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PROF. WOLFGANG SCHUELLER
Building structures are defined by geometry, materials, load
action, and construction as well as form, that
is, its abstract dimensions as taken into account by
architecture. When a building has meaning by
expressing an idea or by being a special kind of place, it is
called architecture. Although structure is a
necessary part of a building, it is not a necessary part of
architecture; without structure, there is no
building, but depending on the design philosophy, architecture
as an idea does not require structure.
The relationship of structure to architecture or the
interdependence of architectural form and structures is
most critical for the broader understanding of structure and
design of buildings in general. On the one hand,
the support structure may be exposed to be part of architecture.
On the other hand, the structure may be
hidden by being disregarded in the form-giving process, as is
often the case in postmodern buildings.
One may distinguish structure from its visual expression as:
hidden structure vs. exposed structure vs. partially exposed
structure decorative structure vs. tectonic structure vs.
sculptural structure innovative structures vs. standard
construction
The purpose of structure in buildings may be fourfold: Support.
The structure must be stable and strong enough (i.e., provide
necessary strength) to hold
the building up under any type of load action, so it does not
collapse either on a local or global scale (e.g., due to buckling,
instability, yielding, fracture, etc.). Structure makes the
building and spaces within the building possible; it gives support
to the material, and therefore is necessary.
Serviceability. The structure must be durable, and stiff enough
to control the functional performance, such as: excessive
deflections, vibrations and drift, as well as long-term
deflections, expansion and contraction, etc.
Ordering system. The structure functions as a spatial and
dimensional organizer besides identifying assembly or construction
systems.
Form giver. The structure defines the spatial configuration,
reflects other meanings and is part of aesthetics, i.e. aesthetics
as a branch of philosophy.
There is no limit to the geometrical basis of buildings as is
suggested in the slide about the visual study of
geometric patterns.
The theme of this presentation brings immediately to mind the
spanning of bridges, stadiums, and other
large open-volume spaces. However, I am not concerned only with
the more acrobatic dimension of the
large scale of spanning space, which is of primary concern to
the structural engineer, but also the
dynamics of the intimate scale of the smaller span and smaller
spaces.
The clear definition of the transition from short span, to
medium span, to long span from the engineer's point of view, is not
always that simple.
Long-span floor structures in high-rise buildings may be already
be considered at 60 ft (c. 18 m) whereas the
long span of horizontal roof structures may start at 100 ft (c.
30 m). From a material point of view it is apparent that the long
span of wood beams because of lower
strength and stiffness of the material is by far less than for
prestressed concrete or steel beams.
SPANNING SPACE HORIZONTAL -SPAN BUILDING
STRUCTURES
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Scale range:
Long-span stadium: e.g. Odate-wood dome, Odate, Japan, 1992,
Toyo Ito/Takenaka, 178 m on oval plan
Atrium structure: e.g. San Franciscos War Memorial Opera House,
long-span structure behavior investigation
High-rise floor framing: e.g. Tower, steel/concrete frame, using
Etabs Parthenon, Athens, 430 BC
The Development of Long-span Structures:
The great domes of the past together with cylindrical barrel
vaults and the intersection of vaults represent
the long-span structures of the past. The Gothic churches
employed arch-like cloister and groin vaults,
where the pointed arches represent a good approximation of the
funicular shape for a uniformly
distributed load and a point load at mid-span. Flat arches were
used for Renaissance bridges in Italy.
Example of short span: Parthenon, 430 BC, Athens
The development of the wide-span structure
The Romans had achieved immense spans of 90 ft (27 m) and more
with their vaults and as so powerfully demonstrated by the 143-ft
(44 m) span of the Pantheon in Rome (c. 123 AD), which
was unequaled in Europe until the second half of the 19th
century.
The series of domes of Justinian's Hagia Sofia in Constantinople
(537 A.D), 112 ft (34 m), cause a dynamic flow of solid building
elements together with an interior spaciousness quite different
from the more static Pantheon.
Taj Mahal (1647), Agra, India, 125 ft (38 m) span corbelled
dome
St. Peters, Rome (1590): US Capitol, Washington (1865, double
dome); Epcot Center, Orlando, geodesic dome; Georgia Astrodome,
Atlanta (1980)
These early heavy-weight structures in compression were made
from solid thick surfaces and/or ribs of stone, masonry or
concrete.
The transition to modern long-span structures occurred primarily
during the second half of the 19th century
with the light-weight steel skeleton structures for railway
sheds, exhibition halls, bridges, etc. as
represented by:
Arches: 240-ft (73 m) span fixed trussed arches for St. Pancras
Station, London (1868) 530-ft (162 m) span Garabit viaduct, 1884,
Gustave Eiffel
Frames: 375-ft (114 m) span steel arches for the Galerie des
Machines (1889), Contamin & Dutert
Domes: 207-ft (63 m) Schwedler dome (braced dome, 1874), Vienna
Bridges:1595-ft (486 m) span Brooklyn Bridge, New York, (1883,
Roebling)
Among other early modern long-span structures were also:
Thin-concrete shells, form-passive membranes in compression,
tension and shear: 720-ft (219 m) span CNIT Exhibition Hall Paris,
1958
Space frames surface structures in compression, tension and
bending; Jacob K. Javits Convention Center, New York, 1986, James
Ingo Freed
Tensile membranes almost weightless i.e. form-active structures,
e.g. Fabric domes and HP membranes: tent like roofs for Munich
Olympics, 1972, Frei Otto
Air domes, cable reinforced fabric structures: Pontiac Silver
Dome, Pontiac, 722 ft (220 m), 1975
Tensegrity fabric domes, tension cables + compression struts +
fabrics: Georgia Dome, Atlanta, 770 ft (235 m), 1992
The Building Support Structure
Every building consists of the load-bearing structure and the
non-load-bearing portion. The main load
bearing structure, in turn, is subdivided into:
Gravity structure consisting of floor/roof framing, slabs,
trusses, columns, walls, foundations Lateral force-resisting
structure consisting of walls, frames, trusses, diaphragms,
foundations
Support structures may be classified as,
Horizontal-span structure systems: floor and roof structure,
enclosure structures, bridges
Vertical building structure systems: walls, frames cores, etc.
tall buildings
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Horizontal-span Structure Systems
From a geometrical point of view, horizontal-span structures may
consist of linear, planar, or spatial
elements. Two- and three-dimensional assemblies may be composed
of linear or surface elements.
Two-dimensional (planar) assemblies may act as one- or two-way
systems. For example, one-way floor or planar roof structures (or
bridges) typically consist of linear elements spanning in one
direction where the
loads are transferred from slab to secondary beams to primary
beams. Two-way systems, on the other
hand, carry loads to the supports along different paths, that is
in more than one direction; here members
interact and share the load resistance (e.g. to-way ribbed
slabs, space frames).
