The DEVELOPMENT of a NEW LANGUAGE OF

STRUCTURES in ARCHITECTURE

during the second half of the 20th century

(with student case studies)

For SAP2000 problem solutions refer to “Wolfgang Schueller: Building

Support Structures – examples model files”:

https://wiki.csiamerica.com/display/sap2000/Wolfgang+Schueller%3A+Building+Su

pport+Structures+-

If you do not have the SAP2000 program get it from CSI. Students should

request technical support from their professors, who can contact CSI if necessary,

to obtain the latest limited capacity (100 nodes) student version demo for

SAP2000; CSI does not provide technical support directly to students. The reader

may also be interested in the Eval uation version of SAP2000; there is no capacity

limitation, but one cannot print or export/import from it and it cannot be read in the

commercial version. (http://www.csiamerica.com/support/downloads)

See also,

(1) The Design of Building Structures (Vol.1, Vol. 2), rev. ed., PDF eBook by

Wolfgang Schueller, 2016, published originally by Prentice Hall, 1996,

(2) Building Support Structures, Analysis and Design with SAP2000 Software, 2nd

ed., eBook by Wolfgang Schueller, 2015.

The SAP2000V15 Examples and Problems SDB files are available on the

Computers & Structures, Inc. (CSI) website:

http://www.csiamerica.com/go/schueller

This presentation will introduce the new generation of structures

that has developed primarily during the 1950s to about 1990. It is

emphasized that structure is architecture and not just plugged

into architectural space.

I will concentrate on the experience of building structures from a

visual point of view primarily, as seen through the eyes of a

design engineer and architect, rather than a detailed discussion

of structural behavior, refinement of structural performance, or

efficient construction methods. In other words, this lecture will

celebrate the joy of structures as architecture and

engineering art.

The cases are shown in the context of education as unique

solutions, which demonstrate the complexity and creative mind

of designers and express the infinite richness of architectural

form.

I like to briefly remind you of the basic position of the structural engineer

which often is perceived by architects as a very narrow one. The structural

engineer is responsible for safety, to him the building is a body that is alive,

its bones and muscles are activated by external and internal forces. As

it reacts, it deforms and suggests the pain it must endure at points of stress

concentration.

The arrangement of space, which defines members and their spans,

becomes most important in controlling the force flow to the foundations and

reducing stress concentrations to a minimum. In other words, engineers

visualize buildings in an animated state moving back and forth as can

be convincingly expressed by computers through virtual modeling.

In contrast architects must respond in the design of buildings to the

broader issues of the environmental context, be it cultural or physical.

I like to emphasize that the theme of my presentation is not addressing the

difference between structural engineers and architects is, but that

STRUCTURE DOES NOT ONLY PROVIDE SUPPORT BUT ALSO CAN

BE ARCHITECTURE.

A. Introduction:

S T R U C T U R E I S A R C H I T E C T U R E

First I like to remind you that the development of modern building

support structures has its origin in the inventive spirit of structural

engineering and the rapid progress in the engineering sciences during

the 19th century, as reflected by:

• The enormous volume of the iron-glass structure system of the

Crystal Palace in London (1851, Joseph Paxton), constructed in the

short period of only six months.

• The longest span of 480 m (almost 1600 ft) of the Brooklyn Bridge in

New York (1883, John and Washington Roebling),

• The unbelievable height of the 300 m Eifel Tower (nearly 1000 ft) in

Paris (1889, Gustave Eifel)

The unbelievable height of the 300 m

Eifel Tower (nearly 1000 ft) in Paris

(1889, Gustave Eifel)

The longest span of 480 m (almost 1600 ft) of the Brooklyn

Bridge in New York (1883, John and Washington Roebling),

The enormous volume of the iron-glass structure system

of the Crystal Palace in London (1851, Joseph Paxton),

constructed in the short period of only six months.

This world of engineering was absorbed into

architecture by the early modernists at the beginning

of the 20th century. They were concerned with the

articulation of the functional spirit: FORM FOLLOWS

FUNCTION, and the honest expression of building

construction by freeing the hidden structure from its

imprisonment of the wall, by exposing it. A celebrated

example of this new philosophy of architecture is the

Villa Savoye by Le Corbusier.

Villa Savoye, 1929, Poissy-sur-Seine, France, Le Corbusier; the new aesthetics of modernism is

expressed by: (1) the pilotis or ground-level supporting columns, (2) the flat roof used as living

space, (3) the free plan made possible by elimination of bearing walls, (4) the freely designed

facade unrestrained by load-bearing considerations consisting of thin skin and windows

Maison Domino 1914 “domus” (house) and “domino” (suggesting serial production).

Maison Domino’s serially reproducible units introduce greater horizontal spatial freedom

(the free plan) achieved via pilotis (thin structural columns) and non-load-bearing walls

freely arranged as spatial dividers

Bauhaus 2, Dessau,

Germany, 1925, Walter

Gropius

The full integration of the spirit of structural engineering into architecture happened

during the 1950s and early 1960s or so, i.e. STRUCTURE IS ARCHITECTURE.

One group of architects even went so far to claim, ARCHITECTURE IS

STRUCTURE. It was the work of the pioneer design engineers Robert Maillart,

Eduardo Torroja and Pier Luigi Nervi that had a strong impact on the new

generation of architectural designers of the 1950s such as Eero Saarinen, Kenzo

Tange, Marcel Breuer, and many others.

The expression of structures during this era of the 1960s took many directions

ranging from the minimal and functional forms of Mies van der Rohe, Philip

Johnson, SOM (e.g. Bruce Graham/ Fazlur Khan, Myron Goldsmith), and I.M.

Pei, to the more sculptural forms of Paul Rudolph, Marcel Breuer, Kisho

Kurokawa, and Bertrand Goldberg.

