Structure and Architecture This Page Intentionally Left Blank Structure and Architecture Angus J. Macdonald Department of Architecture, University of Edinburgh Second edition Architectural Press OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEW DELHI Structure and Architecture Architectural Press An imprint of Butterworth-Heinemann Linacre House, Jordan Hill, Oxford OX2 8DP 225 Wildwood Avenue, Woburn, MA 01801-2041 A division of Reed Educational and Professional Publishing Ltd A member of the Reed Elsevier plc group First published 1994 Reprinted 1995, 1996, 1997 Second edition 2001 © Reed Educational and Professional Publishing Ltd 1994, 2001 All rights reserved. No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1P 0LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publishers British Library Cataloguing in Publication Data Macdonald, Angus J. Structure and architecture. – 2nd ed. 1. Structural design. 2. Architectural design I. Title 721 ISBN 0 7506 4793 0 Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress Printed and bound in Great Britain Composition by Scribe Design, Gillingham, Kent Contents Preface vii 6.3 Reading a building as a structural object 67 Acknowledgements ix 6.4 Conclusion 71 Introduction xi 7 Structure and architecture 73 1 The relationship of structure to building 1 7.1 Introduction 73 7.2 The types of relationship between 2 Structural requirements 9 structure and architecture 73 2.1 Introduction 9 7.3 The relationship between architects 2.2 Equilibrium 9 and engineers 114 2.3 Geometric stability 9 2.4 Strength and rigidity 15 Selected bibliography 124 2.5 Conclusion 21 Appendix 1: Simple two-dimensional force 3 Structural materials 22 systems and static equilibrium 128 3.1 Introduction 22 A1.1 Introduction 128 3.2 Masonry 22 A1.2 Force vectors and resultants 128 3.3 Timber 25 A1.3 Resolution of a force into 3.4 Steel 30 components 129 3.5 Concrete 35 A1.4 Moments of forces 129 A1.5 Static equilibrium and the equations 4 The relationship between structural form of equilibrium 129 and structural efficiency 37 A1.6 The ‘free-body-diagram’ 132 4.1 Introduction 37 A1.7 The ‘imaginary cut’ technique 132 4.2 The effect of form on internal force type 37 4.3 The concept of ‘improved’ shapes in Appendix 2: Stress and strain 134 cross-section and longitudinal A2.1 Introduction 134 profile 40 A2.2 Calculation of axial stress 135 4.4 Classification of structural elements 45 A2.3 Calculation of bending stress 135 A2.4 Strain 138 5 Complete structural arrangements 47 5.1 Introduction 47 Appendix 3: The concept of statical 5.2 Post-and-beam structures 48 determinacy 140 5.3 Semi-form-active structures 55 A3.1 Introduction 140 5.4 Form-active structures 57 A3.2 The characteristics of statically 5.5 Conclusion 59 determinate and statically indeterminate structures 140 6 The critical appraisal of structures 60 A3.3 Design considerations in relation to 6.1 Introduction 60 statical determinacy 146 6.2 Complexity and efficiency in structural design 60 Index 149 This Page Intentionally Left Blank Preface to the second edition The major theme of this book is the have had on architectural style and form. The relationship between structural design and penultimate chapter, on structural criticism, architectural design. The various aspects of has also been extensively rewritten. It is hoped this are brought together in the last chapter that the ideas explored in both of these which has been expanded in this second chapters will contribute to the better edition, partly in response to comments from understanding of the essential and readers of the first edition, partly because my undervalued contribution of structural own ideas have changed and developed, and engineering to the Western architectural partly as a consequence of discussion of the tradition and to present-day practice. issues with colleagues in architecture and structural engineering. I have also added a Angus J. Macdonald section on the types of relationship which have Department of Architecture, existed between architects, builders and University of Edinburgh engineers, and on the influence which these December 2000 vii This Page Intentionally Left Blank Acknowledgements Angus Macdonald would like to thank all in their captions. Thanks are due to all those those, too numerous to mention, who have who supplied illustrations and especially to assisted in the making of this book. Special Pat Hunt, Tony Hunt, the late Alastair Hunter, thanks are due to Stephen Gibson for his Jill Hunter and the staff of the picture libraries carefully crafted line drawings, Hilary Norman of Ove Arup & Partners, Anthony Hunt for her intelligent design, Thérèse Duriez for Associates, the British Cement Association, the picture research and the staff of Architectural Architectural Association, the British