Performance-based fire engineering of structures

390 Pages·2013·12.175 MB·xxiii, 369 p. : ill. ; 24 cm\390

by  Y C Wang, et al

WANG
FIRE ENGINEERING / STRUCTURAL ENGINEERING
BURGESS
WALD
GILLIE
Major events—notably the Broadgate fire in London, New York’s World
Trade Center collapse, and the Windsor Tower fire in Madrid—as well as P
the enlightening studies at the Cardington fire research project have given e
r
international prominence to performance-based structural fire engineering. f
o
As a result, structural fire engineering has increasingly attracted the interest
r
m
not only of fire and structural engineers but also of researchers and students.
And studies in recent years have generated a vast number of findings. a
n
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Performance-Based Fire Engineering of Structures summarizes the c
latest knowledge on performance-based approaches to structural fire e
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engineering, enabling readers to critically assess research in the field. B
Whereas most recent books have been mainly concerned with dissemination a
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of principles encapsulated in established codes of practice such as the e
Eurocodes, this work addresses in depth: d

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• Global structural behaviour and modelling ir
e
• Progressive collapse of structures in fire and the importance

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of connection robustness
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• The integrity of compartmentation in fire g
• Structural fire engineering under realistic fire conditions and i
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its implications for material properties e
• The limitations of research results and design methods e
r
• The unexploited potential for advanced fire engineering design i
n
g
This authoritative book draws on the work of internationally active o
researchers who were core members of the European Network project’s f

