Architecturally Exposed Structural Steel: Specifications, Connections, Details

TERRI MEYER BOAKE

Architecturally Exposed Structural Steel Specifications, Connec tions, Details

CONTENTS

The preparation of this book was kindly supported by the World Steel Association.

This book is now available for purchase!

Available through Amazon and other online retailers.

GRAPHIC DESIGN, LAYOUT AND TYPOGRAPHY Reinhard Steger, Christian Schärmer, Deborah van Mourik Proxi, Barcelona EDITOR FOR THE PUBLISHER Andreas Müller, Berlin LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA A CIP catalog record for this book has been applied for at the Library of Congress.

BIBLIOGRAPHIC INFORMATION PUBLISHED BY THE

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FOREWORD by Dr. Edwin Basson,

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AESS 4 – Showcase Elements

Director General,

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AESS C – Custom Elements

World Steel Association

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Mixed Categories

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CHAPTER 3

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PREFACE

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CHAPTER 1

THE BASIS OF ARCHITEC TURALLY EXPOSED STRUC TURAL STEEL

DEUTSCHE NATIONALBIBLIOTHEK The Deutsche Nationalbibliothek lists this publication in the Deutsche

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What is AESS?

Nationalbibliografie; detailed bibliographic data are available in the

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The Evolution of Architecturally

Internet at http://dnb.dnb.de.

Exposed Structural Steel

This work is subject to copyright. All rights are reserved, whether the

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reproduction on microfilms or in other ways, and storage in databases.

For any kind of use, permission of the copyright owner must be obtained.

Initial Developments in High Tech Detailing

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Primary Factors of Influence that Define AESS

This publication is also available as an 22

e-book pdf (ISBN 978-3-03821-483-0) and EPUB (978-3-03821-446-5).

Communication Issues between Architect, Engineer and Fabricator

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© 2015 Birkhäuser Verlag GmbH, Basel

AESS 1 – Basic Elements

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AESS 2 – Feature Elements with

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AESS 3 – Feature Elements with

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AESS 4 – Showcase Elements

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AESS C – Custom Elements

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Using the System

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AESS CATEGORY MATRIX

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CHAPTER 4

a View Distance > 6m/20ft a View Distance ≤ 6m/20ft

The Role of BIM and Detailing

EREC TION CONSIDERATIONS 63

Part of Walter De Gruyter GmbH, Berlin/Munich/Boston

Elements 64 65

Printed on acid-free paper produced from 25

chlorine-free pulp. TCF ∞

CHAPTER 2

THE CATEGORY SYSTEM

Printed in Germany ISBN 978-3-03821-574-5

Transforming an Architectural Idea into Prefabricated AESS

Software

P.O. Box 44, 4009 Basel, Switzerland

Shop versus Site Fabrication The Impact of Transport Issues on Design

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Site Constraints

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Care in Handling

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Sequencing, Lifting, Access and Safety

987 65 4 32 1 www.birkhauser.com

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To Grind or Not to Grind?

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Erecting the Steel

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Standard Structural Steel

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Combining AESS with Other

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AESS 1 – Basic Elements

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AESS 2 – Feature Elements with a View Distance > 6m/20ft

As a rule, this book does not make reference to existing patents, registered designs, trademarks etc. If such reference has been omitted, this does not signify that the product or the product name is not protected. The great number of different materials and products mentioned in this book made it impossible to carry out an investigation into the possible existence of trademark protection in every case. Accordingly, as a rule, the text makes no use of trademark symbols such as

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High Tech

whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcasting,

From Structural Rationalism to

CHARAC TERISTICS

®

or TM.