Building enclosures may be two-dimensional assemblies of linear
members (e.g. frames and arches), or the
may be three-dimensional assemblies of linear or surface
elements. Whereas two-dimensional enclosure
systems may resist forces in bending and/or axial action,
three-dimensional systems may be form-resistant
structures that use their profile to support loads primarily in
axial action. Spatial structures are obviously
more efficient regarding material (i.e. require less weight)
than flexural planar structures.
From a structural point of view, horizontal-span structures may
be organized as,
Axial systems (e.g. trusses, space frames, cables) Flexural
systems (e.g. one-way and two-way beams, trusses, floor grids)
Flexural-axial systems (e.g. frames, arches) Form-resistant
structures, axial-shear systems: (folded plates, shells, tensile
membranes)
One may distinguish between,
Compressive systems (arches, domes, shells) Tensile systems
(suspended cables, textile fabric membranes,
Some common rigid horizontal-span structure systems are shown on
the following slide:
Straight, folded and bent line elements: beams, columns, struts,
hangars Straight and folded surface elements: one- or two-way
slabs, folded plates, etc. Curved surface elements of synclastic
shape: shell beams, domes, etc. Curved surface elements of
anticlastic shape: hyperbolic paraboloids
Common semi-rigid composite tension-compression systems and
flexible or soft tensile membranes are
organized as:
Single-layer, simply suspended cable roofs: single-curvature and
dish-shaped (synclastic) hanging roofs
Prestressed tensile membranes and cable nets edge-supported
saddle roofs
mast-supported conical saddle roofs
arch-supported saddle roofs
air supported structures and air-inflated structures (air
members)
Cable-supported structures cable-supported beams and arched
beams
cable-stayed bridges
cable-stayed roof structures
Tensegrity structures planar open and closed tensegrity
systems:
cable beams, cable trusses, cable frames
spatial open tensegrity systems: cable domes
spatial closed tensegrity systems: polyhedral twist units
Hybrid structures: combination of the above systems Some typical
examples of horizontal-span structures are,
Examples of horizontal-span roof structure systems Multi-bay
long-span roof structures Cantilever structures
Lateral Stability: Every building consists of the load-bearing
structure and the non-load-bearing portion. The main load-bearing
structure, in turn, is subdivided into:
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(a) The gravity load resisting structure system (GRLS), which
consists of the horizontal and vertical subsystems: Foor/roof
framing and concrete slabs, Walls, frames (e.g., columns, beams),
braced frames, etc., and foundations
(b) The lateral load resisting structure system (LLRS), which
supports gravity loads besides providing lateral stability to the
building. It consists of walls, frames, braced frames, diaphragms,
foundations, and can be subdivided into horizontal and vertical
structure subsystems: Floor diaphragm structures (FD) are typically
horizontal floor structure systems; they transfer
horizontal forces typically induced by wind or earthquake to the
lateral load resisting vertical structures, which then take the
forces to the ground. diaphragms are like large beams (usually
horizontal beams). They typically act like large simply supported
beams spanning between vertical systems.
Vertical structure systems typically act like large cantilevers
spanning vertically out of the ground. Common vertical structure
systems are frameworks and walls.
(c) The non-load-bearing structure, which includes wind bracing
as well as the curtains, ceilings, and partitions that cover the
structure and subdivide the space.
Location of vertical support structure The basic lateral load
resisting structure systems Stability of basic vertical structural
building units Possible location of units in building Lateral
stability of buildings
Basic Concepts of Span: One must keep in mind that with increase
in span the weight increases rapidly while the live loads may
be
treated as constant; a linear increase of span does not result
merely in a linear increase of beam size and
construction method. With increase of scale new design
determinants enter.
The effect of scale is known from nature, where animal skeletons
become much bulkier with increase of
size as reflected by the change from the tiny ant to the
delicate gazelle and finally to the massive elephant.
While the ant can support a multiple of its own weight, it could
not even carry itself if its size were
proportionally increased to the size of an elephant, since the
weight increases with the cube, while the
supporting area only increases with the square as the dimensions
are linearly increased. Thus the
dimensions are not in linear relationship to each other; the
weight increases much faster than the
corresponding cross-sectional area. Hence, either the
proportions of the ant's skeleton would have to be changed, or the
material made lighter, or the strength and stiffness of the bones
increased. It is also
interesting to note that the bones of a mouse make up only about
8% of the total mass in contrast to about
18% for the human body. We may conclude that structure
proportions in nature are derived from
behavioral considerations and cannot remain constant.
This phenomenon of scale is taken into account by the various
structure members and systems as well as by
the building structure types as related to the horizontal span,
and vertical span or height. With increase of
span or height, material, member proportions, member structure,
and structure layout must be
altered and optimized to achieve higher strength and stiffness
with less weight.
For example, for the following long-span systems (rather than
cellular construction where some of the
high-rise systems are applicable) starting at approximately 40-
to 50-span (12 to 15 m) and ranging usually
to roughly the following spans,
Deep beam structures: flat wood truss 120 ft (37 m) Deep beam
structures: flat steel truss 300 ft (91 m) Timber frames and arches
250 ft (76 m) Folded plates 120 ft (37 m) Cylindrical shell beams
180 ft (55 m) Thin shell domes 250 ft (76 m) Space frames, skeletal
domes 400 ft (122 m) Two-way trussed box mega-arches 400 ft (122 m)
Two-way cable supported strutted mega-arches 500 ft (152 m)
Composite tensegrity fabric structures 800 ft (244 m)
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This change of structure systems with increase of span can also
be seen, for example, in bridge design,
where the longer span bridges use the cantilever principle. The
change may be approximated from simple
span beam bridges to cantilever span suspension bridges, as
follows,
beam bridges 200 ft (61 m) box girder bridges truss bridges arch
bridges 1,000 ft (305 m) cable-stayed bridges suspension bridges
(center span) 7,000 ft (2134 m)
total span of AKASHI KAIKO BRIDGE (1998), 13,000 ft (4000 m)
Typical empirical design aids as expressed in span-to-depth
ratios have been developed from experience
for preliminary design purposes in response to various structure
system, keeping in mind that member
proportions may not be controlled by structural requirements but
by dimensional, environmental, and
esthetic considerations. For example,
Deep beams, e.g. trusses, girders L/t 12 or t L/12 Shallow
beams, e.g. average floor framing L/t 24 Slabs, e.g. concrete slabs
L/t 36 Vaults and arches L/t 60 Shell beams L/t 100 Reinforced
concrete shells L/t 400 Lightweight cable or prestressed fabric
structures not an issue
The effect of scale is demonstrated by the decrease of member
thickness (t) as the members become
smaller, that is change from deep beams to shallow beams to
slabs to envelope systems. Each system is
applicable for a certain scale range only, specific structure
systems constitute an optimum solution as
determined by the efficient use of the strength-to-weight and
stiffness-to-weight ratios.
