5 Manual to Eurocode: / TRADA Manual SECOND EDITION
Manual for the design of timber building structures to Eurocode 5
The Institution of Structural Engineers and BM TRADA
Manual for the design of timber building structures to Eurocode 5 (2nd edition)
Revising author (second edition: 2019–)
K Ranasinghe BSc(Hons) PhD (University of Wales, Trinity Saint David)
Reviewers
G Evans BSc(Hons) PhD CEng FICE FIStructE MBCS (Constructex)
R J L Harris BSc CEng FICE FIStructE FIMMM (Time for Timber Ltd)
D Trujillo MSc CEng MIStructE (University of Coventry)
Publishing
L Baldwin BA(Hons) Dip Pub (The Institution of Structural Engineers)
J Shanahan BA(Hons) MA (BM TRADA)
Acknowledgements
The Institution of Structural Engineers acknowledges the input and support of TRADA and its service provider BM TRADA in the development of this Manual.
Permission to reproduce extracts from British Standards is granted by BSI. British Standards can be obtained in PDF or hard copy formats from the BSI online shop: www.bsigroup.com/Shop or by contacting BSI Customer Services for hardcopies only:
Tel: +44 (0)20 8996 9001, Email: cservices@bsigroup.com.
Figure 10.10: © BRE, reproduced with permission from Multi-storey timber frame buildings: a design guide (BR 454).
Front cover image: The Macallan Distillery, Moray, Scotland. Project by Rogers Stirk Harbour+Partners. Photo © Joas Souza
Published by The Institution of Structural Engineers and BM TRADA International HQ, 47–58 Bastwick Street, London EC1V 3PS, United Kingdom
T:+44(0)20 7235 4535
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First published (version 1.0) December 2019
ISBN 978-1-906335-36-6 (print)
ISBN 978-1-906335-37-3 (pdf)
© 2019 The Institution of Structural Engineers and Warringtonfire Testing and Certification Ltd
The Institution of Structural Engineers, TRADA, the author and reviewers who produced this Manual have endeavoured to ensure the accuracy of its contents. However, the guidance and recommendations given should always be reviewed by those using the Manual in light of the facts of their particular case and any specialist advice. No liability for negligence or otherwise in relation to this Manual and its contents is accepted by the Institution, TRADA, their servants or agents. Any person using this Manual should pay particular attention to the provisions of this Condition. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means without prior permission of The Institution of Structural Engineers, who may be contacted at 47–58 Bastwick Street, London EC1V 3PS, United Kingdom.
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The Institution of Structural Engineers and BM TRADA | iii Manual for the design of timber building structures to Eurocode 5 (2nd edition) Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) Uncorrected proofs Foreword xvi Tables xvii Figures xxi Glossary xxiii Notation xxxi 1. Introduction 1 1.1 Aims 1 1.2 Eurocode system 1 1.2.1 Basis for Eurocode design 2 1.3 Contents 2 1.4 Scope 3 1.4.1 Structures covered 3 1.4.2 Principal subjects covered 3 1.4.3 Subjects not covered 3 1.5 Definitions 3 1.5.1 Technical terms 3 1.5.2 Axis nomenclature 3 1.6 Sources of additional information 4 2. General principles 5 2.1 Basis of design 5 2.1.1 Basic requirements 5 2.1.2 Design codes 5 2.1.3 Structural materials compliance 5 2.2 Responsibility for design 6 2.3 Building use and location 6 2.4 Design life 6 2.5 Design situations 7 2.6 Stability 7 2.7 Construction 7 2.8 Movement 7 2.8.1 Moisture movement 8 2.8.2 Thermal movement 8 2.8.3 Differential movement 8 2.8.4 Movement joints 8 2.9 Creep 9 2.10 Robustness and disproportionate collapse 9 Contents