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AESS 3 – Feature Elements with a View Distance ≤ 6m/20ft

Systems

BUILDING PROFILES 75

CHAPTER 5

COATINGS & PROTEC TION 76

Surface Preparation

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Paint Systems

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Primers

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Shop versus Site-applied Coatings

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Corrosion Protection: Galvanization, Metallization,

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CHAPTER 7

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CONNEC TIONS 117

Definitions

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Connection Design Checklist

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Shop versus Site Fabrication

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Connection Mock-ups and Bolted Connections

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Welded Connections

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Pin Connections

Fire Protection Systems: Intumescent Coatings, Sprayed Fire-resistive Materials (SFRM), Concrete-filled Steel Tubes

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CHAPTER 6

MEMBER CHOICES

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CHAPTER 8

SPECIALIZED CONNEC TIONS 139

Making Connections Less Visible

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Hidden Connections

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Discreet Connections

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Cast Connections

The Texture of an AESS Project

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Choosing a Member Type

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Hot-rolled Steel Sections

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Tubular or Hollow Structural

CUSTOM FABRICATION

Structural Sections, Square or

CHAPTER 9

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Elliptical Hollow Sections (EHS)

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Custom-fabricated Sections

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Tapered Tubes or Cones

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Building Profiles

APPENDIX

ARGANZUELA BRIDGE

Porto, Portugal

ART Gateshead, England

Madrid, Spain

ICQ with WS Atkins

Ellis Williams Architects

Dominique Perrault

WESTGATE PEDESTRIAN AND CYCLE

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SYDNEY OPERA HOUSE

BRIDGE Auckland, New Zealand

Sydney, Australia

Jasmax architects, Aurecon

Jørn Utzon and Ove Arup

Construction

de Ingeniería, S.L. 168

ORIENTE STATION Lisbon, Portugal

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AMGEN HELIX BRIDGE

Santiago Calatrava

Seattle, WA, USA 86

87

STRATFORD TOWN CENTRE LINK

Johnson Architecture and KPFF

London, England

Consulting Engineers

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THE GLASS BRIDGE

Santiago Calatrava 160

CANOE BRIDGE

Vancouver, BC, Canada

170

PWL Partnership Landscape

Newcastle, England

Donaldson + Warn; Capital House

Architects

Wilkinson Eyre Architects with Gifford

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VIADUCT EVENTS CENTER Auckland, New Zealand

John Holland Constructions

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ONTARIO COLLEGE OF ART AND DESIGN Toronto, ON, Canada

Cecil Balmond 162

Will Alsop Architect BARAJAS AIRPORT TERMINAL 4

THE SHARD OBSERVATION LEVEL London, England

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ABC MUSEUM

Renzo Piano Building Workshop

Madrid, Spain

and WSP

Aranguren + Gallegos

Madrid, Spain Rogers Stirk Harbour + Partners

Arquitectos 163

THE NEW YORK TIMES BUILDING New York City, NY, USA

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152

NEO BANKSIDE HOUSING

Renzo Piano Building Workshop,

London, England

FXFOWLE Architects and

Rogers Stirk Harbour + Partners

Thornton Thomasetti

BRISBANE INTERNATIONAL

PEDRO AND INÊS BRIDGE Coimbra, Portugal

Moller Architects

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GATESHEAD MILLENNIUM BRIDGE

Perth, Australia

Kevin Draper and Richard Walley;

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PEACE BRIDGE Calgary, AB, Canada

Engineers; artists David Jones,

Rectangular Hollow Structural Sections

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Knight Architects with Buro Happold

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Sections (HSS): Round Hollow

BALTIC CENTRE FOR CONTEMPORARY

Consulting Engineers and HEB

Stainless Steel, Weathering Steel 89

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Architecture with MC2 Estudio 83

Visual Samples 122

PORTO INTERNATIONAL AIRPORT

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NATIONAL ARCHIVES OF CANADA

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ST. JOHN AMBULANCE HEADQUARTERS

Edmonton, AB, Canada Manasc Isaac Architects

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BOSTON SOCIETY OF ARCHITECTS

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Selected Bibliographic

AIRPORT Brisbane, Australia

Gatineau, QC, Canada

STAIR Boston, MA, USA

References

Richards and Spence with Arkhefield

Blouin IKOY & Associés

Höweler + Yoon Architecture

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Notes

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Illustration Credits

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Subject Index

BERLIN Berlin, Germany

OFFICE BUILDING

Madrid, Spain

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Index of Buildings

Architekten von Gerkan,

London, England

Herzog & de Meuron

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Index of Persons and Firms

Marg und Partner

Foggo Associates

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About the Author

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RENOVATION OF OLYMPIASTADION