The thickness (t) of shells is by far less than that of the
other systems since they resist loads through geometry as membranes
in axial and shear action (i.e. strength through form), in contrast
to other
structures, which are flexural systems.
The systems shown are rigid systems and gain weight rapidly as
the span increases, so it may be more
efficient to replace them at a certain point by flexible
lightweight cable or fabric structures.
Typical span-to-depth ratios for bending members Structure
systems, preliminary design
The large scale of long-span structures because of lack of
redundancy may require unique building
configurations quite different from traditional forms, as well
as other materials and systems with more
reserve capacity and unconventional detailing techniques as
compared to small-scale buildings.
It requires a more precise evaluation of loading conditions as
just provided by codes. This includes the
placement of expansion joints as well as the consideration of
secondary stresses due to deformation of
members and their intersection, which cannot be ignored anymore
as for small-scale structures.
Furthermore a much more comprehensive field inspection is
required to control the quality during the
erection phase; post-construction building maintenance and
periodic inspection are necessary to monitor
the effects of loading and weather on member behavior in
addition to the potential deterioration of the
materials. In other words, the potential failure and protection
of life makes it mandatory that special
care is taken in the design of long-span structures.
Today, there is a trend away from pure structure systems towards
hybrid solutions, as expressed in geometry, material, structure
layout, and building use. Interactive computer-aided design ideally
makes a
team approach to design and construction possible, allowing the
designer to stay abreast of new
construction technology at an early design stage. In the search
for more efficient structural solutions a new
generation of hybrid systems has developed with the aid of
computers. These new structures do not
necessarily follow the traditional classification presented
before.
Currently, the selection of a structure system, as based on the
basic variables of material and the type and
location of structure, is no longer a simple choice between a
limited number of possibilities. The computer
software simulates the effectiveness of a support system, so
that the form and structure layout as well as
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material can be optimized and nonessential members can be
eliminated to obtain the stiffest structure
with a minimum amount of material.
From this discussion it is clear that with increase of span, to
reduce weight, new structure systems must be
invented and structures must change from linear beams to arched
members to spatial surface shapes to
spatial pre-stressed tensile structures to take fully advantage
of geometry and the strength of material.
In my presentation I will follow this organization by presenting
structural systems in various context. The
examples will show that architecture cannot be defined simply by
engineering line diagrams. To
present the multiplicity of horizontal-span structures is not a
simple undertaking. Some roof structures
shown in the drawings, can only suggest the many possible
support systems.
Examples of horizontal-span roof structure systems The cases may
indicate the difficulty in classifying structure systems
considering the richness of the actual
architecture rather than only structural line diagrams.
A. BEAMS
One-way and two-way floor/roof framing systems (bottom supported
and top supported), shallow beams,
deep beams (trusses, girders, joist-trusses, Vierendeel beams,
prestressed concrete T-beams), etc.
Individual beams Floor/roof framing Large-scale beams including
trusses Supports for tensile columns Cable-supported beams Cable
beams
There is a wide variety of spans ranging from,
Short-span beams are controlled by shear, V, where shear is a
function of the span, L, and the
cross-sectional area, A: V A Medium-span beams are controlled by
flexure, where M increases with the square of the span,
L2,and the cross-section depends on the section modulus, S: M S
Long-span beams are controlled by deflection, , where deflection
increases to the forth power of
L, (L4) and the cross-section depends on the moment of inertia I
and the modulus of elasticity E
(i.e. elastic stiffness EI ): EI
The following examples clearly demonstrate that engineering line
diagrams cannot define the full richness
of architecture. The visual expression of beams ranges from
structural expressionism (tectonics),
construction, minimalism to post-modern symbolism. The visual
expression of beams ranges from structural expressionism
(tectonics), construction, minimalism to post-modern symbolism.
They may be,
planar beams spatial beams (e.g. folded plate, shell beams ,
corrugated sections) space trusses.
They may be not only the typical rigid beams but may be flexible
beams such as
cable beams. The longitudinal profile of beams may be shaped as
a funicular form in response to a particular force
action, which is usually gravity loading; that is, the beam
shape matches the shape of the moment diagram
to achieve constant maximum stresses.
Beams may be part of a repetitive grid (e.g. parallel or two-way
joist system) or may represent individual
members; they may support ordinary floor and roof structures or
span a stadium; they may form a stair, a bridge, or an entire
building. In other words, there is no limit to the application of
the beam principle.
Individual Beams: - Railway Station, Munich, Germany Atrium,
Germanisches Museum, Nuremberg, Germany Pedestrian bridge Nuremberg
Dresdner Bank, Verwaltungszentrum, Leipzig, 1997, Engel und
Zimmermann Arch
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Shanghai-Pudong International Airport, 2001, Paul Andreu
principal architect, Coyne et Bellier structural engineers
Petersbogen shopping center, Leipzig, 2001, HPP
Hentrich-Petschnigg The asymmetrical entrance metal-glass canopies
of the National Gallery of Art, Stuttgart, J. Stirling (1984),
counteract and relieve the traditional post-modern classicism of
the
monumental stone building; they are toy-like and witty but not
beautiful. Documentation Center Nazi Party Rally Grounds
(Nuremberg, 2001, Guenther Domenig
Architect) is located in the unfinished structure of the
Congress Hall. It gives detailed information
about the history of the Party Rallies and exposes them as
manipulative rituals of Nazi
propaganda. A glass and steel gangway penetrates the North wing
of the Congress Hall like a
shaft, the Documentation Center makes a clear contemporary
architectural statement.
Floor/ Roof Framing Floor/ roof framing systems Floor framing
structures RISA floor framing example Chifley tower , Sydney, 1992,
Kohn, Pederson, Fox Farnsworth House, Mies van der Rohe, Plano, Ill
(1950), USA, welded steel frame Residence, Aspen, Colorado, 2004,
Voorsanger & Assoc., Weidlinger Struct. Eng. European Court of
Justice, Luxemburg, 1994, Atelier d'Architecture Paczowski Fritsch
Associs Central Beheer, Apeldorn, NL, Herman Hertzberger (1972):
adjacent tower element about 27
x 27 ft (8.23 m) square with 9 ft wide spaces between, where
basic square grid unit is about
9 ft (2.74 m); precast concrete elements; people create their
own environments.
Xiangguo Si temple complex, downtown Kaifeng
Large-scale beams including trusses: Beam trusses Atrium,
Germanisches Museum, Nuremberg, Germany: the bridge acts not just
as connector but
also interior space articulation.
