Design Engineering Refocused

ACKNOWLEDGEMENTS

We would first like to thank the directors and all the staff at AKT II, past and present; without them and their projects, this publication would not have been possible. It also goes without saying that this applies to all their clients, patrons and collaborators over the many years, as without them there would be no projects. We would also like to thank Professor John Ochsendorf for a considered and most welcome foreword. Hanif would like to single out Dean Mohsen Mostafavi at GSD for inspiring, advising and supporting this publication and for his poignant contribution ‘Future Focus’ at the start of this book.

To the authors who provided us with this book's exceptional content; Jordan Brandt, Marco Cerini, Diego Cervera de la Rosa, Philip Isaac, Jeroen Janssen, Sawako Kaijima, James Kingman, Alessandro Margnelli, Panagiotis Michalatos, Ed Moseley, Richard Parker, Andrew Ruck, Adiam Sertzu, Djordje Stojanovic, Edoardo Tibuzzi, Martijn Veltkamp and Marc Zanchetta.

Thanks, in particular, to Harvard University GSD and the AA, for encouraging us, but also to all the other institutions over the years.

We would like to thank Joshua Simpson and Kate Hobson for supervisory editing, Jan Friedlein, Erica Choi and Fritzie Manoy for graphic design, and Jessica Wainwright-Pearce for all the support in coordinating both internally and with the Wiley team.

Finally, we wish to thank our families for putting up with the late nights and long weekends during the construction of this book over the last two years.

FUTURE FOCUS

MOHSEN MOSTAFAVI

In architecture, the connection between the logic of a form and the logic of its structure always used to be thought of as direct, linear, and overtly rational. Right up to the latter part of the twentieth century, the principle of upright structural support, represented by vertical columns and horizontal beams, provided the dominant method for the conceptualisation and design of most buildings.

This Cartesian mode of imagining the reciprocities between form and structure, in all its many iterations, is of course still very much with us today. It continues to be the reference point for the vast majority of contemporary architectural projects, shaping our imaginations as well as the prevalent methods of the building industry, which in turn feed back into the design process through, for example, the considerations of cost and period of construction.

Buildings produced through a column grid structure can vary enormously in their systematic adherence to the relation between form and structure. But this relation was itself radically transformed during the second part of the twentieth century, with the evolution of concrete thin shell structures that brought about a synthetic unity between form and structure. Engineers such as Pier Luigi Nervi, Eduardo Torroja, and Felix Candela were instrumental in developing forms that were no longer purely reliant on traditional methods of building construction. In place of structure as form, they proposed the notion of form as structure.

Through its exploration of both the geometric properties of shell structures and the elastic qualities of reinforced concrete, the work of these engineers produced a radically different conception of architectural form. Their research resulted in spatial forms that at times seem to closely resemble shapes and patterns found in nature.

These developments in the field of engineering also have some parallels with the earlier work of the Scottish biologist and mathematician D'Arcy Wentworth Thompson, whose classic book On Growth and Form, first published in 1917, would become a primary source for subsequent studies of morphogenesis—the idea of forms and their connections with plants and animals. Similarly, one key consideration of the work presented in this book is the shift from linear to non-linear geometry. The structural behaviour of many contemporary designs no longer follows—or perhaps more importantly, necessarily needs to follow—traditional methods for calculating structural forces. In addition, technological advances have made it possible to both imagine and construct forms that previously would have been nearly impossible to conceive.

While often focused on the articulation of continuous skins and variations in the curvature of building envelopes, these explorations can nevertheless also be utilised to transform our traditional conceptions of architectural design and construction.

It is against this backdrop, and with advances made in computation, materials and fabrication procedures, that the contributions to this book have taken shape. Design Engineering Refocused proposes a new way of considering the hybrid relationship between design and engineering. For it is in the space of entanglement and reciprocities between these two types of practice that the authors have discovered innovative ideas and unexpected solutions that respond to typical programs and everyday needs of users and clients.

Mohsen Mostafavi is Dean of the Harvard Graduate School of Design and the Alexander and Victoria Wiley Professor of Design.

