Structure and Architecture

Angus J. Macdonald

• Éditeur: Routledge
• Année: 2018
• ISBN:
  9781351809870
• Édition: 3
• Sujet: Architecture
• Sous-sujet: Architecture General

This thoroughly updated edition of Angus J. Macdonald's insightful book Structure and Architecture offers an in depth analysis of structural design and its relationship with architecture. It draws on clear explanations of the connections between structural form, structural performance and architectural design to explore the interface between the technical and the visual in architecture. Additional chapters in this new edition cover the fields of structural theory, structural philosophy, the contributions of prominent engineers to the evolution of Modern architecture, and the concept and practice of sustainable design. Fully illustrated, this critical appraisal of structures is a core-curriculum text for students of architecture, structural engineering and architectural history, and is also a valuable resource for practitioners of these disciplines.

CHAPTER 1

The relationship of structure to building

Pantheon, Rome. Painting: Panini.

The simplest way of describing the function of an architectural structure is to say that it is the part of a building that resists the loads that are imposed on it. A building may be regarded as simply an envelope that encloses and subdivides space in order to create a protected environment. The surfaces that form the envelope, that is the walls, the floors and the roof of the building, are subjected to various types of loading: external surfaces are exposed to the climatic loads of snow, wind and rain; floors are subjected to the gravitational loads of the occupants and their effects; and most of the surfaces also have to carry their own weight (Figure 1.1). All of these loads tend to distort the building envelope and to induce it to collapse; it is to prevent this from happening that a structure is provided. The function of a structure may be summed up, therefore, as being to supply the strength and rigidity that are required to prevent a building from collapsing. More precisely, it is the part of a building that conducts the loads that are imposed on it from the points where they arise to the ground underneath the building, where they can ultimately be resisted.

Figure 1.1 Loads on the building envelope. Gravitational loads due to snow and to the occupation of the building cause roof and floor structures to bend and induce compressive internal forces in walls. Wind causes pressure and suction loads to act on all external surfaces.

Figure 1.2 The igloo is a self-supporting compressive envelope.

Figure 1.3 In the tepee a non-structural skin is supported on a structural framework of timber poles.

Figure 1.4 Exhibition Hall of the CNIT, Paris, 1958; Nicolas Esquillan, engineer. The principal element is a self-supporting reinforced concrete shell.

Photo: David Monniaux/Wikimedia Commons.

The location of the structure within a building is not always obvious because the structure can be integrated with the non-structural parts in various ways. Sometimes, as in the simple example of an igloo (Figure 1.2), in which ice blocks form a self-supporting protective dome, the structure and the space enclosing elements are one and the same thing. Alternatively, the structural and space-enclosing elements can be entirely separate. A very simple example is the tepee (Figure 1.3) in which the protecting envelope is a skin of fabric or hide that has insufficient rigidity to form an enclosure by itself and that is supported on a framework of timber poles. Complete separation of structure and envelope occurs here: the envelope is entirely non-structural and the poles have a purely structural function.

Figure 1.5 Modern Art Glass Warehouse, Thamesmead, UK, 1973; Foster Associates, architects; Anthony Hunt Associates; structural engineers. A non-structural skin of profiled metal sheeting is supported on a steel framework, which has a purely structural function.

Photo: Andrew Mead.

The CNIT exhibition hall in Paris (Figure 1.4) is a sophisticated version of the igloo; the reinforced concrete shell that forms the main element of this enclosure is self-supporting and therefore structural. Separation of skin and structure occurs in the transparent walls, however, where the glass envelope is supported on a structure of mullions. The roof of the Centre Pompidou building at Metz (Figure 11.6), the overall form of which was largely determined by the requirements of its lattice-timber ‘shell’ structure, is similarly configured although in this case the timber structural elements are distinct from the enclosing roof surface that it supports and the building is therefore similar to the tepee in its separation of structural from enclosing elements.

The steel frame warehouse by Foster Associates at Thamesmead, UK (Figure 1.5), is almost a direct equivalent of the tepee. The elements that form it are either purely structural or entirely non-structural because the corrugated sheet metal skin is entirely supported by the steel frame, which has a purely structural function. A similar breakdown may be seen in later buildings by the same architects, such as the Sainsbury Centre for the Visual Arts at Norwich, UK (Figures 9.33 and 9.34) and the warehouse and showroom for the Renault car company at Swindon (Figure 3.19).

In most buildings the relationship between the envelope and the structure is more complicated than in the above examples and frequently this is because the interior of the building is subdivided to a greater extent by internal walls and floors. For instance, in Foster Associates’ building for Willis, Faber & Dumas (WFD), Ipswich, UK (Figures 1.6 and 5.16) the reinforced concrete structure of floor slabs and columns may be thought of as having a dual function. The columns are purely structural, although they do punctuate the interior spaces and are space-dividing elements, to some extent. The floors are both structural and space-dividing elements. Here, however, the situation is complicated by the fact that the structural floor slabs are topped by nonstructural floor finishing materials and have ceilings suspended underneath them. The floor finishes and ceilings could be regarded as the true space-defining elements and the slab itself as having a purely structural function. The glass walls of the building are entirely non-structural and have a space-enclosing function only.

The Solaris Building in Singapore by Ken Yeang, with Arups as engineers, (Figures 1.7 and 1.8) is also supported by a reinforced concrete structure. Here the structural continuity (see Glossary) and mouldability that concrete offers were exploited to create a complex juxtaposition of solid and void. The building is of the same basic type as the WFD building however: a structural framework of reinforced concrete supports cladding elements that are non-structural.

In the Centre Pompidou in Paris by Piano and Rogers a multi-storey steel framework is used to support reinforced concrete floors and non-loadbearing glass walls. The breakdown of parts is straightforward (Figs 9.28 to 31): identical plane-frames, consisting of long steel columns which rise through the entire height of the building supporting triangulated girders at each floor level, are placed parallel to each other to form a rectangular plan. The concrete floors span between the triangulated girders. Additional small cast-steel girders project beyond the line of columns and are used to support stairs, escalators and servicing components positioned along the sides of the building outside the glass wall, which is attached to the frame near the columns. A system of cross-bracing on the sides of the framework prevents it from collapsing through instability. In this type of building the structure not only provides support but makes a significant contribution to the visual aspects of the architecture.

Figure 1.6 Willis, Faber & Dumas Office, Ipswich, UK, 1974; Foster Associates, architects; Anthony Hunt Associates, structural engineers. The basic structure of this building is a series of reinforced concrete coffered slab floors supported on a grid of columns. The external walls are of glass and are non-structural. In the finished building the floor slabs are visible only at the perimeter. Elsewhere they are concealed by floor finishes and a false ceiling.

Photo: A. Hunt.

The free form, in both plan and cross-section, of the Riverside Museum in Glasgow by architect Zaha Hadid (Figures 1.9 and 10.25 and 26), make it in some respects a complete contrast to the controlled order of the C...