REGENT PALACE HOTEL

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CANNON STREET STATION AND

PUENTE DE LUZ

London, England

Toronto, ON, Canada

Dixon Jones Architects

Francisco Gazitua

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CAIXA FORUM

FOREWORD The World Steel Association (worldsteel) is proud to be the exclusive sponsor of Architecturally Exposed Structural Steel: Specifications, Connections, Details. Construction is one of the most important steel-using industries, globally accounting for more than 50% of world steel use. Buildings – from houses to car parks to schools to skyscrapers – rely on steel for their strength and durability. In addition to structural frameworks, steel is also used on many other parts of buildings, including roofs and cladding for exterior walls.

Steel continues to be at the root of advances in architecture and construction. The use of exposed steel in buildings brings the design benefits and dynamic potential of steel to the public eye. Its stiffness allows steel to span greater distances and provides more design freedom than other materials. Steel’s superior strength-to-weight ratio makes it possible for the structure to bear high loads using less material. Architecturally Exposed Structural Steel (AESS) plays a significant role also in the design of contemporary pedestrian bridges that elevates their role in the urban realm to that of art.

Sustainable steel is at the core of a green economy. Reusing or recycling building components is key to the sustainability of a structure’s end-of-life as it is the most economic and ecological solution. The global recovery rates for steel construction applications stand at 85%, making it a good choice for building structures. The exposure of steel leads to a reduction of materials that would otherwise be used to conceal the structural systems, while at the same time creating stimulating architecture.

Steel is safe, innovative and progressive. Industry surveys consistently demonstrate that steel is the safest construction material. Steel offers the highest strength-to-weight ratio of any building material. Because of its strength and durability, steel structures are designed to withstand natural disasters. It is also impervious to attacks from termites or fungi, does not rot or split and is highly fire-resistant. The steel industry globally spends more than €12 billion annually on improving the manufacturing processes, new product developments and future breakthrough technologies.

Steel is a key driver of the world’s economy. The industry directly employs more than two million people worldwide, with a further two million contractors and four million people in supporting industries. In 2013, the steel industry had a turnover of more than $900 billion, yielding over $100 billion in tax.

Steel plays a fundamental role in the development of modern societies and is an ideal material to help meet the societies’ growing needs for buildings and infrastructures in a sustainable way. Its intrinsic properties such as its strength, versatility, durability and 100% recyclability allow improved environmental performance across the entire life cycle of buildings.

The Munich Airport Center in Munich, Germany, designed

by Helmut Jahn and completed in 1999, showcases high-level detailing in Architecturally Exposed Structural Steel.

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The AESS Category System of design presented in this book acknowledges the importance of the role of proper connection design and erection strategies, and communication between the fabricator, engineer and architect, as central to ensuring safety on the site.

Dr. Edwin Basson

Director General, World Steel Association

PREFACE ACKNOWLEDGMENTS This publication has been made possible through the generous support of worldsteel. Worldsteel was also the sponsor of Diagrid Structures: Systems,

Connections, Details.

My early interest in steel must be credited to inspiration from the High Tech works of Foster, Rogers, Piano and Grimshaw as well as Santiago Calatrava.

My appreciation of the importance of the details of these connections as elements of industrial design was inspired by my former colleague at the University of Waterloo School of Architecture, Ron Keenberg of IKOY Architects.

Much of my energy and understanding of Architecturally Exposed Structural Steel comes through my involvement with the Canadian Institute of Steel Construction in the development of the methodology that is expanded upon in this book. I owe so much to the large number of steel professionals involved in this development. Particular thanks go to Mike Gilmor, Rob Third and Suja John.

Also core to the CISC AESS committee work, my understanding and experience of steel would be nowhere without the assistance of Sylvie Boulanger, Walter Koppelaar and Tim Verhey. Sylvie is my engineering counterpart and has willingly shared so much knowledge and insight with me. Sylvie traveled with me to Australia and New Zealand in conjunction with expanding the Category System to Australasia. Walter has always encouraged me and allowed me into his fabrication shop, and provided access to numerous job sites and high-quality projects. Without these detailed first-hand experiences of construction in process, my expertise would not have progressed beyond that of a standard instructor and my image bank would be substantially poorer. Tim Verhey was always willing to provide me with very detailed technical clarifications, many of which are included in this book.