ENGINEERING AS EXPLORATION

JOHN OCHSENDORF

In his 2004 essay ‘In Search of Brunel’,1 architect Charles Correa lamented the hyper-specialisation of the contemporary engineer, having evolved from the visionary master builder of the past to the number-crunching designer of individual components of today. The great structural engineers of the late 19th and early 20th centuries, such as Isambard Kingdom Brunel, Gustave Eiffel and Robert Maillart, designed holistically to invent new technological possibilities. The vision of the pure engineer as lone genius, achieving beauty through the constraints of economy and efficiency, has been celebrated by Sigfried Giedion,² Le Corbusier,³ David Billington4 and many others over the past century. The structural engineer as singular artist applies most clearly to bridge design, where the challenge of spanning allows structure to dominate the design process. On the other hand, building design requires a level of synthesis among disciplines which does not often allow structure to emerge as the primary consideration, and it is therefore more difficult to identify examples of the heroic engineer in the design of buildings.

The profession of structural engineering is in a state of open crisis today. A Vision for the Future of Structural Engineering,5 published by the Structural Engineering Institute, identifies severe problems and characterises the field as occupying a ‘shrinking space’. It also highlights the challenges in structures education and laments that most undergraduate curricula have not changed in decades. Compared with the staggering pace of change in computing, biomedical engineering or nanotechnology, the field of structural engineering can seem frozen in time. So it is a challenging time for structural engineering. Engineers are asked to do more with less: to deliver more design options with lower costs and lower environmental impact. And to have fewer people design more complex projects in less time. Yet, within this landscape of crisis, there are numerous examples today of stellar structural engineers bringing value to design teams.

In characterising the interwoven roles of the architect and engineer, Le Corbusier defined this as a struggle between the ‘spiritual’ and the ‘economical’ (Figure 1). Design is an endless frontier. It requires finding a balance between the pragmatic and the sublime. Architectural education emphasises the plurality of solutions and encourages exploration. Engineering education emphasises unique solutions, which can lead to a reluctance to explore. But the greatest engineers are ceaseless explorers. Today, increased computational power is allowing engineers to shorten feedback loops in design by articulating a common language for design goals and by providing a clearer view of the terrain to be explored. Instead of providing a unique solution for the design team to accept or reject, the best engineers can map the design constraints in a productive way. The exploration of the engineer is bounded by ethics: by protecting human life in building safely; by pursuing design efficiency in a resource-constrained world; and by seeking economical solutions for clients within a finite budget. Without constraint, there is no design.

This is an optimistic book. It portrays a highly creative practice exploring new frontiers in structural engineering and it provokes questions on the multidimensional roles of engineering in contemporary architecture and art. Structure is not the only driver in architecture, nor should it be. But the projects and methods described here demonstrate the myriad ways in which the mature field of structural engineering can still contribute in new ways. The book demonstrates the powerful opportunities for engineers to serve as collaborative synthesisers in the endless frontier of design. The fearless exploration of AKT II exemplifies the burgeoning potential for the structural engineer in the 21st century. Brunel would be impressed.

John Ochsendorf is Professor of Civil and Environmental Engineering at the Massachusetts Institute of Technology. He became a MacArthur Fellow in 2008.

References

1 Charles Correa, ‘In Search of Brunel’, A Place in the Shade: The New Landscape and Other Essays, Penguin Books (Delhi), 2010, pp144–7.

2 Sigfried Giedion, Space, Time, and Architecture: The Growth of a New Tradition, Harvard University Press (Cambridge, MA), 1941.

3 Le Corbusier, Vers une architecture, Éditions Crès, Collection de ‘L'Esprit Nouveau’ (Paris), 1923.

4 David P Billington, The Tower and the Bridge: The New Art of Structural Engineering, Basic Books (New York), 1983.

5 A Vision for the Future of Structural Engineering and Structural Engineers: A Case for Change, ASCE: Structural Engineering Institute, 2013, http://www.asce.org/uploadedFiles/visionforthefuture.pdf

Images

Figure 1© FLC/DACS, 201

1The yin and yang of the architect and engineer, Le Corbusier, ‘Le Nouvel Aujourd'hui: les tâches de l'ingénieur et de l'architecte’, 31 May 1960.

PART 1: INTRODUCTION AND TERRAIN

HANIF KARA

Design engineering has become a cliché of seismic proportions with multifarious and slippery meanings. In order to reassert a coherent promise and to avoid getting caught in its propagation as a buzzword, this book establishes a precise meaning from the personal viewpoint of the editors based on the fundamental triumphs, experiences, methods and concepts developed at AKT II, a leading design-led, structural engineering practice. This is executed by dividing the book into two parts, ‘Introduction and Terrain’ and ‘Heft, Ontology and Horizon’ of design engineering, defined as an esoteric scientific discipline combined with visual stimuli. To make sense of the changes in design engineering and identify patterns, we have curated contributions from past and present colleagues over two decades, enabled by a combination of practice, design research and academic encounters which capture new technologies, analytical tools and processes that have emerged. We are careful not to be conclusive about the subject.