National Gallery of Art, East Wing, Washington, 1978, I.M. Pei
Library, University of Bamberg TU Munich Library Gainesville, FL TU
Stuttgart San Francisco Terminal, 2001, SOM Documentation Center
Nazi Party Rally Grounds, Nuremberg,, 2001, Guenther Domenig Sobek
House, 2001, Stuttgart, Werner Sobek Integrated urban buildings,
Linkstr. Potsdamer Platz), Richard Rogers, Berlin, 1998 Petersbogen
shopping center, Leipzig, 2001, HPP Hentrich-Petschnigg Tokyo
International Forum, 1997, Rafael Vignoli Arch, Kunio Watanabe
Struct. Eng. Ski Jump Berg Isel, Innsbruck, 2002, Zaha Hadid
Supports for tensile columns 5-story Olivetti Office Building,
Florence, Italy, Alberto Galardi, 1971: suspended construction
with prestressed concrete hangers sits on two towers supporting
trusses, which in turn carry the
cross-trusses
Shanghai-Pudong Museum, Shanghai, (competition won 2002), von
Gerkan Berlin Stock Exchange, Berlin, Germany, 1999, Nick Grimshaw
Centre George Pompidou, 1978, Paris, Piano & Rogers 43-story
Hongkong Bank, Hong Kong, 1985, Foster/Arup: 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 building celebrates technology and architecture
of science as art. It expresses the
performance of the building and the movement of people. The
support structure is clearly
expressed by the clusters of 8 towers forming 4 parallel
mega-frames. A mega-frame consists of
2 towers connected by cantilever suspension trusses supporting
the vertical hangers which, in
turn,support the floor beams. Obviously, the structure does not
express structural efficiency.
Beam buildings
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Visual study of beam buildings Seoul National University Museum,
Rem Koolhaas, 2006 William J. Clinton Presidential Center, Little
Rock, AR, 2004, Polshek Partnership Landesvertretung von
Baden-Wuertemberg, Berlin, Dietrich Bangert, 2000 Embassy UK,
Berlin, Michael Wilford, 2000 Super C, RWHA, Aachen, 2008 WDR
Arcades/Broadcasting House, Cologne, 1996, Gottfried Bhm; this
buildings hiuses the
Radio and television production studios of the largest German
broadcasting station. The WDR-
Arkaden are architecturally one of the most interesting
buildings in Cologne. The shopping arcade
was benn designed by Gottfried Bhm. Some people characterise it
as some batched container.
Shanghai Grand Theater, Jean-Marie Charpentier, architect
(1998): inverted cylindrical tensile shell
Lehrter Bahnhof, Berlin, 2006, von Gerkan, Marg and Partners La
Grande Arche, Paris, 1989, Johan Otto von Sprechelsen/ Peter Rice
for the canopy Fuji Sankei Building, Tokyo, 1996, Kenco Tange Sharp
Centre for Design, Ontario College of Art & Design, Toronto,
Canada, 2004, Alsop
Architects
Porsche Museum building: images authorised by Delugan Meissl
Architects 2007 Abu Dhabi Performing Arts Centre, Zaha Hadid, the
centre,2007
Cable-supported beams and cable beams Single-strut and
multi-strut cable-supported beams Erasmusbridge, Rotterdam, 1996,
Ben Van Berkel Golden Gate Bridge, San Francisco, 1936, C.H.
Purcell Old Federal Reserve Bank Building, Minneapolis, 1973,
Gunnar Birkerts, 273-ft (83 m) span truss
at top
World Trade Center, Amsterdam, 2003 (?), Kohn, Pedersen &
Fox Luxembourg, 2007 Kempinski Hotel, Munich, Germany, 1997, H.
Jahn/Schlaich. Also here, the hotels open grand
atrium is more than a lobby. The new technology of the 40-m span
glass and steel roof features a
construction with its own aesthetics reflecting a play between
artistic, architectural mathematical,
and engineering worlds. The depth of the diagonal 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.
Shopping areas, Berlin, Linkstr., Rogers, 1998 The main
structure for the Wilkhahn Factory, Bad Muender, Germany, 1992, by
Thomas Herzog
Arch., is parallel to the faade (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 seems to give lateral support to
the post-beam timber structure to
resist wind with a minimum effort.
Mercedes-Benz Center am Salzufer, Berlin, 2000, Lamm, Weber,
Donath und Partner Shopping Center, Stuttgart Cologne/Bonn Airport,
Germany, 2000, Helmut Jahn Arch., Ove Arup USA Struct. Eng Lehrter
Bahnhof, Berlin, 2006, von Gerkan, Marg and Partners Debis Theater,
Berlin, 1998, Renzo Piano Shanghai-Pudong International Airport,
2001, Paul Andreu principal architect, Coyne et Bellier
structural engineers
Ski Jump Voightland Arena, Klingenthal, 2007,
m2r-architecture
B. FRAMES
Gables, A-frames, Arches, Glass enclosures, etc.: parallel,
two-way, spatial/polyhedral, trees Crown Hall, IIT, Chicago, 1955,
Mies van der Rohe; the 120-ft (37 m) span building has become a
symbol for the celebration of the portal frame; Mies articulated
the power and beauty of the post-
beam structure by exposing the lightness of the steel skeleton
as contrasted by the glass surface;
the roof platform is suspended from the welded plate girders
that are spaced at 60 ft (18 m).
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Visual study of single-bay portal frames Single-story, multi-bay
frame systems Visual study of multiple-span frame structures Postal
Museum, Frankfurt, Germany, 1990, Guenter Behnisch Arch.: space
dynamics through
fragmentation
Indeterminate portal frames under gravity loads Indeterminate
portal frames under lateral load action Sainsbury Centre for Visual
Arts, UK, 1978, Norman Foster Glass Cube, Art Museum Stuttgart,
2005, Hascher und Jehle Arch Visual study of Frames and arches
Response of typical gable frame roof enclosures to gravity loading
Pitched roof structures Joist roof construction Rafter roof
construction Inclined frame structures Project for Fiumicino
Airport, Rome, 1957, Nervi etc. The Novotel Belfort, Belfort,
France, 1994, Bouchez BMW Plant Leipzig, Central Building, 2004,
Zaha Hadid San Diego Library, 1970, William L. Pereira 798 Beijing
Art Factory, Beijing, 1956, the shape of the supporting frames
(i.e. roof shape)
depends on ventilation and lighting of the sheds.
Bus Stop Aachen, 1998, Peter Eisenman, folded steel structure
that resembles a giants claw grasping the paving, or the folded
steel shelter perches crablike on the square
Zueblin AG Headquarters, Stuttgart, 1985, Gottfried Boehm:
hollow central glass-covered atrium space between solid building
masses; stair towers and pedestrian bridges as interior
connectors;
celebration of articulated precast concrete cladding.