During this period, the experimentation with structures, as started by the design

engineers of the 19th century, continued by adding the integration of complex

geometry and bionics (i.e. natural systems), especially as related to minimum

weight and surface structures which was brought to a high level of sophistication by

Frei Otto, Robert LeRicolais, Buckminster Fuller, Felix Candela, Heinz Isler, and

many others. This world of structural experimentation was convincingly represented

by the space frames, cable structures, prestressed membranes, and

pneumatics skins of the Expos in Montreal (1967) and Osaka (1970).

The experimentation with structures is also reflected by the constructivist art

of modernism and was first articulated particularly by the dreams of

designers such as the pioneers Antoine Pevsner and Naum Gabo at the

early part of the 20th century in Russia, and later by Alexander Calder's

kinetic art and Kenneth Snelson's tensegrity sculptures.

The early position of architecture as structure is very much reflected by the drawing of Mies van der Rohe's

52-story, 212-m IBM Tower in Chicago (1973) celebrates the frame and the geometrical order of the grid – the

building organization is controlled by the geometry of the 9 x 12 m bays (30 x 40 ft); the mathematical regularity of

the frame layout almost subdues the expression of its structural action. This regular frame layout is typical for

many buildings today because of its simplicity of construction

Lake Shore Drive Apts, Chicago, Ludwig Mies van der

Rohe, at Chicago, 1948 to 1951

This expression of minimal geometry, however, is surely not dated as expressed by the rational, neo-classicistic

Fuji Television Headquarters in Tokyo (1996) , designed by Kenzo Tange more recently. Here office and media

towers are connected by 100 m long sky corridors providing urban spaces and elements such as small plazas,

promenades, stair cases, bridges, and terraces at various levels. The mega-framework consists of

Vierendeel steel columns and beams with reinforced concrete that support a 32-m titan covered globe containing

a restaurant.

B. THE BIRTH OF UNIQUE STRUCTURES:

a period of transition

During the late 1960s and early 1970s or so, architects understood

the spirit of the engineering discipline and began to separate

themselves from the predominance of structural engineering

thinking. They had matured and developed the necessary courage to

invent their own structures by superimposing upon them other ideas

and meanings such as the effect of context, symbolism, possibly

fragmentation in geometry and material. In other words, during this

period, also sophisticated individual structures occurred in response

to particular situations quite in contrast to the catalogued structure

systems as identified by numerous types of line diagrams and rules

of thumb.

The 22-story, 100-m high,

BMW Building in Munich,

Germany (1972, Karl

Schwanzer) consists of four

suspended cylinders. Here,

four central prestressed

suspended huge concrete

hangers are supported by a

post - tensioned bracket cross

at the top that cantilevers

from the concrete core.

Secondary perimeter columns

are carried in tension or

compression by story-high

radial cantilevers at the

mechanical floor level. Cast

aluminum cladding is used as

skin.

BMW Building consists of four suspended

cylinders. Here, four central prestressed

suspended huge concrete hangers are

supported by a post - tensioned bracket

cross at the top that cantilevers from the

concrete core.

Secondary perimeter columns are carried

in tension or compression by story-high

radial cantilevers at the mechanical floor

level. Cast aluminum cladding is used as

skin.

C. A NEW GENERATION OF STRUCTURES:

the beginning

It was during the time of post-modernism of the late 1970s and early 1980s

when the progress of new structural thinking went unnoticed by most

architects in the USA and particularly in architectural education where

architectural theory began to flourish. The potential of those new

structures as space makers was not studied; the structures remained

hidden and solely used to do their job as support. In contrast, in Europe

the experimentation with structures continued by often brutally exposing

structures and expressing them in a rather animated fashion.

Citicorp Center (59 stories), New York,1977, Stubbins + William LeMessurier

An early example of this new type

of structure in the USA is the 59-

story, 279-m, 46 m square (152 ft)

Citicorp Building, New York (1977,

Stubbins), where the powerful

expression of structure

unfortunately is hidden behind the

post-modern skin. The renowned

structural engineer William J.

LeMessurier introduced a new way

of thinking about the building body

and structures with his spatial 8-

story series of chevron braced

stacks which act as 3-dimensional

units. This new breed of

megastructure looks so simple but

is so complex in behavior. Here,

the core acts as an interior vertical

beam with respect to wind within

the stacks.

In contrast in Europe, Richard Rogers, in

his love for technology exposes in the

Lloyd's of London (1978 - 86) the

functioning of the building body by

introducing a much freer and exuberantly

decorative treatment of the structure

recalling the 1960s plug-in cities of

Archigram. In the typical Rogers kit-of-

parts fashion, he broke the monotony of

the classic frame and expressed, a piece

of machinery with flexible kits, moving

parts, a network of ductwork and a

mechanically ventilated cavity façade (i.e.

3 layers of glass). He freely manipulated

the form of the concrete skeleton

structure by stepping it at various floor

levels and surrounding the braced

perimeter concrete frame by six

structurally independent satellite

service towers with permanent

maintenance cranes located on top of

them, while the internal perimeter columns

carry the elaborate 240-ft (about 73 m)

high central atrium structure crowned

by a barrel vault.

http://www.richardrogers.co.uk/render.aspx?siteID=1&navIDs=1,4,23,558&showImages=detail&showParent=true&sortBy=&sortDir=&imageID=1663

Pompidou Center, Paris, 1977, Piano and Rogers

Naturally, it all started with the 6-story

Pompidou Center in Paris (1977) by

Piano and Rogers, which introduces a new

generation of structures by exposing its

functional layers of structure assembly,

stairs, corridors, escalators and air ducts.

Its tension-braced hinged assembly

structure is quite opposite in spirit to the

conventional rigid monolithic

construction. The basic structure consists

of parallel 2.4 m (8-ft) deep Warren truss

beams that span c. 45 m (147 ft) across

the building to rest on small cantilever

beams called gerberettes, which are cast-

steel beams pin connected to interior

water-filled cast steel tubular columns and

tied down by exterior vertical tension rods.

