3. TYPE FORM DESCRIPTION EXAMPLES
1. CABLE STRUCTURES
Cable structure, Form of long-
span structure that is subject to
tension and uses suspension
cables for support. Are highly
efficient.
2. TENT STRUCTURES
A tensile structures carry only tension
and no compression or bending.
s u p p o r t e d b y s o m e f o r m o f
compression or bending elements,
such as masts, compression rings or
beams.
3. ARCHED STRUCTURES
An arch is a vertical curved
structure that spans an elevated
space and may or may not
support the weight above it
4. PNEUMATIC STRUCTURES
A pneumatic structure is a system of
components that is supported by
air.The components of a pneumatic
structure consist of a membrane,
supporting cables, and anchorage
system and an HVAC system.
TYPES OF FORM ACTIVE STRUCTURES
4.
5. CABLE STRUCTURES
• Non-rigid, flexible cables shaped in a
certain manner and fixed at the ends to
span the space.
• A cable subject to external loads will deform
depending upon the magnitude and location of the
external forces. This forms a Funicular Shape
through the stresses.
6. • Cable sag: The vertical distance between the supports and the lowest point in the cable (f).
• Without sag - cable cannot carry the load - tensile forces are horizontal ( do not balance vertical load)
Funicular shapes changing
with position of point load.
• A critical problem in the design – dynamic effect of wind - undesirable fluttering of the roof.
• Ways to combat flutter
1. Additional permanent load
2. Rigid members acting as beams
Cable sag due to
single point load
Cable sag due to
multiple point loads
Cable sag due to
uniformly distributed
load
Suction pressure
Internal positive
pressure
7. • Cables are attached to deck and the
compression members.
• Only one set of cables are used.
• Good for medium spans
• Stiffer than suspension bridge
• Less expensive than suspension bridges
• Suspension cables are stretched across
the compression members and vertical
cables support the deck.
• 2 sets of cables are used.
• Good for long spans (eg: across rivers)
• More flexible than cable stayed
• Expensive compared to cable stayed.
TYPES OF CABLE BRIDGES
8. • Span- 620 ft ( 188m) along major axis and 513ft
(156 m) along minor axis.
• The longest suspension roof- span 163 m. (535 ft.).• Today the longest suspension
bridge - span 1410 m. (4226 ft.)
Akashi kaikyo bridge, Japan
• The earliest use of cables - 70 AD.
• A roof of a roman amphitheater - rope cable
structure.
The Burgo Paper Mill in Mantcia
9. 1. UNIVERSITY DISTRICT GATEWAY BRIDGE
• Location: Spokane,
USA
• Architects: LMN
Architects
• Year: 2018
View of the bridgeArch taking compression
Stout connectors Load diagram
• 450-ft ( 137 m) span
bridge
• inspired by traditional
railyard bridges
• 120-ft (36.5 m) tall
concrete arch.
• Deck - suspended using
thick steel cables and
stout connectors.
Bird’s eye view View of bridge from below
• Cable stayed system
10. 2. GOLDEN GATE BRIDGE, SAN FRANCISCO
• Location: San
Francisco, USA
• Engineer : Joseph
Baermann Strauss
• Year: 1933 -1937
View of the bridgeView from deck of bridge
Load diagram
• The main span,1,280
m (4,200 ft).
• suspended from two
cables hung from
towers 227 m (746
ft) high
• Each of the 2 cables
are made up of
27,572 strands of
wire. (128,747 km)
Bridge from the ground Construction of bridge
• Suspended system
11. 3. DULLES INTERNATIONAL AIRPORT
• Architect : Eero
Saarinen.
• Location: Chantilly,
United States
• Year of project
completion : 1962.
View of Dulles airport
Slanted concrete members Side elevation depicting curved roof
• Rectangular floor
plan
• Span - 590 ft (180 m)
• Width - 164 ft(50 m).
simply suspended cable
roof system - forms a
sweeping curved roof
12. • Steel suspension cables span - 164 feet width - anchored to slanted RCC piers (10 feet interval.)