Thank you to Alistair Fussell of Steel Construction New Zealand and David Ryan of the Australian Steel Institute for hosting Sylvie and me and providing access to some excellent steel projects, many of which are included in this book.

Thanks as well to my editor Andreas Müller for his expertise, input and support and to Reinhard Steger and his team for their loving attention to the graphic layout of this book.

Lastly to my family for the continued support of and pride in my publication endeavors.

Ronald Reagan National Airport in Washington, DC, USA, designed by Pelli Clarke Pelli Architects, demonstrates the possibilities of AESS using a highly angular aesthetic. Here the curves are faceted. Much of the high-level steel makes use of simple structural shapes. A combination of remediated welded connections is mixed with exposed bolting.

The extensive use of natural light successfully animates the technical appearance of the steel.

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I have found great joy and inspiration in the detailed study of Architecturally Exposed Structural Steel (AESS) that has ensued from the research and writing I undertook for my first book Understanding Steel Design: An Architectural Design Manual, published

by Birkhäuser in 2011. Where Understanding Steel Design looked more holistically at the potential in the informed use of steel in architectural projects, Architecturally Exposed Structural Steel looks more specifically at an approach to properly designing steel for exposure. Such exposure demands that architects become more engaged in the detailed design of steel systems, and with that, understand better the varying approaches to connection design, fabrication and finishing and how these impact the entire project in significant ways.

The category approach to specifying and detailing AESS that is presented in this book is derived from substantial work done in conjunction with the Canadian Institute of Steel Construction (CISC) between 2005 and 2011. The development of this system by CISC was intended to create better communications within projects in order to make the incorporation of AESS more straightforward by standardizing some of the core fabrication and detailing practices, thereby allowing the team to focus on the “real questions”. The method has subsequently been adopted in New Zealand and Australia and I am working with a large team in association with the American Institute of Steel Construction (AISC) to create a unified approach to AESS practices additionally between the USA and Canada.

The photos included in this book were predominantly taken by myself during building visits. As the design of AESS strongly focuses on the details of finished steel, it was essential that the derivation of the Category System be done through first-hand experience, as it is the best means to validate the characteristics of projects. Certain project images taken during fabrication processes where I was unable to be present, have been sourced from the team members. These are credited at the back of this book.

Penny Lane (2012) Gibbs Gage Architects

Preface

STRUCTURE OF THE BOOK Architecturally Exposed Structural Steel (AESS) is seeing increased and widespread use around the world. AESS is steel that is a purposefully expressed part of the architectural design of a building and subject to normal views by pedestrians or occupants of a building. It must simultaneously satisfy aesthetic and structural requirements, hence placing itself strategically to include architecture and engineering. Its use was derived from High Tech Architecture and has come to be part of the mainstream of the use of steel in architectural design. Because it is clearly visible, AESS is subject to closer tolerances than standard steel that is hidden from view, and therefore requires special consideration during the design phase of a project. AESS requires a much higher level of communication between the architect, engineer and fabricator in order to select details that are appropriate to the finish, fire protection system and class of the structure.

There are clear advantages to the use of AESS: - the exposed steel can be an expressive part of the architecture of the building in addition to providing structural support - when steel is exposed it often obviates the need for other finishes, such as gypsum board - exposed systems when they reduce the requirement for other finish materials can reduce the carbon costs and environmental footprint of the building - many of the types of steel systems that are used in AESS, such as tension, lattice and other specialty glazing support systems, create architectural interest in the project The architectural challenge in AESS lies in details and connections.

Also, AESS is greatly concerned with and affected by the choice of finish and detailing. The current thinking recognizes that the type (expense) of detailing needs to be warranted by proximity to view as well as building function. There is no economic sense in overworking details that will not be able to be “seen”. For these reasons, the book will tend to focus on these issues through the use of many close-up photographs, photos being more useful than drawings or diagrams in this context, in order that the reader can really “see” the nature of the connection and level/type of finish.