iv | The Institution of Structural Engineers and BM TRADA Manual for the design of timber building structures to Eurocode 5 (2nd edition) Uncorrected proofs Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) 2.10.1 Robust construction 9 2.10.2 Accidental actions 9 2.11 Fire resistance 9 2.12 Acoustic, thermal and air-tightness requirements 10 2.13 Durability 10 2.14 Maintenance 10 2.15 Service class 10 2.15.1 Effect of moisture on strength and stiffness 10 2.15.2 Definitions of service classes 11 2.16 Load duration 11 2.16.1 Effect of load duration on strength and stiffness 11 2.16.2 Definitions of load duration classes 11 2.17 Factors to allow for effects of moisture and load duration 11 2.17.1 Strength modification factor, kmod 11 2.17.2 Deformation modification factor, kdef 12 2.17.3 Large sections of solid timber 12 3. Design principles 15 3.1 Actions 15 3.1.1 Types of action 15 3.1.2 Characteristic values of actions 15 3.1.3 Design values of actions 16 3.1.4 Action combinations 16 3.2 Limit states 17 3.2.1 Ultimate limit states (ULS) 17 3.2.2 Serviceability limit states (SLS) 19 3.2.3 Creep effects in assemblies 21 3.2.4 Use of frame analysis programs 22 3.2.5 Floor vibration 24 3.3 Timber materials 24 3.3.1 Structural timber materials 24 3.3.2 Dimensions and tolerances 24 3.3.3 Characteristic values 30 3.3.4 Design values of strength properties 30 3.3.5 Design values of stiffness properties 41 3.4 Protective treatments 42 3.4.1 Decay 42 3.4.2 Insect attack 43 3.4.3 Preservative treatment 43 3.4.4 Surface finishes 44 3.4.5 Corrosion of metal parts 44 3.4.6 Spread of flame 44 3.5 Material specifications 46
The Institution of Structural Engineers and BM TRADA | v Manual for the design of timber building structures to Eurocode 5 (2nd edition) Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) Uncorrected proofs 3.5.1 Overview 46 3.5.2 Dimensions 47 3.5.3 Materials 47 3.5.4 Protective treatments 50 3.5.5 Marking 50 4 Initial design 39 4.1 Scope 53 4.2 Principles of initial design 53 4.2.1 General principles 53 4.2.2 Vertical load transfer 53 4.2.3 Horizontal load transfer 53 4.2.4 Load cases 54 4.2.5 Sizing 54 4.2.6 Outline of initial design process 57 4.3 Fire resistance 59 4.3.1 Introduction 59 4.3.2 Insulation method 59 4.3.3 Sacrificial timber method 59 4.4 Movement 60 4.5 Durability 60 4.6 Acoustic, thermal insulation and air-tightness requirements 60 4.6.1 General 60 4.6.2 Acoustic 60 4.6.3 Thermal insulation 60 4.7 Densities and weights 60 4.8 Roofs 60 4.8.1 Introduction 60 4.8.2 Trussed rafter roofs 63 4.8.3 Cut roofs 65 4.8.4 Other types of roof 66 4.9 Floors 66 4.9.1 Introduction 66 4.9.2 Joists and beams 66 4.9.3 Decking 67 4.10 Walls 67 4.10.1 Columns 67 4.10.2 Timber frame walls 71 4.11 Connections 73 4.11.1 Introduction 73 4.11.2 Choosing a connection method 77 4.12 Estimating 77 4.13 Completing the design 78
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Manual for the design of timber building structures to Eurocode 5 (2nd edition) Uncorrected proofs Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) 4.13.1 Introduction 78 4.13.2 Checking of all information 78 4.13.3 Amendment of drawings as a basis for final calculations 79 4.13.4 Preparation of a list of design data 79 4.13.5 Final design calculations 80 5 Detailed design rules 81 5.1 General design procedure for structural members 81 5.2 Flexural members (solid rectangular sections) 81 5.2.1 Straight beams 81 5.2.2 Tapered, curved and pitched cambered glulam beams (derived/adapted from Clause 6.4.3 of BS EN 1995) 86 5.3 Members subject to axial compression (solid rectangular members) 86 5.3.1 Members subject to axial compression only (derived/adapted from Clause 6.3.2 of BS EN 1995) 86 5.3.2 Members subject to axial compression and bending about the y axis only (derived/adapted from Clauses 6.2.4, 6.3.2 and 6.3.3 of BS EN 1995) 87 5.3.3 Members subject to axial compression and bending about both axes (derived/adapted from Clauses 6.2.4, 6.3.2 and 6.3.3 of BS EN 1995) 87 5.4 Members subject to axial tension 88 5.4.1 Members subject to axial tension only(derived/adapted from Clause 6.1.2 of BS EN 1995) 88 5.4.2 Members subject to axial tension and bending about the y axis only (derived/adapted from Clauses 6.1.2 and 6.2.3 of BS EN 1995) 88 5.4.3 Members subject to axial tension and bending about both axes (derived/adapted from Clauses 6.1.2 and 6.2.3 of BS EN 1995) 89 5.5 Flitch beams 89 5.5.1 Introduction 89 5.5.2 Scope 89 5.5.3 Design method 90 5.5.4 Strength checks 91 5.5.5 Stability 92 5.5.6 Bolts for UDLs 92 5.5.7 Bolts for point loads 92 5.5.8 Bolts at reactions 93 5.5.9 Distances, spacings and orientation 93 5.6 Providing structural stability 93 5.7 Bracing of compression members and of beam or truss systems 93 5.8 Horizontal diaphragms 93 5.8.1 Simple solution 93 5.8.2 BS EN 1995 method 94 5.9 Vertical diaphragms 96 5.10 Fire resistance 96 5.10.1 Introduction 97