For the first time cast steel was used to

articulate the joints

University Clinc (Klinikum), Aachen, Germany, 1981,

Weber + Brand

University Clinc (Klinikum), Aachen,

Germany, 1981, Weber + Brand

D. THE NEW LANGUAGE Of

STRUCTURES

A new language of structures may be characterized by the breakdown of

the building into smaller assemblies, by complex shapes and geometry, by

fractured forms as represented by fractal mathematics, by hinged

assemblies, multi-layered construction, forms in tension and compression

(i.e. buildings have muscles), mixed and hybrid structures, cast metals,

lightweight composite materials, complex spatial geometry, and so on.

There is even an indication that certain passive structures may be

replaced eventually by active structures with their own intelligence. We

are already quite familiar with smart materials and energy dissipation

systems. Computers and advanced technology give us answers that we

will have to face, if we like it or not.

In the following discussion of cases, structures may take more or less three positions:

• The complex hidden structure derived from intricate geometry and not from

the nature of the support structure; a convincing example is the Guggenheim

Museum in Bilbao, Spain, by Frank Gehry (1997). In other situations computers

find the optimum layout of structures within given boundaries

• The structure as the primary idea of architecture, but not necessarily derived

from traditional engineering thinking of optimization or tectonic expression, but

other intentions: architects invent structures - subjectivity and creativity are

introduced in spite of the limits imposed by the rules and physical laws of

engineering.

• The dialogue (or play) of architecture with structure, or symbolism with

tectonics, on a more local scale, possibly as a leitmotif: architecture as

structure detail.

I will present some of those characteristics by addressing the following six topics:

• the large scale of the high-rise building

• the smaller and more human scale of lower buildings

• the effect of the building section, or columns as space makers

• achieving the long span through arches and the corresponding

effect on space

• the transparency of the glass-skin structures

• the conclusion, a new dimension of structure

THE LARGE SCALE:

high-rise buildings

First I will be showing several high-rise buildings of this new generation that

are broken up, hollowed out, lifted up, subdivided into smaller buildings, placed

on top of each other, or by using mega-structures. An early example of this

free manipulation of material space is,

the 21-story bridge-like concrete structure of

the Hypobank in Munich, Germany (1981,

Walter and Bea Betz), where the structural

concept demonstrates another kind of a new

generation of structures. Its shape reminds

one of the metabolist architecture of the

1960s in Japan although somewhat softened

by less articulation of tectonics and through

the use of the skin and the lightness of the

triangular prisms. Here, four cylindrical

towers with a story high platform at the 11th

service level (that consists of three rigidly

connected prestressed box-like girders) form

an irregular spatial rigid megaframe. This

structure supports 15 stories above and the

hanging 6 stories below.

The 43-story, c. 200-m high, Hongkong Bank

in Hong Kong (1985, Foster/Arup) is an ikon of the

1980s - it is a celebration of technology and

architecture of science as well of function as art. It

expresses the performance of the building and the

movement of people. The stacked bridge-like

structure allows opening up of the central space

with vertically stacked atria and diagonal

escalator bridges by placing structural towers with

elevators and mechanical modules along the sides

of the building. This approach is quite opposite to

the central core idea of conventional high-rise

buildings. The support structure is clearly expressed

by the clusters of eight towers forming four parallel

megaframes. A megaframe consists of two

towers connected by cantilever suspension

trusses supporting the vertical hangers which,

in turn, carry the floor beams. Obviously, it was

not the intention for the structure to articulate

structural efficiency.

Hiroshi Hara, the architect of the Umeda Sky

City, Osaka (1993) called the building with

the urban roof and floating gardens, city in

the air. The building expresses postmodern

sensibilities, challenging the unity of form by

articulating diversity. The 40-story, 173 m

high double-tower (54 m apart) is connected

by a huge 2-story 54-m span roof bridge

structure with a large circular sky

window. This square platform- bridge (150

m above the ground) provides urban space

and gardens in the air. The human scale is

reinforced by a pair of almost floating

escalators, free-standing transparent

elevator shafts and staircases, as well as a

6-m wide steel sky bridge that links the

buildings at the 22 level.

Although the building required advanced

structural engineering especially in

earthquake country, Hara did not express the

effort of the support structure; he softened

structural engineering by the finish of

reflective glass, polished aluminum plates,

undulating surfaces, etc.

The 19-story City Gate in Duesseldorf , Germany

(1998, H. Petzinka + Fink Arch./Ove Arup preliminary

design of structure) consists of 80 m towers with the

top three floors connected. The space between

forms a 58 m (184 ft) tall atrium with suspended

glass curtain facades enclosing the enormous

volume. The twisted composition of the rhombus-

like arched building adds a daring futuristic

image to the city skyline. Exposed are the two

triangular trussed framed core towers, which clearly

give lateral support to the building. These mega-

columns are connected to form three portal

frames that is a Z-like bracing system in plan

view; they seem to tie the vertical open atrium space

visually together. The support of the mega columns

is suggested to the outside through the transparent

glass skin. The steel pipes of the trussed frames are

filled with concrete. Not only the futuristic space

atmosphere (which includes air bridges at various

levels), but also the highly energy efficient design

must be recognized.

The Commerzbank in Frankfurt, Germany,

(1997, Norman Foster/Arup) is with nearly 300

m height the tallest office building in Europe. It is

the world's first ecological (green) high-rise

tower , energy efficient and user friendly. In

other words, the goal was an environmentally

friendly architecture that is living in harmony

with nature and the integration of innovative

concepts of energy conservation. Four-story

gardens spiral around the gently curved

triangular plan with a central atrium serving as a

natural ventilation chimney. In other words,

fresh air penetrates the central vertical atrium

through the winter gardens to provide natural

ventilation. The building structure consists of

the vertical cores at each of the corners of

the triangular plan linked and braced along

the perimeter by staggered 8-story

Vierendeel frames, which in turn, bridge the

4-story open garden spaces at various levels

that are connected to the central atrium

shaft. The steel /concrete structure acts as a

perforated tube providing the necessary lateral

and torsional stability.

