e C PD7974-3:2019 101 BSl StandardsPublication Committee member copy: Do n Application offiresafetyengineering principles to the design of buildings Part 3: Structural response to fire and fire spread beyond the enclosure of origin (Sub-system 3) bsi.
PD 7974-3:2019 PUBLISHED DOCUMENT Committee member copy: Do not reproduce Publishing and copyright information The BSI copyright notice displayed in this document indicates when the document was last issued. @ The British Standards Institution 2019 Published by BSI Standards Limited 2019 ISBN 978 0 580 97727 5 ICS 13.220.20; 91.040.01 The following BSI references relate to the work on this document: Committee reference FSH/24 Draft for ment 18/30373550 DC Amendments/corrigenda issued since publication Date Text affected @ THE BRITISH STANDARDS INSTITUTION 2019 ALL RIGHTS RESERVED
PUBLISHED DOCUMENT PD 7974-3:2019 e c Contents Page d Foreword iv 1Scope 1 0 Normative references 1 3 Terms and definitions 1 p 4 Symbols 4 5 Design approach to PD 7974-3 7 e 5.1 General 7 5.2 Interaction with BS 7974 framework 7 Figure 1 - Interaction between the various professions and the design team in addressing t PD 7974-3 foctors 7 5.3 Functional objectives 7 n 5.4 Identification of fire hazards and possible consequences 8 5.5 Identification of acceptance criteria and appropriate methods of analysis 8 0 5.6 Establishing trial fire safety designs 9 5.7 Establish fire scenarios for analysis 9 D 5.8 Analysis 10 Figure 2 Procedure for onalysis within PD 7974-3 10 opy: 6 Analysis methods 11 6.1 General 11 6.2 Basis of analysis 11 6.3 Accuracy 12 6.4 Means 12 6.5 Measures 13 a 7 Evaluation of fire conditions 13 7.1 Design fire characterization 13 r 7.2 Selection of design fires 13 e Figure 3 - Gas temperature in non-bustible and bustible partments [8] 15 8 Evaluation of thermal response 15 8.1 Thermal response of elements within enclosure 15 m 8.2 Empirical data 15 8.3 Simplistic calculations 16 e 8.4 Advanced calculations 17 8.5 Quantitative analysis of heat flow by conduction 17 E 8.6 Quantitative analysis of heat flow by convection 19 8.7 Quantitative analysis of heat flow by radiation 19 8.8 Characterizing the condition of fires spreading from openings in enclosures 20 e 9 Behaviour of separating elements in fire 21 e 9.1 Behaviour of fire-resisting separating elements 21 9.2 Maintaining the separating capability of elements or constructions 33 Figure 4 Typical detail showing protection to a floor beam with αa service penetration t 35 9.3 Behaviour of non-fire-resisting separating elements 36 opn aq uo up afra ym f aunpuaa o pad po I a unproven elements subject to fire exposure 36 10 Analysis of structural response of loadbearing structural elements and frames 10.1 Concepts 37 0 Table 2 - Partial safety factors for loads (PD 6688-1-2:2007 Table 1) 38 10.2 Acceptance criteria 39 10.3 Methods for determining structural response 40 THE BRITISH STANDARDS INSTITUTION 2019 - ALL RIGHTS RESERVED 1
PD 7974-3:2019 PUBLISHED DOCUMENT e c Figure 5 - Maximum steel temperature concept Toble 3Values ofk 42 42 Figure 6 - General approach to structural fire sofety design 45 d AnnexA( (informative) Fire spread mechanisms 49 0 Figure A.1 - Routes for fire transmission 51 r Annex B (informative) Design fires p Annex C (informative) Heat transfer (and thermal response) of specific materials 54 e Table C.1 Guidance on the material surface emissivity of construction materials 54 r Figure C.1 - Configuration factors for typical scenarios 55 Figure C.2 - Calculation of section factors 60 Tabie C.2 - Caiculation of element factors (EF) 61 Figure C.3 - Calculation of element factors 62 m Table C.3 Typical set of coating thicknesses for α profile non-reactive spray-applied protection system 9 Figure C.4 Typical set of board thicknesses for a box encasement fire protection system 64 0 Figure C.5 - Compartment parameters 67 D Table C.4 - Location of columns between windows to avoid direct flame impingement 67 Figure C.6 - Spandrel beam with shielded fanges 68 Tabie C.5 - Spondrel beams 68 L" Figure C.7 Calculation methods for determining the temperature profiles though masonry elements 71 Figure C8 Temperature gradient through autoclaved concrete masonry with a density of 0 400 kg/m2 to 800 kg/m? 72 c Annex D (informative) Temperature-dependent properties of non-loadbearing construction systems - Thermal properties of materials used in posite sandwich panels Tabile D.1 - Comparison of expansion of materiais used in posite sondwich ponels r e Table D.2 Comparison of specific heat capacity of materials used in posite sandwich ponels 78 Table D.3 - Thermal conductivity for various densities of mineral (rock) wool at elevated b temperatures 78 m Figure D.1 Thermal conductivity for various densities of mineral (rock) wool at elevated temperatures 6 Table D.4 - Constonts for caiculating the thermal conductivity of mineral wool at elevated e temperatures 6 m Tabie D.5 - Thermal conductivity of cellular glass Table D.6 - Thermal conductivity of expanded polystyrene 80 Tabie D.7 - Thermal conductivity of extruded polystyrene 80 e Table D.8 - Thermal conductivity of phenolic foom 80 Table D.9 - Thermal conductivity of polyisocyanate foam 80 e Table D.10 - Thermal conductivity of rigid polyurethane foam 80 Table D.11 - Thermal conductivity through the cell gas for various blowring gases 81 t Table D.12 - Typicol densities of core materials used in soncdwich panels 81 n Annex E (informative) Structural response of specific materials 82 m Figure E.1 - Design methods for fire limit state (FLS) design adopted in BS EN 1992-1-2 83 m Figure E.2 - Principle design methodologies adopted in BS EN 1993-1-2 85 Figure E.3 - Schematic representation of the pressive and tensile forces of α floor zone during fire 90 0 Figure E.4 llustration of the defection of α multi-zone posite floorsystem with protected and unprotected members 91 II THE BRITISH STANDARDS INSTITUTION 2019 - ALL RIGHTS RESERVED
PUBLISHED DOCUMENT PD 7974-3:2019 member copy: Do not reproduce Figure E.5 - Ilustration of cotenary action developed in α multi-zone posite floor system 92 Table E.1 Notional char depths for various species after 30 min and 60 min in the standard furnace test (BS 476-20) 95 Table E.2 - Values of k_ for different ponents/elements 96 Figure E.6A - Definition of residual cross-section and effective cross-section 97 Figure E.6B - Relationship between k and time of fire exposure for unprotected surfaces and for protected surfaces where t ≤ 20 min 86 Figure E.6C - Relationship between k and time of fire exposure for protected surfoces where >20min 86 Table E.3- Determination of k 86 Figure E.7 - Equotions (E.17) to (E.19) illustrated 99 Annex F (informative) Fire resistant load bearing structural solutions 105 Annex G (informative) Methodology for establishing the extended application of fire resistance test results 107 Bibliography 114 e Summary of pages This document prises a front cover and inside front cover pages ito vi pages 1 to 118 an inside back cover and a back cover. THE BRITISH STANDARDS INSTITUTION 2019 ALL RIGHTS RESERVED II1
英文原版 PD 7974-3 2019 消防安全工程原理在建筑设计中的应用 第3部分 火灾和火势蔓延至火源范围结构以外的结构响应.pdf