The Institution of Structural Engineers and BM TRADA
The Institution of Structural Engineers and BM TRADA | vii Manual for the design of timber building structures to Eurocode 5 (2nd edition) Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) Uncorrected proofs 5.10.2 Protection by insulation 97 5.10.3 Calculation of reduced cross-section 97 5.10.4 Rules for the analysis of reduced cross-sections 97 5.11 Building a robust structure 99 6 Connections 103 6.1 Introduction 103 6.2 Dowel-type connections 103 6.2.1 Introduction 103 6.2.2 Specification 103 6.2.3 Lateral load capacity of a timber connection 103 6.2.4 Design values 106 6.3 Nailed connections 110 6.3.1 Introduction 110 6.3.2 Laterally loaded nails 113 6.3.3 Axially loaded nails 113 6.4 Screwed connections 118 6.4.1 Introduction 118 6.4.2 Laterally loaded screws 120 6.4.3 Axially loaded screws 120 6.5 Bolted connections 128 6.5.1 Introduction 128 6.5.2 Laterally loaded bolts 128 6.5.3 Axially loaded bolts 129 6.6 Dowelled connections 135 6.6.1 Introduction 135 6.6.2 Laterally loaded dowels 140 6.7 Glued joints 140 6.7.1 Introduction 140 6.7.2 Design 141 6.7.3 Adhesives 142 6.8 Glued rods 142 6.8.1 Introduction 142 6.8.2 Design 145 6.9 3-dimensional (3D) nailing plates 149 6.10 Punched metal plate fasteners and nailing plates 149 6.10.1 Introduction 149 6.10.2 Punched metal plate fasteners 150 6.10.3 Nailing plates 150 6.11 Timber connectors 150 6.11.1 Introduction 150 6.11.2 Design 150 6.12 Proprietary connectors 153
viii | The Institution
Structural Engineers and BM TRADA Manual for the design of timber building structures to Eurocode 5 (2nd edition) Uncorrected proofs Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) 6.13 Joint slip 153 6.13.1 Introduction 153 6.13.2 Slip modulus 153 6.13.3 Instantaneous slip 153 6.13.4 Final slip 153 6.13.5 Allowing for slip in frame analysis programs 154 6.14 Connections in fire 154 7 Roofs 157 7.1 General design requirements 157 7.1.1 Functions of a roof 157 7.1.2 Data required 157 7.1.3 Actions 160 7.1.4 Bracing 162 7.1.5 Raised tie trusses 162 7.1.6 Serviceability 162 7.2 Flat roofs 162 7.3 Trussed rafters 163 7.3.1 Introduction 163 7.3.2 Girder trusses 163 7.3.3 Design information 163 7.3.4 Stability 164 7.3.5 Notching and drilling 164 7.4 Site-built cut roofs 164 7.5 Timber trusses 166 7.6 Pyramid roofs 167 7.7 Gridshells 168 8 Floors 169 8.1 General design requirements 169 8.1.1 Functions of a floor 169 8.1.2 Actions 169 8.1.3 Design information 169 8.2 Types of timber floor 170 8.3 Materials 171 8.3.1 Specification 171 8.3.2 Beams 174 8.3.3 Joists 174 8.3.4 Strutting 174 8.3.5 Decking 174 8.3.6 Fixing 175 8.4 Floor design 176 8.4.1 General 176 8.4.2 Ultimate limit states 176
of
The Institution of Structural Engineers and BM TRADA | ix Manual for the design of timber building structures to Eurocode 5 (2nd edition) Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) Uncorrected proofs 8.4.3 Serviceability limit states 176 8.4.4 Stairwell trimming 179 8.4.5 Built-up beams 180 8.5 Fire resistance 181 8.6 Robustness 181 8.7 Acoustic and thermal requirements 181 8.7.1 Acoustic 181 8.7.2 Thermal 182 9 Low-rise open frame construction 183 9.1 Forms of open frame construction 183 9.1.1 Scope 183 9.1.2 Construction principles 183 9.1.3 Selection of frame and materials 183 9.2 Design 183 9.2.1 Principles 183 9.2.2 Imperfections 184 9.2.3 Stability and bracing 185 9.2.4 Base connections 185 9.3 Construction details 186 9.3.1 Situations to avoid 186 9.3.2 Base details 186 9.3.3 Pin-jointing techniques 187 9.3.4 Stiff-jointing techniques 187 9.4 Movement 187 10 Platform timber frame buildings 189 10.1 Introduction 189 10.2 Design procedure 189 10.3 Actions 189 10.3.1 Wind loads 189 10.3.2 Other actions 191 10.4 Material selection 191 10.4.1 Roofs 191 10.4.2 Floors 191 10.4.3 Walls 191 10.5 Overall stability calculations 197 10.5.1 General (Clause 6.4.1(1)(a) of BS EN 1990) 197 10.5.2 Overturning 198 10.5.3 Sliding 201 10.5.4 Roof uplift 201 10.5.5 Roof sliding 202 10.6 Roof design 202 10.7 Floor design 203