Press (and previously Butterworth-Heinemann) Architecture Library and the Courtauld for their hard work and patience in initiating, Institute. editing and producing the book, particularly Thanks are also due most particularly to Neil Warnock-Smith, Diane Chandler, Angela my wife Pat, for her continued Leopard, Siân Cryer and Sue Hamilton. encouragement and for her expert scrutiny of Illustrations other than those commissioned the typescript. specially for the book are individually credited ix This Page Intentionally Left Blank Introduction It has long been recognised that an preserve its physical integrity and survive in appreciation of the role of structure is the world as a physical object. The part of the essential to the understanding of architecture. building which satisfies the need for ‘firmness’ It was Vitruvius, writing at the time of the is the structure. Structure is fundamental: founding of the Roman Empire, who identified without structure there is no building and the three basic components of architecture as therefore no ‘commodity’. Without well- firmitas, utilitas and venustas and Sir Henry designed structure there can be no ‘delight’. Wooton, in the seventeenth century1, who To appreciate fully the qualities of a work of translated these as ‘firmness’, ‘commodity’ and architecture the critic or observer should ‘delight’. Subsequent theorists have proposed therefore know something of its structural different systems by which buildings may be make-up. This requires an intuitive ability to analysed, their qualities discussed and their read a building as a structural object, a skill meanings understood but the Vitruvian which depends on a knowledge of the breakdown nevertheless still provides a valid functional requirements of structure and an basis for the examination and criticism of a ability to distinguish between the structural building. and the non-structural parts of the building. ‘Commodity’, which is perhaps the most The first of these attributes can only be obvious of the Vitruvian qualities to acquired by systematic study of those branches appreciate, refers to the practical functioning of mechanical science which are concerned of the building; the requirement that the set of with statics, equilibrium and the properties of spaces which is provided is actually useful and materials. The second depends on a knowledge serves the purpose for which the building was of buildings and how they are constructed. intended. ‘Delight’ is the term for the effect of These topics are reviewed briefly in the the building on the aesthetic sensibilities of preliminary chapters of this book. those who come into contact with it. It may The form of a structural armature is arise from one or more of a number of factors. inevitably very closely related to that of the The symbolic meanings of the chosen forms, building which it supports, and the act of the aesthetic qualities of the shapes, textures designing a building – of determining its and colours, the elegance with which the overall form – is therefore also an act of various practical and programmatic problems structural design. The relationship between posed by the building have been solved, and structural design and architectural design can the ways in which links have been made take many forms however. At one extreme it is between the different aspects of the design are possible for an architect virtually to ignore all possible generators of ‘delight’. structural considerations while inventing the ‘Firmness’ is the most basic quality. It is form of a building and to conceal entirely the concerned with the ability of the building to structural elements in the completed version of the building. The Statue of Liberty (Fig. ii) at the entrance to New York harbour, which, given 1 Wooton, H., The Elements of Architecture, 1624. that it contains an internal circulation system xi Introduction of stairs and elevators, can be considered to be other than structure. The Olympic Stadium in a building, is an example of this type. The Munich (Fig. i), by the architects Behnisch and buildings of early twentieth-century Partners with Frei Otto, is an example of this. expressionism, such as the Einstein Tower at Between these extremes many different Potsdam by Mendelsohn (Fig. iii) and some approaches to the relationship between recent buildings based on the ideas of structure and architecture are possible. In the Deconstruction (see Figs 1.11 and 7.41 to 7.44) ‘high tech’ architecture of the 1980s (Fig. iv), for might be cited as further examples. example, the structural elements discipline the All of these buildings contain a structure, plan and general arrangement of the building but the technical requirements of the structure and form an important part of the visual have not significantly influenced the form vocabulary.