The Structural Basis of Architecture

Bjørn N. Sandaker, Arne P. Eggen, Mark R. Cruvellier

• Publisher: Routledge
• Year: 2019
• Print ISBN: 9781138651982
• eBook ISBN: 9781317229179
• Edition: 3
• Topic: Architecture
• Subtopic: Architecture General

This is a book that shows how to "see" structures as being integral to architecture. It engages a subject that is both about understanding the mechanical aspects of structure as well as being able to relate this to the space, form, and conceptual design ideas that are inherent to the art of building.

Analyzing the structural principles behind many of the best-known works of architecture from past and present alike, this book places the subject within a contemporary context. The subject matter is approached in a qualitative and discursive manner, illustrated by many photographs and structural behavior diagrams. Accessible mathematical equations and worked-out examples are also included so as to deepen a fundamental understanding of the topic.

This new, color edition's format has been thoroughly revised and its content updated and expanded throughout. It is perfect as either an introductory structures course text or as a designer's sourcebook for inspiration, for here two essential questions are addressed in parallel fashion: "How do structures work?" and "What form do structures take in the context of architecture – and why so?" A rich, varied and engaging rationale for structural form in architecture thus emerges.

CHAPTER 1
Structuring Space

1.1 Structure as Spatial Generator and Mechanical Object

1.2 Spatial Aspects

1.3 Mechanical Aspects

Illustration 1.1
Galleria Vittorio Emanuele II, Milan, Italy (1865-1877).
Prominently sited on the northern side of the Piazza del Duomo, this galleria is a covered double arcade formed by two glass-covered vaults at right angles to each other and intersecting in a domed, octagonal central space.
Architect: Guiseppe Mengoni.

1.1 Structure as Spatial Generator and Mechanical Object

While it is easy to imagine structures without architecture, there can be no architecture without structures. Examples of the first category include construction cranes and transmission towers - structures whose sole purpose it is to keep loads lifted up off the ground. In architecture, the design of buildings commonly includes roofs, floors, and walls whose weight must also be borne and balanced by the help of structures. But beyond that, these elements are typically informed by requirements and conceptual ideas for their interior spaces and exterior forms. Structural issues, therefore, are inherently deeply embedded in architecture. The specific relationship between architecture and structure, however, whereby the one encompasses the other, may vary greatly from one architectural epoch to the next, or even from one building to another within the same time period. Today we are likely both to encounter buildings whose structures are of minor interest for architectural expression as well as others that display a particularly close correlation between structural form and its negative imprint, architectural space.

In order to shed some light on the particular connections that exist between structures and architecture, we first need to establish what we consider to be basic structural functions. Toward this end, we may ask: What purpose does the structure serve? What requirements govern the conditions establishing its overall and detailed form, and in what way do these conditions relate to one another? Addressing such questions allows us not only to develop a broad overview of the technical subject matter but also fosters a deeper understanding of what structures really are and how they can be assessed within the context of architectural design.

A fundamental point to be established from the beginning is that structures in architecture are conceived - and perceived - differently from structures in other contexts, and so they should be evaluated differently. In reflecting on the integral relationship that exists between structures and architectural spaces, forms, and ideas, certain issues arise that differentiate the structures of architecture from structures of other kinds. The most obvious and basic function of a structure is its capacity to keep something above the ground by bearing loads, and the practical use gained from that capacity is to keep floors, walls, and roofs in an elevated position, thereby establishing inhabitable spaces. In many cases in architecture, however, structures are not solely associated with such load-bearing functions. And while engineering is able to solve the necessary safety requirements, the door is luckily left wide open for making the structure even more deeply considered conceptually. Ideally, a close relationship is established between structure, space, and formal expression so that describing and characterizing a structure solely in terms of its load-bearing function is clearly insufficient. To understand structures in a wider sense as being part of an architectural context also means seeing their forms as space-defining elements, or as devices that modulate the amount and quality of daylight, or that reflect today's sustainability concerns, or any number of other assigned functions. Structures can serve many purposes simultaneously to carrying loads, therefore, and we need to keep this in mind not only to enable a more profound understanding of the development of structural forms but also to undertake an appropriate and informed critique of structures within an architectural context.