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Manual for the design of timber building structures to Eurocode 5 (2nd edition) Uncorrected proofs Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) 10.8 Wall design 203 10.8.1 Racking resistance of timber frame walls 203 10.8.2 Racking resistance in asymmetric buildings 203 10.8.3 Alternative methods of providing racking resistance 206 10.8.4 Masonry wall ties 206 10.8.5 Design of wall studs 207 10.8.6 Design of lintels 208 10.8.7 Horizontal deflection of shear walls 208 10.9 Foundations 208 10.10 Fire resistance 208 10.11 Movement 208 10.11.1 Introduction 208 10.11.2 Moisture movement 209 10.11.3 Movement from induced stresses 209 10.11.4 Interface settlement 209 10.11.5 Masonry expansion 209 10.11.6 Differential movement 209 10.11.7 Movement joints 210 10.12 Other requirements 210 10.12.1 Acoustic 210 10.12.2 Thermal 211 10.13 Robustness of platform timber frame 211 10.14 Platform timber frame above four storeys 211 11 Checking and specification guidance 213 11.1 General checking requirements 213 11.1.1 Local Authority checking 213 11.1.2 General checking 213 11.2 Codes and standards 214 11.3 Material specifications 214 11.4 Protection against decay, insect attack and corrosion 215 11.5 Deflection and creep 215 11.6 Trussed rafter roofs 215 11.7 Floors 215 11.8 Platform timber frame 215 11.9 Checking aids 216 12 Workmanship, installation, control and maintenance 217 12.1 General 217 12.2 Members 217 12.2.1 Condition of timber members 217 12.2.2 Moisture content 217 12.2.3 Dimensions 217 12.2.4 Modifications 220
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The Institution of Structural Engineers and BM TRADA | xi Manual for the design of timber building structures to Eurocode 5 (2nd edition) Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.) Uncorrected proofs 12.2.5 Treatment of cut services 220 12.3 Connections 221 12.3.1 General 221 12.3.2 Nailed connections 221 12.3.3 Screwed connections 221 12.3.4 Bolted connections 221 12.3.5 Dowelled connections 222 12.3.6 Connections made with timber connectors 222 12.3.7 Adhesively bonded joints 222 12.4 Trussed rafters 222 12.5 Storage and handling 222 12.5.1 Protection of materials and components 222 12.5.2 Handling 223 12.6 Assembly, erection and installation 223 12.6.1 General 223 12.6.2 Trussed rafters 223 12.6.3 Floors 226 12.7 Treatments 226 12.7.1 Preservative and flame retardant treatments 226 12.7.2 Anti-corrosive treatments 227 12.7.3 Decorative treatments 227 12.8 Production and site control 227 12.8.1 Control plan 227 12.8.2 Inspection 227 12.9 Maintenance 227 12.9.1 Responsibility 227 12.9.2 Tightening of bolts 227 12.9.3 Ancillary components 228 12.9.4 Structural metalwork 228 12.9.5 Other matters 228 References 229
Foreword
For structural engineers in the UK who were familiar with the permissible stress approach of BS 5268 in the UK, the move to load factor design in Eurocode 5 (BS EN 1995) marked a significant change in approach to timber design. It is now almost 15 years since that first full version of Eurocode 5 was published and much has changed. The code offered a more rigorous standard as compared with its predecessor and also it enabled pan-European collaboration in research and practice. This has enabled timber’s full potential to be released, and the extent and scale of timber engineering in the UK and throughout Europe has expanded enormously.
