s preparation was entrusted to Technical Committee FSH/24, Fire safety engineering. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for it
3、s correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 83146 1 ICS 13.220.01 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Pol
4、icy and Strategy Committee on 31 August 2015. Amendments issued since publication Date Text affectedPD ISO/TR 24679-3:2015 ISO 2015 Fire safety engineering Performance of structure in fire Part 3: Example of an open car park Ingnierie de la scurit incendie Performance des structures en situation din
5、cendie Partie 3: Exemple dun parking arien largement ventil TECHNICAL REPORT ISO/TR 24679-3 Reference number ISO/TR 24679-3:2015(E) First edition 2015-08-01PD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All
6、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 mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested fro
7、m 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, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgPD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E)Foreword iv I
8、ntroduction v 1 Scope . 1 2 Normative references 1 3 Terms and definitions . 2 4 Design strategy for fire safety of structures . 2 5 Quantification of the performance of structures in fire 2 5.1 Fire performance of structures Design process 2 5.2 Step 1: Scope of the project for fire safety of struc
9、tures . 2 5.2.1 Built environment characteristics 2 5.2.2 Fuel loads . 4 5.2.3 Mechanical actions . 5 5.3 Step 2: Identify objectives, functional requirements, and performance criteria for fire safety of structures 5 5.4 Step 3: Trial design plan for fire safety of structures . 6 5.5 Step 4: Design
10、fire scenarios and design fires 8 5.5.1 Design fire scenarios 8 5.5.2 Design fires (thermal actions) .10 5.6 Step 5: Thermal response of the structure 13 5.7 Step 6: Mechanical response of the structure .17 5.8 Step 7: Assessment against the fire safety objectives .22 5.9 Documentation of the design
11、 for fire safety of structures 22 5.10 Factors and influences to be considered in the quantification process 22 6 Guidance on use of engineering methods .22 Annex A (informative) Analysis of structural behaviour of open car parks .23 Annex B (informative) Views and plans of the open car park .38 Bib
12、liography .41 ISO 2015 All rights reserved iii Contents PagePD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is norm
13、ally 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 organizations, governmental and non-governmental, in liaison with ISO, also take part in t
14、he 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 further maintenance are described in the ISO/IEC Directives, Part 1. In particular th
15、e 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/directives). Attention is drawn to the possibility that some of the elements of this docu
16、ment 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 the Introduction and/or on the ISO list of patent declarations received (see www.iso.or
17、g/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 meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO
18、principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information. The committee responsible for this document is ISO/TC 92, Fire safety, SC 4, Fire safety engineering.iv ISO 2015 All rights reservedPD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E) Introductio
19、n This Technical Report is an example of the application of ISO/TS 24679, prepared in the format of ISO/TS 24679. It includes only those sections of ISO/TS 24679 that describe steps of the methodology for assessing the performance of structures. It preserves the numbering of sections in ISO/TS 24679
20、 and so omits numbered sections for which there is no text or information for this example. This example is intended to illustrate the implementation of the steps of fire resistance assessment, as defined in ISO/TS 24679. Only steps that are considered as relevant in this example are well detailed i
21、n this Technical Report. ISO 2015 All rights reserved vPD ISO/TR 24679-3:2015PD ISO/TR 24679-3:2015Fire safety engineering Performance of structure in fire Part 3: Example of an open car park 1 Scope This Technical Report provides a fire safety engineering application relative to fire resistance ass
22、essment of an open car park according to the methodology given in ISO/TS 24679. This report describes the adopted process which followed the same step by step procedure as that given within ISO/TS 24679. The Annexes of this Technical Report presents the detailed numerical analysis results obtained f
23、or most severe fire scenarios on the basis of this specific fire safety engineering procedure for open car parks. The fire safety engineering applied here to open car parks, with respect to their fire resistance, considers specific design fire scenarios as well as corresponding fire development. It
24、takes account of localized heating, global structural behaviour rather than single structural member resistance, etc. In fact, in case of fire in open car parks, only a small part of structure will be exposed directly to fire because of the limited fire spread due to open environment as well as rapi
25、d fire brigade intervention. In consequence, the load redistribution to cold parts might become possible and can be taken into account through global structural analysis. This kind of approach based on 3D modelling of the mechanical response of composite floor was already used in various fire safety
26、 engineering projects in France to check the stability of unprotected composite steel framed open car parks subject to most severe real fire scenarios. Finally, it should be mentioned that these severe fire scenarios have been selected for fire resistance purposes only. They should not be used, for
27、example, for smoke control purposes. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the ref
28、erenced document (including any amendments) applies. ISO/TS 24679:2011, Fire safety engineering Performance of structures in fire EN 1990:2002, Eurocode 0: Basis of structural design EN 1991-1-2:2002, Eurocode 1: Actions on structures Part 1-2: General actions Actions on structures exposed to fire E
29、N 1992-1-2:2004, Eurocode 2: Design of concrete structures Part 1-2: General Structural fire design EN 1994-1-1:2004, Eurocode 4: Design of composite steel and concrete structures Part 1-1: General Common rules and rules for buildings EN 1994-1-2:2005, Eurocode 4: Design of composite steel and concr