Miyagi Stadium, Sendai City, Japan, 2000, Atelier Hitoshi
Abe
Arches Study of curvilinear patterns Arches as enclosures Visual
study of arches Visual study of lateral thrust Olympic Stadium
Montreal, 1975, Roger Taillibert Dresden Main Train Station,
Dresden, 2006, Foster Lanxess Arena, Cologne, 1998, Peter Bhm
Architekten United Airlines Terminal at OHare Airport, Chicago,
1987, H. Jahn Museum of Roman Art, Mrida, Spain 1985, Jose Rafael
Moneo 'Glass Worm' building - new Peek & Cloppenburg store,
Cologne, Renzo Piano, 2005 City of Arts & Sciences, Valencia
,Spain ,Santiago Calatrava, 2000 Geschwungene Holzbruecke bei
Esslingen (Spannbandbruecke), 1986, R. Dietrich La Devesa
Footbridge, Ripoll, Spain, 1991, S. Calatrava, torsion Bac de Roda
Felipe II Bridge, 1987, west Barcelona, Santiago Calatrava,
Architect Bridge over the Rhein-Herne-Canal, BUGA 1997,
Gelsenkirchen, Stefan Polnyi The Metro station at Blaak, Rotterdam,
1993, Harry Reijnders of Movares; the arch spans 62.5 m,
dome diameter is 35 m
Kansai International Airport Terminal in Osaka, Japan, 1994 ,
Renzo Piano Terminal 5 Roof Heathrow Airport, London, 2005,
Rogers/Arup Ningbo Air terminal Shenyang Taoxian International
Airport Chongqing Airport Terminal, 2005, Llewelyn Davies Yeang and
Arup San Giovanni Rotondo, Italy, 2004, Renzo Piano Center Paul
Klee, Bern, 2005, Renzo Piano Waterloo Terminal, London, 1993,
Nicholas Grimshaw + Anthony Hunt BCE Place, Toronto, 1992, Santiago
Calatrava Subway Station to Allians Stadium, Froettmanning, Munich,
2004, Bohn Architekten, fabric
membranes
Olympic Stadium Athens, 2004, Santiago Calatrava New TVG
Station, Liege, Belgium, 2008, Santiago Calatrava
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10
C. CABLE-STAYED ROOF STRUCTURES
Examples of cable-stayed roof structures range from long-span
structures for stadiums, grandstands,
hangars, and exhibition centers, to smaller scale buildings for
shopping centers, production or research
facilities, to personal experiments with tension and
compression. Many of the general concepts of cable-stayed bridges,
as discussed in the previous section, can be transferred to the
design of cable-stayed roof
structures. Typical guyed structures, used either as planar or
spatial stay systems, are the following:
Cable-stayed, double-cantilever roofs for central spinal
buildings
Cable-stayed, single-cantilever roofs as used for hangars and
grandstands
Cable-stayed beam structures supported by masts from the
outside
Spatially guyed, multidirectional composite roof structures
Visual study of cable-supported structures Force flow in
cable-supported roofs Patscenter, Princeton, 1984, Rogers/Rice, the
building consists of parallel planar guyed structures
along the central spine consisting of c. 9m 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 tubular
hangers act in compression.
Fleetguard Factory, Quimper, France, 1981, Richard Rogers
Shopping Center, Nantes, France, 1988, Rogers/Rice, 94-ft (29 m)
high tubular masts support the
94-ft (29 m) framework in a spatial fashion from above without
penetration of the roof. Only
certain combinations of the 3-dimensional network of tension
rods and compression struts are
activated under various load actions.
Horst Korber Sports Center, Berlin, 1990, Christoph Langhof,
quite different in spirit are the slender and minimal abstract
planar, tree-like c.30-m high masts with their five branches linked
by
cables from which the light cable roof trusses are hung. The
symmetrical abstract forms of the masts are completely opposite in
expression from the tectonic shapes of most other examples.
The Charlety Stadium, Cite Universitaire, Paris, 1994, Henri and
Bruno Gaudin Lufthansa Hangar, Munich, 1992, Buechl + Angerer, the
immense 153-m span roof is supported
by the diagonal cables suspended from the c.56-m tall concrete
pylons
Bridge, Hoofddorp, Netherlands, 2004, Santiago Calatrava The
University of Chicago Gerald Ratner Athletic Center, Chicago, 2002,
Cesar Pelli Melbourne Cricket Ground Southern Stand , 1992, Tomkins
Shaw & Evans / Daryl Jackson Pty Lt Bruce Stadium , Australian
Capital Territory, 1977, Philip Cox, Taylor and Partners City of
Manchester Stadium, UK, 2003, Arup Munich Airport Center, Munich,
Germany, 1997, Helmut Jahn Arch.: the open public atrium as
transition, building blocks form walled boundaries to a square
which is covered by a transparent roof hanging from stayed cables,
with a minimum of structure that gives a strong identity to
space
- the new technology features construction with its own
aesthetics reflecting a play between
artistic, architectural mathematical, and engineering
worlds.
D. FORM-PASSIVE SURFACE STRUCTURES: hard shells (rotational,
synclastic forms vs. translational, anticlastic surfaces)
Slabs Folded plates Space frames Tree columns Dome structures
Thin shells Ribbed shells
Slabs Visual study of floor/ roof structures 1, 2
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11
Stress flow, multi-story building in concrete and steel Stress
flow, Hospital, Dachau, Germany Computer modelling, ramp for
parking garage Paul Lbe and Marie-Elisabeth Lders House in the
German Government Building, Berlin, 2001,
Stephan Braunfels
Government building, Berlin, 2001 Federal Chancellery Building,
Berlin, 2001, Axel Schultes and Charlotte Frank Glasshouse, 1949,
Philip Johnson New National Gallery, Berlin, 1968, Mies van der
Rohe Sichuan University, Chengdu, College for Basic Studies, 2002
Civic Center, Shenzhen Science and Technology Museum Shanghai,
2002, RTKL/Arup Akron Art Museum, Akron, 2007, Wolf Prix and Helmut
Swiczinsky (Himmelblau) BMW Welt, Munich, 2007, Coop Himmelblau
Folded Plates: trussed vs. concrete, parallel vs. triangular
folds, flat vs. warped surfaces, two-way warped surfaces
Folded plate structures Folded plate structure systems Alte
Kurhaus, Aachen, Germany St. Foillan, Aachen, Leo Hugot Arch.
Institute for Philosophy, Free University, Berlin, 1980s, Hinrich
and Inken Balle. Glass, openness,
and light-flooded rooms: the architects Hinrich and Inken Baller
created transparency in the 1980s
in the design of the new building for the Institute for
Philosophy in Habelschwerdter Allee. This
building was the first university institute designed in the
style of a villa to fit in with the single-
family-house character of the district of Dahlem.
Church of the Pilgrimage, Neviges, Germany, Gottfried Boehm,
1968, Velbert, Germany Air force Academy Chapel, Colorado Springs,
1961, Walter Netsch (SOM) Center Le Corbusier, Zurich, 1967, Le
Corbusier, hipped and inverted hipped roof, each composed
of four square steel panels
21_21 Design Sight, Tokyo, 2007, Tadao Ando; the building is a
low-rise structure consisting of one ground floor and one
underground floor. Most of the volume of the building, which has
a
unique form featuring a roof made from giant steel plates that
slope gently down to the ground, is
buried underground. Once inside, the space opens out on a scale
unimaginable given the building's
unobtrusive exterior. The ground floor houses the entrance and
reception area, while the
underground floor houses two galleries and a triangular sunken
court. A feature of the building is
that it is encased in the longest section of double-glazing in
Japan.