It is, therefore, now timely for the publication of a fully revised second edition of the Manual. Whereas the first edition drew on the services of a task group convened by the IStructE, for the second edition Keerthi Ranasinghe alone has taken on the daunting task of reviewing the first edition for the necessary updates needed to comply with changes in BS EN 1995. He has gone about this methodically and rigorously, consulting with practising engineers as he has worked at the task. We owe a debt of gratitude to Keerthi for undertaking this work and, in commending this revised Manual to the construction industry, I also offer him our thanks.
Richard Harris BSc CEng FIStructE FICE FIMMMA note from the revising author
‘It was vital that we updated the manual considering all the amendments that were implemented in not just Eurocode 5, but all the supporting standards as well since 2004. By far the leading resource for timber engineering, the new edition ensures that it will continue to be the must-have reference for engineers and specifiers who are keen to work to Eurocode 5’.
Keerthi Ranasinghe
BSC(Hons) PhDxii |
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Manual for the design of timber building structures to Eurocode 5 (2nd
Sample Section:
3 Design principles
3.1 Actions
3.1.1 Types of action
BS EN 199014 distinguishes between permanent actions (dead weight of structure, finishes, permanent fixtures and fixed partitions) and variable actions (every other type of action). Actions involving exceptional conditions of the structure or its exposure (including fire, explosion, impact or local failure) are also defined but dealt with separately under ‘accidental design situations’.
3.1.2 Characteristic values of actions
For permanent actions it is usually acceptable to use an average weight as the characteristic value or, if a range of weights is specified, the highest value in the range. For variable actions, an upper characteristic value appropriate to the design life (e.g. once in 50 years) is normally used. However, in ULS load cases where actions can have a favourable effect (e.g. tile weight resisting overturning), the lowest value should be used for permanent loads if a range of weights is specified. Other adjustments for favourable effects are made by means of the partial load factors (Table 3.1).
The values to be used in calculations are:
• characteristic dead load16
• characteristic imposed load16
• characteristic snow load32
• characteristic wind load33
Note
a Values for unfavourable effects are for main values. Values for favourable effects are for actions which relieve some of the load on a member or tend to stabilise a member or structure. For the design of elements in a foundation, e.g. timber piles, see Clause A1.3.1(5) of BS EN 1990, approach 1
b The combined check is an optional alternative to separate calculations for equilibrium and strength verifications when both have to be carried out. However, if it is employed then it must also be verified that setting γG to 1.00 for both the favourable and unfavourable parts of the permanent load does not produce a less favourable effect.
Derived/adapted from Tables NA.A1.2(A) and NA.A1.2(B) of NA to BS EN 1990
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Permanent actions, γG Variable actions, γQ Unfavourable Favourable Unfavourable Favourable Strength checks 1.35 1.00 1.50 0.00 Equilibrium checks 1.10 0.90 1.50 0.00 Combined equilibrium and strength checksb 1.35 1.15 1.50 0.00
Table 3.1: Partial load factors for ULSa
3.1.3 Design values of actions
For fundamental ULS the characteristic values of actions are converted to design values by the partial load factors shown in Table 3.1. Additional factors applicable to snow and wind loads are given in the relevant codes. For accidental design situations the load factors for permanent and variable actions are set at 1.0. For SLS the load factor is 1.0, unless the load is favourable (e.g. an imposed load on the second span of a two-span joist) in which case a value of 0.0 should be used.