In contrast, the monumental Tokyo City

Hall (1991) by Kenzo Tange is designed

in the postmodern style reminding us of

French cathedrals composed with

computer chips. The double-tower

structure, a 48-story, 243-m high

building consists of 6.4-m

supercolumns (i.e. shafts) forming a

megaframe. The supercolumn is made

up of four 1.02-m steel box columns

linked by K-braces. The megacolumns

are interconnected by 1-story deep

belt trusses at the 9th, 33rd, and 44th

floors. Column-free space is allowed

between the super- columns using two-

way beam grids

In contrast, the 18-story, 87-m high N.V. Nederlandse Gasunie in Groningen, 1994, Alberts and Van Huut

bv, is more organically shaped. It seems to be the skin, which is constantly in movement under the change

of sun and weather. The slender tall building (1:6.69) consists of load bearing concrete walls anchored

front to back by two nearly 0.5 m thick (20-in.) diaphragm cross walls. The central foyer is spanned by a

3-story, 2-legged A-frame which carries the central column around which the concrete stair case

seems to be suspended and spirals upward thereby articulating the dynamics of space. This

complicated, 3-dimensional structure forms the central vertical backbone of the building body. The 60-m

glass wall in front appears almost like a waterfall; it is carried by an enormous steel space frame.

THE HUMAN SCALE:

low-rise buildings

The next group of buildings represents smaller scale structures

articulating similar concepts as before, such as: expressing the assembly

character together with lateral bracing, or freedom of form giving from

traditional construction, possibly resulting in irrational organization of

materials and spaces

The Kandel apartment building, Heidenheim,

Germany, 1997, Hoefler Arch., appears like

several buildings on top of each other, each one

with its own support structure. In other words,

the building mass is broken up into different

structures. Notice the red column running

diagonally all the way up to the roof relaxing the

hierarchy of the support structure.

The Information Box is a temporary structure at the Potsdamer Platz in Berlin,

Germany, 1995 - 2001, (Schneider + Schumacher), it looks like a container sitting

on a forest of columns. The container floats high above the ground and sits on the

inclined exposed steel columns suggesting the building support. The window areas

indicate large open inside spaces.

The dramatic building massing of the Hamburg Ferry and Cruise Ship Terminal (1994, William Alsop/ Ove

Arup) reminds one of shipbuilding construction. The upper building portion and the balcony at the building end

are supported by inclined pylons and tie rods reminiscent of the cranes and derricks along the quay side.

Frank O. Gehry's, three building complex (one is clad in metal, one in plaster, one in brick), Neuer Zollhof

(1998) in Duesseldorf, Germany, looks like an unstable collage. The walls of the center building have a

surface whose shape is much like that of folds of hanging fabric, where the undulating wall is clad in

polished stainless steel. It is an example of how computers are required to deal with the complexity of form

in designing and building a structure. The architect used the design software Catia to model the distorted

and twisted façade walls with window boxes sticking out, which are identical for all three buildings. In

contrast to Gehry's Guggenheim Museum in Bilbao where the complex surfaces were formed by

skeletons, which were skinned, in the Neuer Zollhof they were solid concrete walls for the middle portion of

the building group (but for the 13-story tower concrete frame construction with fill-in masonry walls was

used). The walls were constructed from prefab panels (i.e. first Styroform molds, then steel reinforcing and

finally concrete) all different from each other using Computer Aided Manufacturing (CAM). In other words,

the construction of the houses was approached similar to the production of car bodies or airplane wings.

In the Saibu Gas

Museum (1989) in

Fukuoka, Japan, by

Shoei Yoh, 4 floors are

suspended from column

shafts from within the

building to liberate the

ground floor from

columns. The

design with its central

trees articulates an

almost poetic expression

of industrial technology

The School of Architecture at Lyons, France

(1989, Jourda and Perraudin) incorporates a

variety of structural forms and materials

including arches, trabeation, cross-vaulting

bearing walls, glass skins, and fabric

membranes. The idea of the architecture is

derived from the education of architects. It

introduces a vocabulary of materials, details,

and construction systems. The building

consists of a massive concrete base, an

open 2nd floor studio space covered with a

timber framed vaulted structure (i.e. inclined

radiating glulam timber struts rising to the

roof), a central spine covered with a light-

weight glass structure and cable trusses, and

along the outside a fabric membrane to

provide shade. At the junction of the glulam

wood members castings are used to articulate

the joining between beams and columns.

Nick Grimshaw clearly expresses the structure of the Sainsbury Supermarket Camden Town, London (1988).

The main parallel 40-m span frames consist of slightly arched roof trusses suspended from tapered cantilever

steel girders, where the flat profiles preclude the benefit from arch action. These girders form the long interior

arms of asymmetrical double cantilever beams supported on concrete-filled stunchions, while the short

arms project outside beyond the wall cladding where the arches are tied down by back-stays that consist of four

50 mm vertical tension rods.

In contrast, the main structure for the Wilkhahn Factory, Bad Muender, Germany, 1992, by Thomas Herzog

Arch., is parallel to the façade (i.e. longitudinal); the building integrates function, construction, ecological

concern and architecture. The 5.4 m wide (18 ft) tower structures that contain the offices and service zones,

are centered at 30 m (98 ft) and give support to the long spans of the cable-supported beams (24.6 m/81 ft).

The formal configuration of the cables (1.5 m deep) convincingly reflects the moment flow of

continuous beams under gravity load action. The diagonal bracing of the towers gives lateral support to the

post-beam timber structure to resist wind with a minimum effort.

Of exact opposite character is the Vitra Museum, Weil am Rhein, Germany, 1989,

Frank O. Gehry: complex building bodies and irrational arrangement of shapes

together with distorted geometry and construction cause an exciting space

interaction.

In the Palais du Cinema (former American

Center in Paris, 1994) Frank Gehry expresses

the explosive nature of form and complex

geometry, he articulates volumes that seem to

tumble out. The inside of the building is as

resolved and eroded as the outside (inverse of

the outside) almost like medieval urban spaces.