Salone Agnelli, Turin Exhibition Hall, 1948, Pier Luigi Nervi
Kimmel Center for the Performing Arts, Philadelphia, Rafael Vinoly,
2001, steel-and-glass barrel
vault (160 ft high), the roof structure uses the depth of the
vaulted section to creat a vierendeel
truss that arches across the atrium, the trusses are propped
against each adjacent element to
provide a folded plate action that resists the longitudinal wind
loads Sydney Olympic Train Station, Homebush, Hassell Pty. Ltd
Arch, Tierney & Partners Struct.
Eng., 1998, single span vaulted 'leaf' roof truss, repeated
folded vault configuration , Plan shape
rectangular - 200m x 35m, 18 modules spaced at 12m , 14m long
arched entrance canopy, 5.5m
wide side awning, support structures columns, buttresses, arched
trusses Combining the use of
an arch with that of a truss resulted in two layers. First, the
two arches in each truss, which use
arch action to span a large distance and provide a column, free
space. Secondly, the truss to
provide depth (to take bending moments) in the roof plane which
is important to resist asymmetric
loads under wind pressure in addition to resisting uplift
forces. To cater for gravitational and uplift
forces, the arched truss is designed to cater for both
compression as well as tension. Arched roof
truss members: 355CHS twin arch at the ridge (centre of leaf)
and 355CHS inclined arches at the
bottom (leaf's border). Each arch is composed of three sections
joined together. Truss web
members: 200 x 100 RHS with tubular bracing, link top and bottom
arches. Roof cladding: speed deck 500, zincalume finish ribbed
cladding. Internal roof lining: perforated aluminium sheets.
Addition to Denver Art Museum, 2006, Daniel Libeskind/ Arup
Eng.
Space Frames Polyhedral roof structures Single-layer
three-dimensional frameworks
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Double-layer space frame systems 1 Double-layer space frame
systems 2 Common polyhedra derived from cube Generation of space
grids by overlapping planar networks National Swimming Center,
Beijing, RANDOM ARRANGEMENT OF SOAP BUBBLES Professor Weaire and
his research assistant Dr Phelan at Trinity College, Dublin, that
provided us
with the answer for the Water Cube. The curious thing about
Weaire Phelan foam is that, despite
its complete regularity, when viewed at an arbitrary angle it
appears to be random and organic.
To construct the geometry of the structure of our building, we
start with an infinite array of foam
(oriented in a particular way) and then carve out a block equal
to the size of our building 177 x 177 x 31 cubic metres. The three
major internal volumes are subtracted from this foam block and
the result is the geometry of the structure. The structure is
then clad with ETFE pillows inside and
out to achieve the desired organic look and to work as an
efficient insulated greenhouse. So, in
searching for the most efficient way of subdividing space, we
found a structure based on the
geometry of soap bubbles, and clad with plastic pillows that
look like bubbles. And inside, all the
water of a swimming centre! We were confident that we had a
winning scheme; our next challenge
was to convey the idea accurately to the judges. We decided to
build an accurate physical
model of all 22,000 structural elements and 4,000 (different)
cladding panels. The only way to do this seemed to be Rapid
Prototyping machinery, commonly used in the manufacturing and
automobile industries. It took us many weeks to learn enough
about the CAD modelling and the
data translation required just to make the structural model.
With two days left, the structural model
was flown from Melbourne to Beijing, where it was joined to a
handmade plastic skin (we just
couldnt draw all the different pillow shapes in time), and the
model was complete. In July 2003, we were announced as the winners
of the competition and
Strurctural behavior of double-layer space frames Common space
frame joints Case study of flat space frame roofs Other space frame
types Example Hohensyburg Robson Square, Vancouver, 1980, Arthur
Erickson Jacob K. Javits Convention Center, New York, 1986, James
Ingo Freed/ Weidlinger Dvg-Administration, Hannover, 2000,
Hascher/Jehle Crystal Cathedral, Garden Grove, CA, 1980, Philip
Johnson Kyoto JR Station, Kyoto, Japan, 1998, Hiroshi Hara Arch.:
the urban mega-atrium. The building
has the scale of a horizontal skyscraper - it forms an urban
mega-complex. The urban landscape
includes not only the huge complex of the station, but also a
department store, hotel, cultural
center, shopping center, etc. The central concourse or atrium is
470 m long, 27 m wide, and 60 m
high. It is covered by a large glass canopy that is supported by
a space-frame. This space acts a
gateway to the city as real mega-connection.
Tomochi Forestry Hall, Kumamoto, Japan, 2005, Taira Nishizawa
Architects National Swimming Center, Beijing, 2008, Herzog de
Meuron; Engineer: Tristram Carfrae of
Arup, The Beijing National Swimming Centre, better known as the
'Water Cube', Arup Arch and
Eng., will be one of the most dramatic and exciting venues to
feature sporting events for the 2008
Olympics. The structure of the Water Cube is based on the most
effective sub-division of three-
dimensional space - the fundamental arrangement of organic cells
and the natural formation of
soap bubbles. The random-looking structure is based on the
formation of soap bubbles the most efficient sub-division of
three-dimensional space.
Tree Columns: parallel, two-way, spatial/polyhedral, trees
Ningbo Air Terminal Shenyang Airport Terminal Stanted Airport,
London, UK, 1991, Norman Foster/ Arup Terminal 1 at Stuttgart
Airport, 1991, von Gerkan & Marg. The huge steel trees of the
Stuttgart
Airport Terminal, Stuttgart, Germany 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).
Dome Structures: typical domes, inverted domes, segments of dome
assembly, etc. Major skeleton dome systems
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Dome structure cases Little Sports Palace, Rome, Italy, 1960
Olympic Games, Pier Luigi Nervi U.S. Pavilion, Toronto, Canada,
Expo 67, Buckminster Fuller, 250 ft (76 m) diameter sphere,
double-layer space frame
Jkai Baseball Stadium, Odate, Japan Philological Library, Free
University, Berlin, 2005, N. Foster National Grand Theater,
Beijing, 2006, Paul Andreu Bent surface structures Grand Louvre,
Paris, 1993, I. M. Pei MUDAM, Museum of Modern Art, Luxembourg,
2006, I.M. Pei The dome used for dwelling Ice Stadium, Davos,
Switzerland Reichstag, Berlin, Germany, 1999, Norman Foster Arch/
Leonhardt & Andrae Struct. Eng. Beijing National Stadium,
Beijing, 2008, Herzog and De Meuron Arch/ Arup Eng. The Bird's
Nest was designed by the Swiss firm Herzog & De Meuron. This
firm's previous projects include
the renovation of an old power station on the banks of the
Thames in London, which was turned
into the Tate Modern Art Museum. Herzog & De Meuron also won
last year's Sterling Prize for
Architecture for their design of the Laban Dance Centre in a
rundown area of London.