S
COST C26 working group on fire resistance. It helps readers develop a
t
thorough understanding of how to use advanced fire engineering design r
u
to improve structural safety and reduce construction costs. c YONG WANG, IAN BURGESS,
t
u FRANTISEK WALD AND MARTIN GILLIE
r
e
s
Y104437
ISBN: 978-0-415-55733-7
90000
9 780415 557337
Y104437_Cover_mech.indd 1 5/4/12 9:32 AM
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YONG WANG, IAN BURGESS,
FRANTISEK WALD AND MARTIN GILLIE
A SPON PRESS BOOK
CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742
© 2013 by Yong Wang, Ian Burgess, Frantisek Wald, and Martin Gillie
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
Version Date: 20120509
International Standard Book Number-13: 978-0-203-86871-3 (eBook - PDF)
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Contents
Preface xv
Notations xix
1 Introduction to fire safety engineering and the role of
structural fire engineering 1
1.1 Introduction to fire engineering 1
1.2 Roles of structural fire resistance 3
1.3 The process of performance-based
fire engineering of structures 6
1.4 Introduction to the book 7
2 Recent major structural fire events and their implications 13
2.1 Introduction 13
2.2 Broadgate fire, London, 1990 14
2.2.1 The fire and observations 14
2.2.2 Implications 14
2.3 Cardington fire research programme, 1994–2003 15
2.3.1 Fire tests 15
2.3.2 Main results from the tests on
the steel-framed structure 17
2.3.3 Implications 19
2.3.3.1 Reduction of fire protection 20
2.3.3.2 Fire-induced structural collapse 21
2.4 World Trade Center collapses, 11 September 2001 23
2.4.1 World Trade Center Buildings 1 and 2 23
2.4.2 World Trade Center Building 7 25
2.5 Windsor Tower fire, Madrid, 12 February 2005 27
2.6 Summary and context of this book 29
v
vi  Contents
3 Introduction to enclosure fire dynamics 31
3.1 Introduction 31
3.2 Standard fires 31
3.3 Fires in small compartments 32
3.3.1 Heat release rate 33
3.3.2 Gas temperatures: Pettersson’s method 34
3.3.3 Gas temperatures: Eurocode parametric curves 35
3.3.4 Decay 41
3.4 Fires in large compartments and travelling fires 42
3.4.1 Horizontally travelling fires 42
3.4.1.1 Clifton’s model 44
3.4.1.2 Rein’s model 47
3.4.2 Vertically travelling fires 51
3.5 Computer models of compartment fires 51
4 Heat transfer 53
4.1 Introduction 53
4.2 Basics of heat transfer 54
4.2.1 Fourier’s law of heat conduction 54
4.2.2 One-dimensional steady-state heat
conduction in a composite element 55
4.2.3 Thermal boundary conditions 57
4.2.4 Transient heat transfer 58
4.3 Convective heat transfer coefficients 58
4.3.1 Types of flow 59
4.3.2 Dimensionless numbers 59
4.3.3 Approximate values of convective heat
transfer coefficients for fire safety 61
4.4 Radiant heat transfer coefficient 62
4.4.1 Total power of black-body thermal radiation 62
4.4.2 Intensity of directional thermal radiation 63
4.4.3 Exchange of thermal radiation
between black-body surfaces 63
4.4.4 Configuration (view) factor Φ 64
4.4.5 Exchange area 66
4.4.6 Radiant heat transfer of grey-body surfaces 66
4.4.7 Network method for radiant heat
transfer between grey-body surfaces 66
Contents  vii
4.5 Some simplified solutions for heat transfer 70
4.5.1 Temperatures of unprotected steelwork in fire 71
4.5.2 Temperatures of protected steelwork in fire 72
4.5.3 Section factors 74
4.6 Importance of using appropriate
thermal properties of materials 75
4.7 Effects of thermal boundary conditions 77
4.8 Brief introduction to numerical analysis of heat transfer 78
4.9 Concluding remarks 80
5 Material properties 81
5.1 Introduction 81
5.2 Structural materials 82
5.2.1 Relevant thermal properties 82
5.2.1.1 Emissivity 82
5.2.1.2 Thermal conductivity 83
5.2.1.3 Specific heat capacity 87
5.2.1.4 Thermal expansion 91
5.2.2 Mechanical properties 95
5.2.2.1 Rate dependency of
mechanical properties 95
5.2.2.2 Transient and isothermal
materials testing methods 97
5.2.2.3 Eurocode EN 1993-1-2 stress-strain
curves for structural carbon steels 99
5.2.2.4 Reduction factors for other
carbon steel components 102
5.2.2.5 An alternative form of stress-strain
curve for numerical analysis: the
Ramberg-Osgood equation 106
5.2.2.6 Biaxial properties 108
5.2.2.7 High-temperature mechanical
properties of concrete 109
5.2.2.8 EN 1992/EN 1994-1-2 stress-strain
curves for concrete in compression 110
5.2.2.9 Tensile strength for
advanced modelling 114
5.2.2.10 Biaxial failure surfaces for concrete 115
5.2.2.11 Load-induced transient
strain of concrete 119
viii  Contents
5.3 Fire protection materials 131
5.3.1 General 131
5.3.2 Theoretical considerations 132
5.3.2.1 Density 132
5.3.2.2 Specific heat 133
5.3.2.3 Thermal conductivity 133
5.3.3 Thermal properties of common
fire protection materials 135
5.3.3.1 Rock fibre 136
5.3.3.2 Mineral wool 137
5.3.3.3 Calcium silicate 137
5.3.3.4 Vermiculite 140
5.3.3.5 Gypsum 142
5.3.3.6 Intumescent coating 146
5.4 Concluding remarks 153
6 Element structural fire resistance design 155
6.1 Design principles 155
6.1.1 Basis of element design 155
6.1.2 Structural Eurocodes 155
6.1.3 Design procedures 157
6.1.4 Thermal loading 157
6.1.5 Mechanical loading 157
6.2 Concrete structures 159
6.2.1 Basis of design 159
6.2.2 Simplified methods 159
6.2.2.1 500°C isotherm method 159
6.2.2.2 Zone method 160
6.2.3 Spalling 162
6.3 Steel structures 163
6.3.1 Basis of design 163
6.3.2 Simple analytical models 163
6.3.2.1 Cross-section classification 163
6.3.2.2 Members in tension 163
6.3.2.3 Members in buckling 164
6.3.2.4 Members in bending 165
6.3.2.5 Lateral torsional buckling 166
Contents  ix
6.3.2.6 Class 4 cross sections 166
6.3.2.7 Connection design 167
6.3.3 Critical temperature 167
6.4 Composite steel and concrete structures 168
6.4.1 Composite slabs and beams 168
6.4.1.1 Critical temperature method 168
6.4.1.2 Bending moment resistance model 169
6.4.2 Composite columns 169
6.5 Timber structures 170
6.5.1 Basis of design 170
6.5.2 Charring depth 170
6.5.3 Simple analytical models 171
6.5.3.1 Reduced cross-section method 171
6.5.3.2 Reduced properties method 172
6.5.4 Connections 173
6.5.4.1 Simplified rules 173
6.5.4.2 Reduced load method 174
6.6 Masonry structures 174
6.6.1 Basis of design 174
6.6.1.1 Isotherm method 175
6.7 Aluminium structures 177
6.7.1 Basis of design 177
6.7.2 Simple design models 177
6.8 Fire resistance design worked examples 177
6.8.1 Concrete beam by 500°C isotherm method 177
6.8.1.1 Normal temperature design:
ultimate limit state 178
6.8.1.2 Design for fire situation 179
6.8.1.3 Verification of fire resistance 180
6.8.2 Concrete wall by zone method 183
6.8.3 Unprotected steel beam 184
6.8.3.1 Normal temperature design 185
6.8.3.2 Design for fire situation 186
6.8.4 Fire-protected steel column 187
6.8.4.1 Normal temperature design 189
6.8.4.2 Design for fire situation 190
6.8.4.3 Verification in the strength domain 191