The intersection of stairs, corridors, openings,

intersecting planes, cause a very dynamic

explosive inside space. The complex geometry

requires complex hidden structures.

The Hysolar Institute at the University of Stuttgart, Germany (1988, G. Behnish and Frank Stepper) reflects

the spirit of deconstruction, it looks like a picture puzzle of a building - it is a playful open style of building

with modern light materials. It reflects a play of irregular spaces like a collage using oblique angles causing

the structure to look for order. The building consists of two rows of prefabricated stacked metal

containers arranged in some haphazard twisted fashion, together with a structural framework

enclosed with sun collectors. The interior space is open at the ends and covered by a sloped roof

structure. The bent linear element gives the illusion of an arch with unimportant almost ugly

anchorage to the ground.

THE COLUMN AS SPACE MAKER

The next group of slides addresses the COLUMN as space makers, or

demonstrates the effect of the building SECTION as a controlling design determinant

rather than solely considering the DOGMA OF THE PLAN. Column types include slender and

stocky ones, compression and tensile columns, straight and inclined or branched columns, but

they all are space makers.

The Netherlands Architectural

Institute in Rotterdam (1993, Jo

Coenen) is clearly divided into several

sections. The concrete skeleton

dominates the image supplemented by

steel and glass. The main glazed

structure appears to be suspended, and

allows the concrete load-bearing

structure behind to be seen. The high,

free-standing support pillars and the

wide-cantilevered roof appear more in a

symbolic manner rather as support

systems.

Art Museum, Wolfsburg, Germany, 1993, Peter

Schweger Arch.: the building floats intospace.

The building is laid out on an approximately 8.10 x

8.10 m (27 x 27 ft) grid and is further subdivided

into 1.35 m (4'5" ) square bays. The plaza seems

to reach/move into the building - the building is

naturally grown allowing the interaction of building

and urban space, where the diagonal access

ramps/stairs forming the connecting element (i.e.

entrance at building corner). The interaction of

the building is especially articulated by the

thin cantilevering roof at 19 m (62 ft) height

carried by the slender columns. The building

gives a feeling of openness and and permeability.

The logic of construction, transparency, lightness,

quality of detail all transmit a sense of clarity (i.e.

no deliberate confusion as in some of the other

cases).

Axel Schultes, the architect for the City

Museum, Bonn, Germany (1992) calls the

building the house of light. The curved flat roof

sits on a forest of irregularly arranged columns.

The grouped columns seem almost to generate

a human quality in articulating space rather than

supporting the roof, the columns seem to

penetrate through the roof.

The 300-m long oval-shaped Grand Palais, Lille (1995, Rem Koolhaas/ Ove Arup

for structures), is divided into concert hall, conference center, and exhibition halls.

Koolhaas uses exposed concrete surfaces and a great deal of plywood and plastic

to reduce the costs. The combination of unusual materials and unexpected angles

seem to reflect an anti-poetic mood (a punk-like aesthetics) and redundancy of

structure. The structure takes the place of language and reflects only the illusion

of support (e.g. arch vs. columns, and hanging columns or tension ties to reduce

bending moment at center span). Notice the stairs as an important architectural

element.

For the multi-bay structure of the shopping center near Nantes, France (1988, Rogers/Rice) 94-ft (29 m)

high tubular masts, spaced at 47 ft (14 m), support the roof framework in a spatial fashion from above

without penetration of the roof. Only certain combinations of the 3-dimensional network of rods and struts

are activated under various load actions. Under wind uplift, the tensile rod-strut system forms an inverted V-

shaped truss.

An example of Rogers’ first stayed structures is the Patscenter in Princeton, USA (1984, Rogers/Rice).

The building consists of parallel planar guyed structures along the central spine consisting of c.9 m wide

portal frames set 11 m on center that support on top c.15-m high A-frames which consist of inclined

pipe columns connected to a large ring plate from which are suspended steel rods to other ring plates on

each side of the spine. Inverted truss action is required for wind uplift where the central hangers act in

compression, hence had to be tubes.

The immense, c.153-m span roof of the beautiful Lufthansa Hangar at the Munich Airport, Guenter Buechl + Fred

Angerer Arch., 1992, is supported by the diagonal cables suspended from the c.56-m tall concrete pylons

The Renault Center, Swindon, U.K. (1983) by Norman Foster and Ove Arup is a spatially guyed structure.

Truss-like portal frames are placed along the 24 x 24m (79-x79-ft) square bays, but also along the diagonal

directions. Rods are suspended from the top of the 16-m (53-ft) high tubular steel masts in the orthogonal and

diagonal directions to support the tapered portal beams at their quarter points. In the center portion the sloped

beams are cable-supported from below. The cable configuration follows the moment diagram of a

multibay portal frame with hinged basis under uniform gravity loading by efficiently resolving the moment

into compressive and tensile forces. The slender tubular columns are laterally braced with four prestressed

rods that are connected to their sloped beams thereby providing a moment connection.

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Whereas before, the cables supported a rigid cylindrical roof structure, in the Schlumberger Research

Center, Cambridge, UK (1985, Hopkins/Hunt) it is a spatial domelike undulating tensile fabric

membrane. The ship like masts and rigging as well as its high level technology and detailing reminds

one of Roger's earlier work. The central portion of the building is subdivided by four parallel exposed

portal steel frames into three bays, each 24 x 18 m (79 x 59 ft) in size. It consists of horizontal 24-m (79-

ft) open triangulated truss girders and nearly 8-ft (c.2.5 m) wide vertical trusses which support two pairs

of upper and lower booms. The two inclined upper tubular masts are supported by tie rods, which are

braced by lower masts (struts). Cables are suspended from the masts to give support to two parallel ridge

cables at certain pick-up points. The translucent Teflon coated fiberglass membrane is clamped and

stretched between ridge cables and steel work.