Cable system holding the
roof in place
Cables- exert vertical and horizontal forces on columns
vertical forces -
compression in piers.
horizontal forces - resisted
by stiff concrete cladding
(for roof). (prevents
horizontal deflection )
• Columns (at an angle) - balance moment created by the horizontal pull of the cables through dead load.
Load diagramInterior view of columns
13.
14. TENT STRUCTURES
DEFINITION : Tent or tensile structures is the term used to refer
to the construction of roofs using a membrane held in place on
steel cables.
Work under tensile stress
Ease of pre-fabrication
Cover large spans
Malleable
INTRODUCTION
CHARACTERISTICS
CLASSIFICATIONS IN THE FIELD OF TENSILE CONSTRUCTION SYSTEMS
Membrane tensioned Mesh tensioned
Membrane is held by
cables, allowing the
distribution of the
tensile stresses through
its own form.
Structures in which
mesh of cables carries
the intrinsic forces,
transmitting them to
separate elements.
CONICAL FORM
HYPER FORM
SADDLE SHAPED
15. Structurally, the system is formalized by combining three
elements: membranes, rigid structures such as pole and masts
and cables.
INTRODUCTION
CABLES MEMBRANE
POLES/MASTS
PARTS OF A TENT STRUCTURE AND THE FORCES THEY UNDERGO
LOAD TRANSFER IN DIFFERENT FORMS
ConicalWaveHyper
POINTS OF APPLICATION OF TENSION
Tensile structures only carry tension and are commonly
used as roofs or canopies.
Different arrangement and direction of fabric warps
produce different strength values.
Need pre-tensioning to reduce the deflection of the loaded
membrane and to increase the stiffness of the membrane.
16. BERBER TENTS IN THE SAHARA TEEPEES OF THE AMERICAN TRIBES
CIRCUS TENTS IN THE OLDEN TIMESTENTS OF THE ROMAN TROOPS
HISTORY OF TENT STRUCTURES:
The first man-made
shelters, such as the
b l a c k t e n t s
d eve l o p e d u s i n g
camel leather by the
n o m a d s o f t h e
Sahara Desert, Saudi
Arabia and Iran.
Structures used by Native
American tribes.
Tensile structures
are based on the old
systems used during
the Roman Period,
but there were only
a few technological
advances.
It was only after the
Industrial Revolution
and the triggering of the
era of Fordism that new
developments were
able to meet the needs
of this construction
system. Eg. Circus tents
17. DIPLOMATIC CLUB HEART TENT ARCTIC CITY
HALL AT THE INTERNATIONAL GARDEN EXHIBITION
INTERNATIONAL AND UNIVERSAL EXPOSITION, MONTREAL MUNICH ZOO AVIARY
UMBRELLAS FOR PINK FLOYD’S CONCERT TOUR
WORKSOFFREIOTTO
CONTRIBUTION OF FREI OTTO:
Frei Otto is a German architect and engineer who since the 1950s conducted
the first scientific studies and the first works of roofing using tensioned steel
cables combined with membranes.
As a student, Otto visited the office of Fred
Severud, where he saw the Raleigh Arena in
North Carolina and was impressed by the bold
aesthetics of the project.
He then began to explore small scale physical
models, empirically generating several surfaces,
by means of chains, pulled cables and elastic
membranes.
FREI OTTO’S “THINKING IN MODELS” EXHBITION IN KARLSRUHE,
GERMANY
Convinced by the
u s e f u l n e s s o f
tensioned roofs, he
developed various
projects.
18. TYPES OF TENT STRUCTURES:
TYPE FORM DESCRIPTION EXAMPLES
1. SADDLE ROOF
Four or more point system
when the fabric is stretched
between a set of alternating
and low points.
2. MAST SUPPORTED
Structures typically have one
or sometimes more peaks
supported either by interior
or perimeter masts.
3. ARCH SUPPORTED
C u r v e d c o m p r e s s i o n
members are used as the
main supporting elements
and cross arches are used
for lateral stability.
4. COMBINATION
It consists of combinations
of several support systems
during construction.