Thin shells Shell shapes may be classified as follows:
Geometrical, mathematical shapes Conventional or basic shapes:
single-curvature surfaces (e.g. cylinder, cone), double-
curvature surfaces (e.g. synclastic surfaces such as elliptic
paraboloid, domes, and
anticlastic surfaces such as hyperbolic paraboloid, conoid,
hyperboloid of revolution)
Segments of basic shapes, additions of segments, etc.
Translation and/or rotation of lines or surfaces Corrugated
surfaces Complex surfaces such as catastrophe surfaces
Structural shapes Minimal surfaces, with the least surface area
for a given boundary,
constant skin stress, and constant mean curvature
Funicular surfaces, which is determined under the predominant
load Optimal surfaces, resulting in weight minimization Free-form
shells, may be derived from experimentation Composed or sculptural
shapes
Introduction to shells and cylindrical shells Surface structures
in nature Surface classification 1 and 2 Examples of shell form
development through experimentation Basic concepts related to
barrel shells Slab action vs. beam action Cylindrical shell-beam
structure Vaults and short cylindrical shells Cylindrical grid
structures Various cylindrical shell types Cologne Cathedral,
Germany St. Lorenz, Nuremberg, Germany, 14th cent Airplane hangar,
Orvieto 1, 1939, Pier Luigi Nervi Zarzuela Hippodrome, Madrid,
1935, Eduardo Torroja Kimbell Art Museum, Fort Worth, 1972, Louis
Kahn Terminal 2F, Orly Airport, Paris, 2002, Paul Andreu,
elliptical concrete vault. As for section E,
while the public area is identical to the one of section F, the
boarding area consists in a long hall-
way, with an elliptical vault made out of concrete. Passengers
are more likely to encounter longer
walking distances in this case, than in Terminal 2F. I should
underscore the fact that these two designs recall the ones of the
two terminals at Orly airport.
Alnwick Gardens Visitor Center roof, UK, 2006, Hopkins Arch.,
Happold Struct. Eng. History Museum Courtyard Roof, Hamburg, 1989,
von Gerkan Marg und Partner Dz Bank, glass roof, Berlin, 2001,
Gehry + Schlaich
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14
Exhibition hall Leipzig, Germany, 1996, von Gerkan, GMP, in
cooperation with Ian Ritchie P&C Luebeck, Luebeck, 2005,
Ingenhoven und Partner, Werner Sobek, At the very heart of
Lbeck's historical centre a new commercial building was
constructed. The building had to be
inserted very carefully into the UNESCO-listed Old Town. For
this reason the roof played a major
role in the design concept. The roof consists of 16 shells in
reinforced concrete that have a
thickness of 14 cm each. In plan view the shells are trapezoids
that are arranged in alternating alignments. The shells span 8.75 m
in cross direction and up to 28 m in machine direction.
Central Railway Station Cologne, Germany CNIT Exhibition Hall
Paris, 1958, Bernard Zehrfuss Arch, Nicolas Esquillon Eng.
Thin-concrete
shells, form-passive membranes in compression, tension and
shear: 720-ft (219 m) span
Other shell forms Dome shells on polygonal base Keramion
Ceramics Museum, Frechen, 1971, Peter Neufert Arch., the building
reflects the nature
of ceramics
Kresge Auditorium, MIT, Eero Saarinen/Amman Whitney (1955), on
three supports Ecological Center, St. Austell, Cornwall,
England,1996, Nicholas Grimshaw, Anthony Hunt; the
biomes are constructed from a tubular steel frame with mostly
hexagonal transparent panels (there
are a few pentagonal ones) made from a complex plastic known as
ETFE (it was decided very
early on that glass was out of the question, being too heavy and
potentially dangerous). The "panes" of the biome are created from a
triple layer of thin UV-transparent ETFE film, inflated to
create a large space between the two sides and trapping heat
like double-glazed windows. The
plastic is resistant to most stains, which simply wipe off in
the rain, although if required, cleaning
is performed by abseilers. Although the plastic is prone to
punctures, these can be fixed with
ETFE tape. The structure is completely self-supporting, with no
internal supports, and takes the
form of a geodesic structure. The panels vary in size up to 9 m
across, with the largest at the top of
the structure.
Delft University of Technology Aula Congress Centre, 1966,
Bakema Hyperbolic paraboloids Hypar units on square grids Case
study of hypar roofs Membrane forces in a basic hypar unit Some
hypar characteristics Examples Felix Candela, Mexico Bus shelter,
Schweinfurt Greenwich Playhouse, 2002, Austin/Patterson/Diston
Architects folded plate behavior Garden Exhibition Shell Roof,
Stuttgart, 1977, Jrg Schlaich Expo Roof, Hannover, EXPO 2000, 2000,
Thomas Herzog Intersecting shells Other surface structures TWA
Terminal, New York, 1962, Saarinen Sydney Opera House, Australia,
1972, Joern Utzon/ Ove Arup Mannheim Exhibition, 1975, Frei Otto
etc., the catenary surface geometry of the wooden grid
shell was derived by inverting a hanging chain model to a
standing position and thus is curved
primarily synclastically
DZ Bank, amoeba-like auditorium, Berlin, 2001, Gehry + Schlaich
Phaeno Science Centre Wolfsburg, Germany, 2005, Zaha Hadid BMW
Welt, Munich, 2007, Coop Himmelblau Centre Pompidou-Metz, 2008,
architects Shigeru Ban and Jean de Gastines Fisher Center, Bard
College, NY, Frank Gehry, DeSimone, 2004 A model of the London
Olympic Aquatic Center, 2004 by Zaha Hadid. Congress Center EUR
District, Rome, Italy, Massimiliano Fuksa. Congress Center EUR
District,
Rome, Italy, Massimiliano Fuksa. The building is basically
large, 30 meters high, translucent container that extends
lengthways. On each side a square opens on to the immediate area
and the
city. The first converses directly continuously with the local
area and can be crossed from viale
Europa to viale Shakespeare. The second, a space that can be
composed freely using moveable
structures, is for welcoming conference participants and
accompanying them to the various rooms
in the center. Inside this shell, a 3,500 square meter steel and
teflon cloud, suspended above a
surface area of 10.000 square meter, is designed to hold a 2.000
square meter auditorium and
various meeting rooms. When the cloud, supported by a thick
network of steel cables and
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15
suspended between the floor and the ceiling of the main
conference hall, is lit up, the building
seems to vibrate. The construction also changes completely
depending on the viewpoint of the
observer.