30、ete structures Part 1-2: General Structural fire design TECHNICAL REPORT ISO/TR 24679-3:2015(E) ISO 2015 All rights reserved 1PD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E) 3 Terms and definitions For the needs of this example, following terms and definitions are used in addition to those described in
31、 ISO/TS 24679:2011, Clause 3. 3.1 edge secondary beam secondary beam located at the faade part of the floor and parallel to faade 3.2 edge primary beam primary beam located at the faade part of the floor and parallel to faade 3.3 internal secondary beam secondary beam located in internal part of the
32、 floor (other secondary beams than edge secondary beams) 3.4 internal primary beam primary beam located in internal part of the floor (other primary beams than edge primary beams) 3.5 PRS profil reconstitu soud welded steel section 4 Design strategy for fire safety of structures The built environmen
33、t is an open car park. With its well-ventilated configuration and easy intervention condition of firefighters, a fully developed fire covering the whole area of the floor is not possible. In consequence, the fire spread will be limited and remains always localized according to a statistic survey of
34、real fires in open car parks. As a result, burning of several cars is considered as relevant to predict the impact on structural stability. A global structural analysis is carried out to evaluate the behaviour of non-insulated steel frame and profiled steel deck slab. This approach is based on 3D mo
35、delling of the mechanical response of composite floor which takes account of localized heating and global structural behaviour rather than single structural member resistance. 5 Quantification of the performance of structures in fire 5.1 Fire performance of structures Design process The various step
36、s of the design process considered in the conducted fire safety engineering study are detailed in the following sections. 5.2 Step 1: Scope of the project for fire safety of structures 5.2.1 Built environment characteristics The car park is a 3-storey building, of which all faades are open. Accordin
37、g to the French regulation, it is considered as an “open car park”, meaning that it meets simultaneously the following conditions: At each level, the openings shall be put at least on two opposite faades; These openings shall have a total area equal to at least 50 % of the total area of these faades
38、, of which the height has to be taken as the free height of the floor and shall not be less than 5 % of the corresponding single floor total area; The maximum distance between two opposite and opened faades shall be less than 75 m.2 ISO 2015 All rights reservedPD ISO/TR 24679-3:2015ISO/TR 24679-3:20
39、15(E) There are about 520 car park spaces (130 spaces per level). Each car park place occupies an area of 2,5 m by 5,0 m. Moreover, two access ramps allowing vehicle access to various levels are predicted at longitudinal edge part of the building (see Figure 1). Each gross floor area is 31,30 m 112,
40、65 m. The total building height is 10,274 m (height for ground storey: 4,658 m and for other stories: 2,808 m). The structure of this building is designed with the following sizes: Span of secondary beams: 15,5 m; Span of primary beam: 10,0 m; Spacing of columns: 10,0 m in direction of primary beams
41、 and 15,5 m in direction of secondary beams. As the building is located in a region subject to strong seismic action, the owner of the building decided to use steel and concrete composite structures for this building. However, the ramps remain in concrete and separated structurally from parking area
42、. In consequence, the spacing of secondary beams is about 3,33 m which is also the span of the 120 mm thick floor composite slab (with a trapezoidal 0,88 mm thick steel decking). The applied load of design on the floors is taken as follows: Live load: 2,5 kN/m 2 ; Permanent load on the floor due to
43、screed and services: 0,2 kN/m 2for intermediary floor level and 1,10 kN/m 2for roof level; Self weight of floor (slab and steel members): 2,53 kN/m 2 ; Self weight of faade: 0,8 kN/m on longitudinal edges and 2,0 kN/m on transverse edges. More details of structure are given in Annex B. ISO 2015 All
44、rights reserved 3PD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E) Figure 1 View of the built environment of investigated open car park: plan view (top) and perspective view (bottom) 5.2.2 Fuel loads In order to reach both realistic and efficient means of fire resistance safety of the structure, fuel loa
45、ds are characterized on an available scientific data basis in terms of the heat release rate of car fires and 4 ISO 2015 All rights reservedPD ISO/TR 24679-3:2015ISO/TR 24679-3:2015(E) fire propagation behaviour between cars according to real car fire tests performed at CTICM in the scope of a Europ
46、ean research project. 1The average mass, the mass of combustible materials, and the heat released of 5 categories of European cars are reported in Table 1. Table 1 Average car mass, mass of combustible materials, and heat release for different category of cars (of the 90s) Category Car mass (kg) Mas
47、s of combustible materials (kg) Heat release (MJ) 1 850 200 6 000 2 1 000 250 7 500 3 1 250 320 9 500 4 1 400 400 12 000 5 1 400 400 12 000 Fire from cars using liquefied petroleum gas is considered to be less severe on the basis of French fire tests with this type of cars. 5.2.3 Mechanical actions
48、The mechanical actions in fire situation are determined in accordance with EN 1990. In consequence, the following load combination is used: 1,0 G + 0,7 Q with: G for sum of all the permanent loads and Q for live load. The snow actions are considered as negligible because the construction zone is in
49、a tropical region. As far as design wind loads are concerned, they are much lower than the lateral seismic loads and the resisting systems (bracing system shown in Annex B of this report) to seismic actions are therefore strong enough to resist wind effects which, under fire situation, have a combination factor equal to 0,2 (instead of 1,5 at ultimate state design at room temperature). In this case, the wind effects under localized fire become also negligible with respect