3.1.4 Action combinations
Where more than one variable action acts simultaneously, a leading variable action is chosen, and the others are reduced by specified combination factors. In cases where the leading variable action is not obvious, each action should be checked in turn to determine the combination which produces the worst effect. Other factors are used to determine the design value of accidental load combinations, and the average value of variable loads in the calculation of creep deformation. All these factors, normally referred to as ‘psi’ factors, are shown in Table 3.2. For examples of their use, see Section 3.2.
a The roof imposed load need not be applied at the same time as wind/snow loads, particularly for Category H roofs (Clause 3.3.2(1) of BS EN 1991-1-1).
from Table A1.1 of NA to BS EN 1990
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Action Factors for the representative value of an action ψ0 ψ1 ψ2 Permanent actions – weights of materials and permanent fixtures N/A N/A N/A Imposed loads in buildings – category from BS EN 1991-1-1 A: domestic and residential areas 0.7 0.5 0.3 B: office areas 0.7 0.5 0.3 C: congregation areas 0.7 0.7 0.6 D: shopping areas 0.7 0.7 0.6 E: storage areas (including lofts) 1.0 0.9 0.8 H: roofsa 0.7 0.0 0.0 Snow loads on buildings – see BS EN 1991-1-3 Sites up to 1000m above sea level 0.5 0.2 0.0 Wind loads on buildings – see BS EN 1991-1-4 0.5 0.2 0.0 Note
Table 3.2: Factors for representative values of variable actions (for buildings covered by this Manual)
Derived/adapted
Clause 3.3.1 of BS EN 1991-1-1 states that when imposed loads act simultaneously with other variable actions (e.g. wind or snow) the total imposed loads on the floors of multi-storey buildings shall be considered as one variable action. For timber structures this requirement is applicable principally to the instantaneous load case (wind + snow + floor imposed) and to the short-term load case (snow + floor imposed). In addition, Clause 6.3.1.2 states than for building ‘‘categories A to D, for columns and walls, the total imposed loads from several storeys may be multiplied by a reduction factor α n .’’ α n is applicable to buildings with four or more storeys, and its values should be taken from the National Annex to BS EN 1991-1-1. For timber, the medium-term load case (floor imposed) may be critical, and since this does not involve other variable actions the design value of the individual imposed loads from two or more floors may be calculated as Qk,1 + Σi>1ψ0, Qk,i. This value may be reduced by α n if and where it is applicable.
3.2 Limit states
This Manual adopts the limit state principle and the partial factor format common to all Eurocodes and defined in BS EN 1990.
3.2.1 Ultimate limit states (ULS)
3.2.1.1 Definitions
ULS are breached by loss of equilibrium or material failure. All relevant states should be checked.
• equilibrium:
• uplift of whole or part (e.g. roof) of structure
• overturning
• sliding
The stability of the foundations should be checked in accordance with BS EN 1997-134.
• strength:
• material rupture in bending, tension, compression or shear
• stability failure (e.g. buckling of columns, lateral torsional buckling of beams, stresses induced by sway in portals, diagonal bracing in roofs or walls)
• connection failure — yield in fasteners or metal-work, or timber failure by embedment, shear, splitting, fastener pull-out or head pull-through
Where time-dependent deformations (deflections of members or slip in connections) cause a significant redistribution of effects in an assembly or framework, the strength of the members should be considered both before and after creep deformation has occurred.
Fundamental design situations occur during the construction phase and in normal use. Accidental design situations occur at or following an exceptional event such as fire, exceptional snowdrift, impact or explosion. All relevant design situations should be considered.
3.2.1.2 Load cases
The load timber can resist depends on the duration of the load. Therefore, a duration should be assigned to every action (Table 2.2). When several actions occur simultaneously, a separate load case should be considered for each load duration represented, unless it is obvious that it will not govern the design. The duration of each load case should be taken as the shortest load duration of any load in the load case.
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Manual for the design of timber building structures to Eurocode 5 (2nd
design of timber building structures to Eurocode
Manual for the design of timber building structures to Eurocode
Preview pages | Manual for the design of timber building structures to Eurocode 5 (2nd ed.)
5
This edition includes changes to sections on material properties, bearing capacities, connections, glulam, racking, and fire, along with the insertion of new sections referencing CLT and the new product standard.
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