Metropol Parasol", Jrgen Mayer Arch, a redevelopment project by
J. Mayer H. for Plaza de la Encarnacion in Seville, Spain is one of
the most striking projects I've seen in ages. Amazingly, it's
under construction and is expected to be complete this year.
E. FORM-ACTIVE SURFACE STRUCTURES: soft shells, TENSILE
MEMBRANES, textile fabric membranes, cable net
structures, tensegrity fabric composite structures
Suspended surfaces (parallel, radial)
Anticlastic, pre-stressed structures Edge-supported saddle
roofs
Mast-supported conical saddle roofs
Arch-supported saddle roofs
Pneumatic structures Air-supported structures
Air-inflated structures (air members)
Hybrid air structures
Tensegrity structures
In contrast to traditional surface structures, tensile cablenet
and textile structures lack stiffness and weight.
Whereas conventional hard and stiff structures can form linear
surfaces, soft and flexible structures must
form double-curvature anticlastic surfaces that must be
prestressed (i.e. with built-in tension) unless they
are pneumatic structures. In other words, the typical
prestressed membrane will have two principal
directions of curvature, one convex and one concave, where the
cables and/or yarn fibers of the fabric are
generally oriented parallel to these principal directions. The
fabric resists the applied loads biaxially; the
stress in one principal direction will resist the load (i.e.
load carrying action), whereas the stress in the perpendicular
direction will provide stability to the surface structure (i.e.
prestress action). Anticlastic
surfaces are directly prestressed, while synclastic pneumatic
structures are tensioned by air pressure. The
basic prestressed tensile membranes and cable net surface
structures are
Suspended Surfaces: parallel, radial Simply-suspended structures
Dulles Airport, Washington, 1962, Eero Saarinen/Fred Severud,
161-ft suspended tensile vault Trade Fair Hall 26, Hanover, 1996,
Herzog/ Schlaich National Indoor Sports and Training Centre,
Australia, 1981, Philip Cox Olympic Stadium for 1964 Olympics,
Tokyo, Kenzo Tange/Y. Tsuboi, the roof is supported by
heavy steel cables stretched between concrete towers and tied
down to anchorage blocks.
Anticlastic, Prestressed Membranes Tent architecture Dorton
(Raleigh) Arena (1952), North Carolina, Matthew Nowicki, with
Frederick Severud Subway Station to Allianz Arena, Stadium Railway
Station Froettmanning, Munich IAA 95 motor show, Frankfurt New roof
for the Olympic Stadium Montreal, 1975, Roger Taillibert Grand Arch
de la Defense, Paris, 1989, Paul Andreu Olympic Stadium, Munich,
1972, Behnich/Frei Otto/Leonardt, saddle-shaped prestressed
membranes
King Fahd International Stadium, Riyadh, Saudi Arabia, 1986,
Horst Berger Canada Place, Vancouver, 1986, Eberhard Zeidler/ Horst
Berger San Diego Convention Center, 1989, Arthur Erickson/ Horst
Berger Schlumberger Research Center, Cambridge, UK (1985,
Hopkins/Hunt); The ship like masts and
rigging support the spatial domelike undulating tensile fabric
membrane. The 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
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16
(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.
Denver International Airport Terminal, Denver, 1994, Horst
Berger/ Severud,the folded Teflon-coated fiberglass membrane spans
about 220 ft (67 m), the roof weighs less than 2 psf (96 Pa)
Hybrid tensile surface structures
Pneumatic structures
Air-supported structures high-profile ground-mounted air
structures
berm- or wall-mounted air domes
low-profile roof membranes
Air-supported structures form synclastic, single-membrane
structures, such as the typical basic domical
and cylindrical forms, where the interior is pressurized; they
are often called low-pressure systems
because only a small pressure is needed to hold the skin up and
the occupants dont notice it.
Pressure can be positive causing a convex response of the
tensile membrane or it can be negative (i.e.
suction) resulting in a concave shape. The basic shapes can be
combined in infinitely many ways and
can be partitioned by interior tensile columns or membranes to
form chambered pneus.
The typical normal operating pressure for air-supported
membranes in the USA is in the range of 4.5 to
8 psf (22 kg/m2 to 39 kg/m2) or roughly 1.0 to 1.5 inches of
water as read from a water-pressure gage.
Pneumatic structures Low-profile, long-span roof structures Soap
bubbles To house a touring exhibition Examples of pneumatic
structures Norways National Galery, Oslo, 2001, Magne Magler Wiggen
Architect Effect of wind loading on spherical membrane shapes Eden
Project in Cornwall/England Humid Tropics Biome, 1996, Nicholas
Grimshaw, A. Hunt Metrodome, Minneapolis, 1981, SOM
Air inflated structures: air members Air inflated structures or
simply air members, are typically,
high-pressure tubes lower-pressure cellular mats: air
cushions
Air members may act as columns, arches, beams, frames, mats, and
so on; they need a much higher
internal pressure than air-supported membranes.
Expo02 Neuchatel, 2002, air cussion, ca 100 m dia. Roman Arena
Inflated Roof, Nimes, France, 1988, Schlaich Festo A.G.
Stuttgart
Tensegrity Structures
Buckminster Fuller described tensegrity as, small islands of
compression in a sea of tension. Ideal tensegrity structures are
self-stressed systems, where few non-touching straight compression
struts are
suspended in a continuous cable network of tension members. The
pretensioned cable structures may be
either self-balancing that is the forces are balanced internally
or non-self-balancing where the forces are
resisted externally by the support structure. Tensegrity
structures may be organized as
Planar open tensegrity systems: cable beams, cable trusses,
cable frames
Planar closed tensegrity systems: cable beams, cable trusses,
cable frames
Spatial open tensegrity systems
Spatial closed tensegrity systems
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17
Tensegrity sculptures by Kenneth Snelson Karl Ioganson, 1920,
Russian artist TENSEGRITY TRIPOD DOUBLE - LAYER TENSEGRITY DOME
Olympic Fencing and Gymnastics Arenas, Seoul, 1989, Geiger Georgia
Dome, Atlanta, 1992, Levi/Weidlinger, hypar-tensegrity dome.
Georgia Dome, Atlanta,
Weidlinger, Structures such as the Hypar-Tensegrity Dome require
special analysis and could not
have been realized without the availability of computers and
nonlinear programs. The world's
largest cable dome, was completed for the 1992 football season
in Atlanta, was the centerpiece of
the 1996 Olympic Games. Spanning 766 ft x 610 ft (233.5 m x 186
m), it will be the first Hypar-
Tensegrity Dome. This new cable supported teflon-coated fabric
roof is based on the tensegrity
principles first enunciated by Buckminster Fuller and Kenneth
Snelson. Because of the large
deformation characteristics of this type of structures, special
geometric nonlinear analysis is
required.