Structural design –achieving excellence

Task groupA M Cormie BSc CEng FIStructE FICE FIES MWeldI (J&D Pierce (Contracts) Ltd)J S Johnston BSc(Hons) CEng FIStructE FICE FConsE (Sinclair Johnston & Partners)A M Low MA CEng MICE (Arup)M W Manning FREng MA(Cantab) CEng MIStructE (Arup) ChairmanJ C Mason MA CEng MIStructE (Alan Baxter & Associates)Dr C Melbourne BEng PhD CEng FIStructE FICE (University of Salford)R D Nicholl BEng(Hons) CEng FIStructE MICE (AECOM)M F Ryland BSc(Hons) CEng FIStructE MICE (Ryland Consulting)F E Weare MSc DIC CEng FIStructE MICE MIMMM DMS MIHT (Consultant)

Corresponding memberDr F T K Au BSc(Eng) MSc(Eng) PhD CEng FIStructE MICE (University of Hong Kong)

Reviewing editorsA M Cormie BSc CEng FIStructE FICE FIES MWeldI (J&D Pierce (Contracts) Ltd)A S Rahman MEng ACGI (The Institution of Structural Engineers)

AcknowledgementsFigure 1.1: Andy GardnerFigure 1.2: Colin BrenchleyFigure 2.1: J&D Pierce (Contracts) LtdFigure 3.1: J&D Pierce (Contracts) LtdFigure 4.1: Royal Commission on the Ancient and Historical Monuments of WalesFigure 4.2: Fairfax New Zealand LimitedBox 4.1: Antony DubberBox 5.1: Angus CormieFigure 5.2: J&D Pierce (Contracts) LtdFigure 5.3: J&D Pierce (Contracts) LtdFigure 5.7: Milner AssociatesBox 5.2: Courtesy of the National Law Enforcement Museum, Washington, DCBox 5.4 (dampers under deck): Victor Salcedo, GERB Vibration Control Systems Inc.Box 5.4 (plan with deck removed): ArupFigure 5.9: Angus CormieFigure 5.10: Joseph Penzien, Godden Collection, NISEE-PEER, University of California, BerkeleyFigure 6.1: Mott MacDonaldFigure 7.1: J&D Pierce (Contracts) LtdBox 8.1: J&D Pierce (Contracts) Ltd

Published by:The Institution of Structural Engineers,47–58 Bastwick Street, London EC1V 3PS, United KingdomTelephone: þ44(0)20 7235 4535 Fax: þ44(0)20 7235 4294Email: mail@istructe.org, Website: www.istructe.org

First published 2015Version 1.0 (May 2015)ISBN 978-1-906335-29-8

# 2015 The Institution of Structural Engineers

The Institution of Structural Engineers and those individuals who contributed to this Report haveendeavored to ensure the accuracy of its contents. However, the guidance and recommendationsgiven in the Report should always be reviewed by those using the Report in the light of the facts oftheir particular case and specialist advice obtained as necessary. No liability for negligence orotherwise in relation to this Report and its contents is accepted by the Institution, the members ofthe task group, their servants or agents. Any person using this Report should pay particularattention to the provisions of this Condition.

No part of this publication may be reproduced, stored in a retrieval system or transmitted in anyform or by any means without prior permission of The Institution of Structural Engineers, who maybe contacted at 47–58 Bastwick Street, London EC1V 3PS.

Contents

Foreword iv

1 Introduction 11.1 Introduction and scope 11.2 References 2

2 The structural engineer’s responsibilities 32.1 General considerations 32.2 Ethics 32.3 Professional development 42.4 Role of the structural engineer 42.5 Managing risk 42.6 References 62.7 Bibliography 6

3 Engaging in design 73.1 Concept design 73.2 Scheme design 7

3.2.1 Overview 73.2.2 Non-structural evaluations 83.2.3 Structural evaluations 93.2.4 Output 10

3.3 Detailed design 103.4 References 103.5 Bibiliography 10

4 Structural design philosophies 114.1 Overview of structural performance 114.2 Value 114.3 Design life 124.4 Limit states 124.5 Actions 13

4.5.1 General 134.5.2 Permanent actions 134.5.3 Variable actions 134.5.4 Accidental or extreme actions 144.5.5 Sensitivity analysis 15

4.6 Sustainability 154.7 References 164.8 Bibliography 17

5 Stability, robustness and serviceability 185.1 Scope 185.2 Stability 185.3 Stability systems and features 18

5.3.1 General features 185.3.2 Examples found in different forms of

construction 215.4 Stability during construction 235.5 Stability during alteration 235.6 Robustness 245.7 Dynamics 255.8 Serviceability 26

5.8.1 General 265.8.2 Movement effects 27

5.9 References 285.10 Bibliography 28

6 Demonstrating structural adequacy 296.1 Overview 296.2 Analysis 29

6.2.1 General 296.2.2 Superstructure 296.2.3 Substructure 306.2.4 Reliability and risk 306.2.5 Assessment of existing structures 31

6.3 Calculations 316.4 Computer modelling 316.5 Testing and monitoring 326.6 Codes of practice 326.7 Checks 336.8 References 33

7 Communicating the design 357.1 Communication needs 35

7.1.1 Why, what and when to communicate 357.1.2 Needs of the client 357.1.3 Needs of the design team 357.1.4 Needs of the drafting/detailing team 367.1.5 Needs of the construction team 367.1.6 Building control and statutory authorities 36

7.2 Effective strategies for communicating information 367.3 Information for construction 37

7.3.1 Working drawings 377.3.2 Specifications 377.3.3 Schedules 377.3.4 Bill of quantities 38

7.4 Design coordination and change control 387.5 References 387.6 Bibliography 38

8 The construction stage 398.1 Role of the structural engineer 398.2 Contract relationships 398.3 Temporary works 408.4 Quality control of workmanship 408.5 Site inspections and reports 408.6 References 418.7 Bibliography 41

The Institution of Structural Engineers Structural design – achieving excellence iii

Foreword

This report has arisen from the Institution’s decisionto update the following reports:– Aims of structural design 2nd edition (1987)– Communication of structural design (1975)– Stability of buildings (1988)– The achievement of structural adequacy (1990)

An Institution Task group, ‘The Philosophy ofStructural Design’, was convened to carry out thiswork. This is the second of the two reports the groupdecided to produce to amalgamate the original four.Its accompanying publication is Structural Design –the engineer’s role which was published in 2011.

The original reports were of their era and with thepassage of time the processes and tools available tostructural engineers have moved forward.

This report is primarily aimed at structural engineersin their formative years post-graduation strivingtowards chartered membership of the Institution. Itcovers the different stages that engineers willdiscover as they progress through the design andconstruction of a project, from inception and schemedesign, through detailed design to construction.

There have been many changes in structural designsince the original reports were published. Some aresignificant such as code changes and majoradvances in computing power. However, theprinciples of loadpath and basic building physics areunchanged through time.

The conceptual output from this report is anunderstanding of the plan of engagement of thestructural engineer with clients and other designprofessionals through the design process. Oncethrough the plan the engineer should be able toadvise on and develop the structural conceptsthrough the varying stages, such that a competent,safe and sustainable end product is achieved – withexcellence.

Sincere thanks are due to the time and effortsexpended by the group in their many and variedcontributions to this report. Special mention must goto Arif Rahman, former Technical Assistant at theInstitution, for his collation and tireless editing of thedrafts and close attention to detail during the formalreview period.

Angus CormieReviewing Editor

iv The Institution of Structural Engineers Structural design – achieving excellence