How can one go about establishing a conceptual model for such a holistic understanding of structures? As a starting point, we can observe that structures play a role both as a provider of necessary stiffness and strength (which are the basic mechanical prerequisites for carrying load safely), and as an instrument for creating architectural spaces that embody certain other qualities. This notion of a dual function, both mechanical and spatial, proves rewarding when it comes to understanding and appreciating the multifaceted design of structures in various architectural settings. Structures range from those conceived of as pure force systems that follow a logic of maximum strength for a minimum of materials (i.e., structural efficiency), to those designed to act iconographically as visual images. On the one hand there is a load-bearing function, which helps to explain structural form from the point of view of technology and science, as objects required to supply stiffness, strength, and stability, while on the other the structure may take part in the organization of architectural spaces and the establishment of an architectural expression. Moreover, these dual aspects of structure are not typically wholly separate from one another, but instead tend to mix and their divisions to blur so that certain formal features of a structure may both be explained by mechanics and also be understood in light of their spatial functions, (e.g., Ill. 1.2 and Ill. 1.3, 1.4.)

Illustration 1.2
Eames House (Case Study House No. 8), Pacific Palisades, CA, USA (1949).
Contrasting rather than adapting to the building site, the Eames House was intended to exploit off-the-shelf, prefabricated, industrial building components made of steel and make these applicable to residential design. Partly exposed, the steel structure orders the plan in modular bays of 2.4 by 6.4m (7.5 by 20ft). Quoting the architect: "In the structural system that evolved from these materials and techniques, it was not difficult to house a pleasant space for living and working. The structural approach became an expansive one in that it encouraged use of space, as such, beyond the optimum requirements of living." And: "it is interesting to consider how the rigidity of the system was responsible for the free use of space and to see how the most matter-of-fact structure resulted in pattern and texture."¹
Architect: Charles and Ray Eames. Structural engineer: Macintosh and Macintosh Company. Photographer: Julius Schulman. Title/date: [Eames House (Los Angeles, CA): exterior], [1950] © J. Paul Getty Trust.

Illustration 1.3
The Bordeaux House, Bordeaux, France (1998).
"Contrary to what you would expect," the disabled client told the architect, "I do not want a simple house. I want a complex house, because the house will define my world."² The house consists of three distinct levels: the lowest is cave-like - a series of spaces carved out from the hill for the most intimate life of the family. The highest level is divided into an area for the parents and another for the children. The most important level is almost invisible, sandwiched in between the other two: a glass room - half inside, half outside - that is used for living.
Architect: OMA/Rem Koolhaas. Structural engineer: Arup/Cecil Balmond.

Illustration 1.4 The Bordeaux House. A worm's-eye view diagram showing material elements and structural principles. Moving the supports outside the plan contributed to an opening up of the space.

This object/space duality can serve as a starting point but, as is the case with most conceptual models, it may simplify too much the world of real structures. Nevertheless, as long as we keep in mind that theoretical models of this kind can act as catalysts for increased insight while not necessarily being able to embrace absolutely every possibility, it will be found to be rewarding to identify both spatial function and mechanical function as the two prime concepts that establish the basis for a holistic understanding of structures in the context of architecture.

1.2 Spatial Aspects

The primary reason for the existence of structures is, of course, the practical purpose that they serve. Structures support loads from their location of application down to the ground, although typically not by means of the shortest possible "route" between those points since open and structure-free spaces of various sizes and shapes are needed in order to inhabit a building. This is the natural order of the relationship between the "why" and the "how," of reason and consequence: practical purpose comes first, and physical necessity follows. The practical purpose that the structure is assigned, its utility aspect, is fairly straightforward to accept and appreciate: in the case of bridges, for example, this is made clear by acknowledging the fact that the principal utility function, its "raison d'être" so to speak, is typically that of transporting people and goods across a valley, a river, or even an expanse of sea; i.e., it is all about establishing a transport line from one bank to the other. The straight line of communication that this link commonly results in will most likely suggest a certain structural configuration, either as a construct that becomes an integral part of the structural system, or else as setting up the conditions for how this line should be supported. The utility function provides in either case highly important input for how a structure is actually designed as well as an understanding of the form of bridge that is possible.

The same thing is generally true with the structuring of architectural spaces: the choice of a structural system and its particular articulation is highly dependent on the practical function that is associated with it. For example, in the case of the large beams at the top level of the Grande Arche de la Défense in Paris by architect Johan Otto von S...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Contents
• Dedication Page
• Preface
• Acknowledgments
• 1 Structuring Space
• 2 Introducing Structural Systems
• 3 Loads
• 4 Statics
• 5 Materials
• 6 The Hanger and the Tie
• 7 The Beam and the Slab
• 8 The Column and the Wall
• 9 The Truss and the Space Frame
• 10 The Frame and the Shear Wall
• 11 The Cable and the Membrane
• 12 The Arch and the Vault
• 13 The Dome and the Shell
• Notes
• Illustration Credits
• Bibliography and Suggested Reading
• Index (by Project Name)
• Index (by Subject)