The book will be structured in two parts.

The first half of the book will create a comprehensive understanding of the differentiated categories of AESS and how these are impacted by the selection of steel shapes, connection detailing, fabrication methods, erection and finishing. The second half of the book will focus on applications in AESS, to include some recent projects selected from around the world to be very geographically inclusive as well as to emphasize the global nature of AESS. The projects will include some innovative tension structures, exposed structural systems and pedestrian bridges. There will be a focus on the design of the connections rather than a focus on the creation of the overall systems.

Milwaukee Art Museum (2001) Santiago Calatrava

1. Introduction

INTRODUCTION The first chapter of the book will provide a general introduction to Architecturally Exposed Structural Steel to establish the basis for the balance of the text. Most importantly this will look at the difference between the use of regular carbon steel in a concealed fashion and highlight the potential in the architectural use of steel in an exposed and expressed fashion.

Sub headings will include: - What is AESS? - The Evolution of Architecturally Exposed Structural Steel - Primary Factors of Influence that Define AESS - Communication Issues between Architect, Engineer and Fabricator - The Role of BIM and Detailing Software

AESS for atriums and skylights

AESS for pedestrian bridges

Specialty AESS applications

PART ONE: UNDERSTANDING AESS DESIGN

The Sage Gateshead (2004) Foster and Partners

2. Categories of AESS

CATEGORIES OF AESS This chapter will set out the Category System for classifying Architecturally Exposed Structural Steel. This system originated in the United States (developed by AISC), was further detailed and clarified by the Canadian Institute of Steel Construction, and has been adapted and adopted by Australia and New Zealand.

There is a very clear link between the design goals of the system and the creation of an economy in use through effective communication. Particularly with areas of depression in the Global economy, this method strives to put effort and expense where it will be most valuable.

Sections will include: - The Categories Approach - Standard Structural Steel as the base mode - AESS 1 - Basic Elements - AESS 2 - Feature Elements (view distance > 6 meters) - AESS 3 - Feature Elements (view distance ≤ 6 meters) - AESS 4 - Showcase Elements - AESS C - Custom Elements - Mixed Categories The example projects used in Part One: Understanding AESS Design will be intentionally varied in terms of size, application and “fame”. The intention is to showcase the possible variety of applications, including some very exquisite ones that might not be very well known. The reader should find a rich set of examples in this book that they can use for inspiration and detailing ideas.

Ottawa International Airport

Gaylord Resort, Dallas

Bus Shelter using galvanized

Winter Garden - World Financial Center (2012) CĂŠsar Pelli and Associates

3. Characteristics of Fabrication

CHARACTERISTICS OF FABRICATION This chapter will go into detail regarding the specific fabrication characteristics that should follow each of the AESS Categories described in the preceding chapter. There is a prescribed additive sequence, from the most basic steel in the AESS1 Category, up to the highest level AESS 4 steel.

Characteristics of Fabrication as Related to the Categories - Surface Preparation Requirements - Cutting and Edge Finishing - Welding vs Bolting - Tolerances And finally: - To Grind or not to Grind, that is the Expensive Question

Cutting Techniques

To grind, or not?

Revealing welds for effect!

Winter Garden - World Financial Center (2012) CĂŠsar Pelli and Associates

4. Erection Considerations

ERECTION CONSIDERATIONS This chapter will go into detail regarding the erection issues that must be addressed when constructing with AESS. A much higher level of care in handling is essential in order to ensure that the surface of the steel does not get unduly damaged during construction. Surface damage will have to be repaired or it will translate through to the final finish.

Erection Considerations: - Handling the Steel - Transportation Issues - Sequencing of Lifts - Site Constraints - Erection Issues

Shanghai Tower

Truss erection, Australia

Padded slings to protect

Pedestrian Bridge, Vancouver (2011)

5. Coatings and Finishes

COATINGS AND FINISHES This chapter will go into detail regarding the impact of finish and coatings on the detailed design of AESS structures. Finish must be known at the outset of the project.