The first part of the book sets the pace by peeking at the recent past, but focusing on the present to paint a picture of a complex blend of high-tech, low-tech, old and new, digital and analogue, with sometimes contradictory outcomes that are the terrain of design engineering today.

1 THE PINK NOISE’ OF DESIGN ENGINEERING

HANIF KARA

The boundary and border of architecture and structural engineering have traditionally been defined by a linear and hierarchical correspondence between the two disciplines. Professionalisation of both disciplines has created a pre-articulated routinisation of the practices and distinct processes where the architect develops insights in design, while the structural engineer is granted exclusivity to react only once the design is developed. Today both are required to develop new skills and competences if they are to survive. In response to cultural and technological developments in the last twenty years, this relationship has evolved significantly, changing economic orders (where rising wealth has increased the importance of aesthetics) and, more recently, presenting new opportunities to question ‘planned obsolescence’ of buildings through the reshaping of design disciplines.

1 AKT II, birth of the structural engineer (c 1800).

Birth of the structural engineer and their position in the wider spectrum of architectural design discipline and history (which transcends our discipline).

The complex, changing relationship between the two disciplines cannot be explained easily, and any historical appraisal of the shifts could start in many places; we must therefore select the starting point of such a narrative carefully. Over the last century, the most compelling spark to questions concerning the dichotomy between ‘architect’ and ‘engineer’ as designers came from Le Corbusier in 1927, when many believe he asserted that the process of engineering should drive the development of architecture:

‘Engineers make architecture, since they use calculations that issue from the laws of nature, and their works make us feel HARMONY. So there is an aesthetic of the engineer, because when doing calculations, it is necessary to qualify certain terms of the equation, and what intervenes is taste. Now when one does calculations, one is in a pure state of mind and, in that state of mind, taste follows reliable paths.’¹

While one cannot agree with all of the implications inherent in Le Corbusier’s prescient statement, it was a strong encapsulation of the prevailing feelings of the time, and we can clearly trace their trajectory and legacy through the Modern and Post-Modern architectural movements, as exemplified by influential figures such as Ludwig Mies van der Rohe, Louis Kahn, Tadao Ando and Team 4 (Norman Foster, Richard Rogers, Su Brumwell and Wendy Cheesman), who each pushed for greater parity and collaboration between the two disciplines.

In subsequent decades, this cultural realignment was reinforced by profound changes in the field of structural analysis. Despite the crippling effects of the Second World War slowing progress in many areas of construction, a significant turning point occurred with the birth of the first threads of ‘limit state methods’. Driven by the greatly reduced availability of materials post-war, early experimental work in structural engineering conclusively demonstrated that analysis of stresses computed with simple elastic theory was far removed from how structures behaved, and from this emerged the concept of ‘plastic limit states’ that would erode and, in some instances, decompose factors of safety.

2 AKT II, evolution of reinforced-concrete design codes of practice. These codes have evolved since 1930, they assess how factors of safety, combined with new analysis, allow the reuse of old structures.

Though the gulf between the design of steelwork and reinforced-concrete structures remained, limit state methods advanced both materials. Notably in the UK between 1936 and 1948, the engineer John F Baker developed plastic theory for the design of steelwork, indeed it was used for the design of Morrison shelters during the war. While these methods are no longer used for simple structures today, the principles can be used for any buildings.

Meanwhile, in 1955 in the USSR, Professor NS Streleski developed methods of limit state design² that led to the introduction of the first codes in reinforced-concrete design using ultimate limit state method to reduce safety factors in concrete states (Figure 2). And, though not widely used until 1965, this has led to economical structural designs.

Such advances inspired new confidence that can be seen in the work of a long line of engineers since then; people such as Ove Arup, Ted Happold, Felix Samuely, Tony Hunt and Fazlur Khan, Cecil Balmond, Mike Schlaich, Jürg Conzett, Klaus Bollinger, William Baker and Peter Rice, all went on to broaden this incipient trend in the hope of spreading the value of a ‘creative collaboration’. Most significantly, Rice famously urged engineers to ‘imagine’ and temper the use of pragmatism to escape the characterisation of engineers as