Quite different in spirit are the slender

and minimal abstract planar, tree-like

c.30-m (100-ft) high masts for the Horst

Korber Sports Center in Berlin,

Germany (1990, Christoph Langhof) with

their five branches linked by cables from

which the light cable roof trusses are

hung but only on one side (i.e.

asymmetry). The symmetrical abstract

forms of the masts are completely

opposite in expression from the tectonic

shapes of most of the other examples

which have been shown, they don't

seem to give support.

The huge steel trees of the Stuttgart Airport Terminal, Stuttgart, Germany (1991, von

Gerkan & Marg, Schlaich) with their spatial strut work of slender branches give a continuous

arched support to the roof structure thereby eliminating the separation between column

and slab. The tree columns put tension on the roof plate and compression in the branches;

they are spaced on a grid of about 21 x 32 m (70 x 106 ft).

a.

b. c.

THE TECTONICS OF CONSTRUCTION

The tectonic organic world of structural resistance has become quite

fashionable especially with the architect/engineer Santiago Calatrava. He

is fascinated with how the structure works and how the loads are carried to

the ground, which he demonstrates by articulating its tactile quality and the

organic nature of the skeleton comprised of sculptural, bony-shaped

elements asymmetrically arranged. He is concerned with the logic of

material and the beauty of the section, he emphasizes the dynamics of

structure by making the potential movement of forces visible. He

achieves that by expressing the unbalance of forces.

The supporting cantilever frames of the glazed canopy

structure of the Stadelhofen Station, Zurich,

Switzerland (1990, Santiago Calatrava) capture

movement. The columns seem to be just caught in

time by the vertical struts. In other words, it seems as if

the cantilevers are on the verge of rotating by

articulating the hinge like tubular beam and by letting

the slanted columns be just caught on time by the

vertical struts. They are surely influenced by biological

forms where the steel profile of the tapering members

suggests a tectonic presence, frozen suspension and

almost organic joints. The sword-like steel plates of the

cantilever beams carry the glass roof and are welded to

a continuous 12 cm (5 in.) dia. steel tube that acts as a

beam and torsion ring to transfer the loads to the

inclined, branching Y-columns of triangular cross-

section which, in turn, are stabilized by vertical hinged

pendulum columns. The 2-legged composite columns

are spaced at almost 6 m (20 ft).

The Public Library in Munster, Germany (1993, Bolles + Wilson) is divided into two sections

connected by a bridge. The asymmetrical, inverse A-frame not only carries the sculptured roof

structure but also provides a vigorous energy and dynamics to the urban space.

The grandstand of the Charlety

Stadium at the Cite Universitaire in

Paris (1994, Henri and Bruno Gaudin)

is brought alive by its organic and

tectonic presence. From the highly

articulated slanted concrete

buttress piers is cantilevered the

stayed steel canopy on top and the

upper seating below. The play

between tension and compression,

between force resolution at the joints

and stress concentrations in the

members is forcefully articulated.

From the inclined, 50-m high corner

light masts at the lower level a

conical Teflon membrane is

suspended to give lateral

protection to the grandstand.

SPANNING SPACES WITH ARCHES

This collage type visual study introduces the next theme that of the structure

as span, in this case achieved through the A R C H; it attempts to articulate

the spirit of the support structure resisting lateral thrust, in other words the

tectonics of construction.

This collage type visual study introduces the

next theme that of the structure as span, in

this case achieved through the arch; it

attempts to articulate the spirit of the support

structure resisting lateral thrust, in other

words the tectonics of construction.

The lateral thrust

The curved roof of the Kansai Air Terminal (1994) by Renzo Piano (and Peter Rice

for structures) spreads over an artificial island like a glider. The irregular roof curve

consisting of arcs of different radii, is shaped by the aerodynamics of the large-

scale air jets ventilating the whole space, that is the regulation of air

movement. The three-dimensional, triangular truss-arches span 83 m and have a

total length of 150 m each is supported by inclining columns and by vertical columns

at the curb; the arches seem barely connected the building.

The column supports at the Novotel Belfort, Belfort, France (1994, Bouchez),

almost seem human and express how effortless the arch action is transferred down

to the ground.

The visually dominant arches of the new Leipzig Fair, Leipzig, Germany, 1996, (van

Gerkan+Marg Arch, Ian Ritchie Arch. for glazing, Polonyi Struct. Eng.), make a strong

statement and remind one of the glass and iron architecture of the 19th century (e.g. Crystal

Palace, Galerie des Machines in Paris, 1889). The hall is about 243 m long, has a clear span

of 80 m (262 ft), and 30 m (98 ft) up to the vertex. The primary system consists of the

trussed triangular arches that contain a service walkway, and where the top chords span

across the adjacent service roads. The sole purpose of the arches is to give lateral support to

the tubular steel grid vault through its steel outriggers. The depth of the arches varies from 4

m at the crown to 10 m at the ground. The steel grid vault is formed by 3.125 x 3.125 m

(appr.10 x 10 ft) cells, from which is suspended by frog fingers the glass vault beneath. The

glass panes are approximately 3.1 x 1.5 m and are joined with silicone. It is the largest

suspended glass shell in existence today.

Oguni Glass Station, Kumamoto Pref., 1993, Shoi Yoh Arch., is a small gas and service

station covered with a unique glass canopy suspended from arched concrete frames. The

thin glass membrane of glass plates with an inlayed layer of perforated aluminum sheet

comes alive with sparkling brilliance when the sun shines through it.

The 100-m span tied arch Japan Bridge in Paris (1993, Kisho Kurokawa) consists of the two

main inward leaning tubular steel arches, the walkway of triangular precast concrete panels

covered by a curved glass enclosure, and the support of the arched spatial cable-strut

network. The walkway and glass enclosure are suspended from the arches. The lateral arch

thrust is taken by the cable-strut network at the base. Torsion due to lateral loads is efficiently

resisted by the triangular cross-section of the bridge (i.e. torsion box).