Topics will include: - General Issues - interior vs. exterior applications - finish vs. corrosion protection - Surface Preparation - Painting and Primers - Shop versus Site Painting - Intumescent Coatings - Galvanizing - Weathering and Color Selection (when white may not be right) As a good deal of AESS is being used in exterior applications, the issue of detailing for corrosion protection and maintenance will be stressed. Poor finishes on projects can result in bad public relations and it is in the architect’s best interest to design with maintenance in mind.

EMP - Gehry

Wembley Stadium - Foster

Guangzhou Stadium

PART TWO: AESS APPLICATIONS

Residential Complex, London (2011)

6. Designing Connections

DESIGNING CONNECTIONS This chapter will go into detail regarding the design of connections. Connections are a key aspect of the architectural flavor of the project and unlike Standard Structural Steel, cannot be left to the discretion of the consulting engineer. Architects do however need to understand how the loads are transferred through the connections as well as the issues that will be addressed regarding member selection and connection methods.

Topics addressed will include: - General Issues - Connection Mock-Ups - Which Type of Connection Should I Choose?

- Bolted Connections - Welded Connections - Tubular Steel (RHS/CHS) - Elliptical Sections (EHS) - Cast Connections The intent of this chapter is to include a very large selection of close up detail photos of buildings rather than looking at overall projects. The images are intended to be large enough in format to be very informative and revealing.

The idea behind this chapter is to show that there are many different choices that can be made regarding connection design.

Feature Stair - Boston Society of Architects

Ottawa Airport

Seattle Museum of Flight

Poly Plaza, Beijing (2007) SOM Architects

7. Tensile Systems

ELEMENTS AND CONNECTIONS FOR TENSILE SYSTEMS This chapter will go into detail regarding the design of connections that are used in tensile systems. This will include tensile applications for buildings as well as for glazing support systems.

Topics addressed will include: - Tension specific connectors - Structural supports with tension - Canopies and cantilevers - Hybrid tension and compression systems - Supporting glazing with tension The chapter will highlight projects but focus more on the methodology and design of the tension systems as they follow the AESS guidelines and method of detailing.

Shanghai Tower - atrium suspension system

Hanging pods, Shanghai

Wisconsin Museum of Art

Cannon Street Station, London (2012) Foggo Associates

8. Long Spans and Cantilevers

ELEMENTS AND CONNECTIONS FOR LONG SPANS AND CANTILEVERS This chapter will go into detail regarding the design of connections that are used in a wide variety of AESS applicatons, including long spans, cantilevers, trusses and other projects not captured in “tensile systems” and “pedestrian bridges”.

These applications would include atriums, large interior spaces, sports facilities, canopies and other complex building applications.

The focus will be on connections and providing the reader with close up examples of multiple ways of approaching detailing - again reflecting on the Category approach in order to allow for proficiency in selecting methods that are aesthetically pleasing but also economically viable.

Many of the projects that will be used in this chapter were created by “other than star architects”. Where buildings by Foster, Rogers and Calatrava will be included, these are normally fairly high end buildings with large budgets. The idea of the book is to demonstrate that much can be achieved with less expensive detailing.

Connections discussion will look at issues related to the choice to bolt or weld the steel and the approaches that are possible to reduce site related erection issues through connection design.

Wembley Stadium

Penny Lane

Abilities Center

Pedestrian Bridge, Toronto (2012)

9. Pedestrian Bridges

ELEMENTS AND CONNECTIONS FOR PEDESTRIAN BRIDGES This chapter will go into detail regarding the design of connections that are used in a wide variety of AESS applicatons of pedestrian bridges. Small bridge projects have seen a huge uptake by architects. These present the potential for additional work for architects given the similarity of scale to other building related long span types (previous chapter). The AESS connections for these are in some instances unique to bridge issues, so need to be addressed, and in other cases, easily transferred to other project types. Detailing for corrosion resistance is important. The bridge projects will be sourced from a mix of well known projects to lesser known ones that use exemplary details, again to illustrate the different approaches to design that can be used for economical reasons.

Rolling Bridge, Paddington Basin

Peace Bridge, Calgary

Aviation Museum, Seattle

Gateshead Millennium Bridge, Newcastle

Pedestrian Bridge, Canary Wharf

Highway overpass, Vancouver