Kempinski Hotel, Munich,

Germany, 1997, H. Jahn/Schlaich:

the elegance and lightness of the the

40-m (135-ft) span glass and steel

lattice roof is articulated through the

transparency of roof skin and the

almost non-existence of the diagonal

arches which are cable- supported

by a single post at their

intersection at center span. This

new technology features construction

with its own aesthetics reflecting a

play between artistic, architectural

mathematical, and engineering

worlds. The depth of the box arches

is reduced by the central

compression strut (flying column)

carried by the suspended tension

rods. The arches, in turn, are

supported by tubular trusses on each

side, which separate the roof from

the buildings.

The Munich Airport Business Center, Munich, Germany, 1997, Helmut Jahn Arch.

Ove Arup Eng.: also is an open public atrium as transition between building blocks or

walled boundaries to form a square which is covered by 6 arch-supported membrane

leaves. In other words, a transparent roof is carried by spatial triangular column

frames. Here a minimum of structure gives a strong identity to space.

The Satolas Airport TGV Train Station, Lyons, France (1995, Santiago Calatrava) consists of the big entrance

hall and the long naves. The 40 m high (131-ft), 100 m wide, 120 m long entrance hall appears like a huge

sculpture reminding us of a bird or butterfly that has a triangular plan with asymmetrical cantilevers. Here, the

central spine is a 90-m (295-ft) span 3-dimensional arched torsion ring steel truss with a variable triangular

cross-section where the two tubular bottom chord arches are anchored in immense single-fluted concrete

thrust blocks or buttresses (one in front and two at the buildings rear) that look like animated. Steel ribs

laterally brace the huge curtain wall box columns, which also carry most of the cantilever wing weight. The

columns, in turn, rest on massive concrete arches on each side, which carry most of the building weight. The

bird consist of 1300 tons of steel resting on the two concrete arches. The heavy closely set black steel

members seem over structured because of the density of the layout. The oversized members obscure the

relationship between the structure of the roof and the support of the glazing.

The long naves over the 3-bay track level are covered by 53-m (174-ft) wide lamella vaults of slender ribs

on a c. 9-m (30-ft) structural bay. Each of the three vault segments rests on the apex of two triangular

concrete supports (i.e. the side walls are rows of multi-faceted V- shaped concrete columns). The middle

tracks are for through trains that move over 300 km/h requiring careful calculations of shock waves. The

thrust of the vault at the middle segment is released by the box at the core, i.e. the triangular supports at the

middle part of the vault are tied together at lower level creating an enclosed box tunnel at the core of the

station.

The lattice like barrel vaults can also be visualized as diagonally intersecting two-way arches, or almost

like a triangular folded plate membrane with a maximum of material removed, leaving only folds. The roof

panels are either glazed (clear), opaque (concrete panels) or left open, creating defused light and mystical

spatial qualities. The wings are clad in reflected aluminum. The long naves represent a spectacular vaulted

space, airy, translucent, with an effortless organic fluidity and lightness.

How opposite in spirit is the delicate roof structure of the Lille Euro Station, Lille,

France (1994, Jean-Marie Duthilleul/ Peter Rice) consists of two asymmetrical

transverse slender tubular steel arches (27 cm or 10.75-in dia., set at about 12 m

or 40 ft on center) braced against buckling by deceitfully disorganized ties and

rods; this graceful and light structure, in harmony with the intimate space, was not

supposed to look right. A series of slender tubes are supported on arches which, in

turn, carry the approximately 1.8 m (6-ft) deep longitudinal cable trusses that

support the undulating metal roof. The support structure allowed the gently curved

roof almost to float or to free it from its support, emphasizing the quality of light.

GLASS STRUCTURES

The next topic addresses briefly glass-skin structures, or glass as a structural

material, where many of them are tension supported. Here the tensile glazing

support structure becomes part of the glass skin; the traditional nonstructural

members of glass and sash become structural. Special, non-conventional details

are used as based on forging, casting, and machining steel. The glass weight is

transferred across star-shaped (e.g. H-, or X-shaped) castings to vertical

tension rods or each panel is hung directly from the next panel above.

Vertical or horizontal cable-truss systems give lateral support to the glass

wall. The glass panels are glued together with silicone, which makes them

quite rigid so that racking movement is allowed in the sliding of the bolt

connections to the star-shaped castings. Some typical examples are:

Shopping Center, Dalian, China

Xinghai Square shopping mall, Dalian

Museum of Science and Technology, Parc de

la Villette, Paris (1986), Fainsilber/Rice).

three monumental greenhouses equivalent

to a 10-story building that are attached to

the south side of the museum

The development of suspended glass skins has

been significantly influenced by the glass walls for

the three monumental greenhouses equivalent to a

10-story building that are attached to the south side

of the Museum of Science and Technology, Parc

de la Villette, Paris (1986, Fainsilber/Rice). The

tower like structures are about 32 m wide by 32 m

high and 15 m deep. They capture and store heat

for the museum. The glass wall is subdivided into 16

approximately 8-m square (27-ft) modules, which

form the basis for the primary stainless steel tubular

frame which is laterally supported against wind by

cable trusses. Each of the 8-m (27-ft) square

modules consists of sixteen 2-m square glass

sheets laterally supported by a secondary system of

horizontal cable beams (tension mullions), which are

stabilized by the glass. The glass panels are

suspended from the main frame. They are

attached to each other with clear silicone sealant

and are joined at the corners by a molded steel fixing

that allows movement and reduces stress

concentrations. The glass weight is transferred in

tension from the lower to the upper panels and is

hung from the main frame beam by prestressed

spring devices that act as shock absorbers and

allow readjustment in case of unusual loading.

The composition and materials of the massive skeletal support structure for the glass houses in the Parc Andre-

Citroen, Paris (1992, Patrick Berger/ Peter Rice) remind one of the past in contrast to the language of the minimal

glass walls. The 15-m high portal frames are cladded in wood and stone (spaced at 15 m) and are connected by

edge beams at the roof level. The glass walls seem to be independent of the internal support structure and are

suspended from the top edge beam by spring connections as in the Museum of Science, La Villette. The

connections act as solid support under normal loads but as shock absorbers under shock (over) loads to prevent

accidental damage to the glass. The glass walls are laterally supported by the primary vertical cable trusses

adjacent to the steel columns (which also provide the connection to the building skeleton) and the secondary

horizontal lens-shaped cable beams with a central spine compression member that resists the tension in the

cables. Vertical cables resist the buckling of the horizontal trusses vertically..

An extraordinary complex spatial steel

framework supports the glass skin of

the 22-m (71-ft) high, 35 x 35 m (115 x

115 ft) Pyramid at the Louvre in Paris

(1989, I.M. Pei/ Roger Nicolet). Here,

stainless steel bowstring trusses form

a two-way diagrid structure on each

plane of the structure. In other words,

sixteen crossed beams of different

lengths are placed parallel to the

diagonal edges. By extending the truss

struts, the aluminum mullion frame is

supported. To prevent the outward

thrust of the pyramid and to stabilize

and stiffen the shape, the four faces are

tied together by 16 horizontal counter

cables (i.e. belts) in a third layer

thereby bracing and stressing the

diamond-shape network. In their search

for visual lightness the designers

developed a difficult layout of structure,

which reflects a celebration of structural

complexity and still achieving the goal of

transparency and an almost immaterial

lightness with its thin member fabric.

NEW DIMENSIONS OF STRUCTURES

As conclusion I like to present three cases that represent truly the new dimension of structures.

With the elliptical glass atrium hall of the Tokyo International Forum, (1997), Rafael Vinoly

together with the structural engineer Kunio Watanabe express true structural originality. The

unique 208-m long roof structure that is about 31.7 m wide, resembles an exposed ship hall

or prehistoric structure which floats 60 m above the ground and together with the suspended

lightweight ramps and bridges reflects an almost medieval cathedral like impression.

The main span of the roof structure which is about of 12-m depth at mid-span, consists of a pair of 1.2- m φ

tubular inclined steel arches that span 124 m between the columns and curve up in half-arches in the

cantilever portion. A series of 16 tension rods inversely curved to the compression arches complete the

beam action. The layout of the compression arches and tension rods that follow directly the bending

moment diagram under gravity load action of a beam with double cantilevers, are separated by 56

curved steel arch-ribs which also support the roof beams. The glass walls are supported laterally by 2.6-m

deep free-standing vertical cable trusses which also act as tie-downs for the spatial roof truss.

The parabolic spatial roof arch

structure with its 42-m cantilevers

is supported on only two

monumental conical concrete-filled

steel pipe columns spaced at 124

m. The columns taper from a

maximum width of 4.5 m at roughly

2/3 of their height to 1.3 m at their

bases and capitals, and they are

tied at the 4th and 7th floors into

the structure for reasons of lateral

stability.

As impressive, possibly more heroic is the TGV Station,

Paris-Roissy (1994, Paul Andreu/ Peter Rice). Here, the roof

is freed (separated) from the structural support, it seems to

float above the walls - they never touch. It consists of

parallel crescent-shaped transverse trusses (48 m or 156-

ft span, 4 to 7 m or 13 to 23 ft deep) of triangular cross-

section. The two 36 cm or 14-in. dia. bottom chords form an

arched ladder where the members merge at the ends (i.e.

lens-shape) and are connected by the diagonal ties and

slender vertical tubular web members to the horizontal solid

rods of the top chord which are prestressed to keep them in

tension. The trusses are hanging at the top chords near

the center-span from asymmetrical tree columns on

concrete pylons in the longitudinal direction. The truss

ends are pulled down by prestressed vertical tension

rods to control truss movement. The concrete pylons are

located between the trusses so that the bottom chords seem

unsupported. A further confusion is caused by the heavy

suspended arch and the thin horizontal tie, which

should be the other way around according to

conventional thinking, but the truss is not simply

supported at the ends as the form suggests. The main

trusses support longitudinal triangular steel trusses which, in

turn, carry the orthogonal steel grillage with glass panels.

The glass wall is laterally

supported by vertical

tubular cantilever masts

with cantilever arms and

are spaced at 4.75 m; the

glass panels are hung

from the cantilever arms.

The masts are as much as

17 m high and are braced

by pretensioned cables

against twisting. The

building column grid is

offset from the trusses

and vertical tension rods

to avoid the impression

that the roof is hanging or

the masts carry the roof.

I like to conclude my presentation with La Grande

Arche, Paris (1989, Johan Otto von Sprechelsen/

Peter Rice for the canopy) where the architecture

masterfully interweaves the spontaneity of the

moment and technology as reflected by the

tensile roof and elevator tower, with the

symbolism of the giant arch, a modern version

of the Arc de Triomph.

La Grande Arche is a giant nearly 110 m hollow

cube. The 35-story side buildings are bridged by 3-

story frame beams at the top. The primary structure

of each of the about 18-m wide side buildings

consists of four post-tensioned concrete mega-

frames tied together every seven floors and

stabilized by diagonal walls at the corners thereby

forming nearly 21 meter squares in elevation. The

frames and walls rest on neoprene cushions, the

only movement joints, on top of huge caissons.

The floating, tensile textile membrane over

the base reflects the lightness and

spontaneity of the cloud and contrasts the

perfect geometry of the giant cube thereby

introducing a human scale besides providing

shelter and improving wind conditions. The

complex cloud structure consists of

diagonally cross-braced parallel lens-

shaped cable beams prestressed against

free-form edge cables. The translucent fabric

membrane is stressed against the underside

of the cable beams and also supported by

small flying struts at the center of the meshes.

The composite prestressed structure is

suspended from the walls of the cube.

The free-standing nearly 92-m (300-ft) high

cable-braced steel lattice elevator tower is

anchored laterally to the building with

horizontal guyed columns.

The architecture clearly demonstrates that there can be

harmony between the preservation of the past and the

inventions of the present, and that they do not necessarily

represent opposite positions.