PERIMETER MASTS INTERIOR MASTS
19. CONSTRUCTION STAGES OF THE HYPERBOLIC PARABOLOID FORM
1. ERECTION OF END SUPPORTS 4. LAYING OF THE MEMBRANE
5. FIXING AND TENSIONING OF THE MEMBRANE
3. TYING OF THE CABLES2. ERECTION OF INTERMEDIATE SUPPORTS
20. STRUCTURAL DETAILS
TENSIONING OF THE MEMBRANE
FIXING OF THE CABLES AND SUPPORTS
CENTENARY CABLE FIXING DETAILS
CABLE CLAMP DETAIL
21. 1. DENVER INTERNATIONAL AIRPORT
• LOCATION : Northeast Denver, Colorado
• SITE AREA : 140 sq.km
• ELEVATION : 1655 m
• LENGTH : 3200 m
• WIDTH : 46 m
• RUNWAYS : 6
• YEAR : 28 February, 1995
• PROJECT BY : Curtis W. Fentress DENVER INTERNATIONAL AIRPORT OVERVIEW OF THE AIRPORT
3KM LONG STRETCH OF TENTS
DETAILS
1. ROOF STRUCTURE IN TEFLON WOVEN FIBRE
2. ROOF RESEMBLES SNOWY PEAKS OF ROCKY
MOUNTAINS
3. TENT STRUCTURE TO OVERCOME STRONG
WINDS
4. VOLUME – STEEL, GLASS, CONCRETE
5. COMPLEX TECHNOLOGY USED FOR THE
STYLISTIC FACADE
THERMAL GLASS WALLS FOR COMFORTABLE COMMUTE WITHIN
22. 1. DENVER INTERNATIONAL AIRPORT
Due to the Teflon material, 90% of the sunlight gets reflected without conducting heat
INTERIOR OF THE AIRPORT STRUCTURE RESEMBLES AN “ENCAMPMENT”
TENSION TENSION
COMPRESSION
WOVEN TEFLON FIBRE ROOF MEMBRANE
23. 2. MUNICH OLYMPIC STADIUM
• LOCATION : Munich, Germany
• ARCHITECT : Gunther Behnisch, Frei Otto
• ENGINEER : Frei Otto
• LENGTH : 108 m
• WIDTH : 68 m
• YEAR : 1968 - 1972
OVERVIEW OF THE MUNICH OLYMPIC STADIUM RHYTHMIC ELEVATIONS MIMICKING THE ALPS
T
T
CCC
C
SECTION OF THE MUNICH OLYMPIC STADIUM
• DETAILS:
i. The structure had a continuous flow along the
site mimicking the draping and the rhythmic
elevations of the Swiss Alps.
ii. It took large pipes and steel cables to lift and
keep in the air the structure on which the
canopy would be supported.
iii. 65 to 400 metres long cables.
iv. The high precision allowed easy assembly for
one of the most innovative and complex
structural systems that have been worked only
with the premise of stress.
24. 2. MUNICH OLYMPIC STADIUM
SPECIFICATIONS
1. AREA COVERED – 74000 SQ.M
2. ENCLOSURE – PVC COATED POLYESTER, 2.9 X 2.9 M, 4MM THK
3. CABLES – EDGE LACES CLOSED
4. MAST – STEEL TUBES
5. STRAPS / TENDONS – PARALLEL CORDS
6. KNOTS AND CAST STEEL CLAMPS
7. ACRYLIC (PLEXIGLAS) – COVER GLASS
MEMBRANE ELEMENT – 75 X 75 CMSTEEL TUBE MASTS STRETCHING OF THE MEMBRANE
TENT STRUCTURES IN PLAN
25.
26. ARCHED SYSTEM
ARCHED STRUCTURE - A STEEL BRIDGE
DEFINITION : An Arch is a curved structure
designed to carry loads across the gap mainly by
compression.
The Geometry or the Form of the curve might
increase the cost of the structure but decreases the
stresses efficiently.
In Masonry design, the arch is heavy and loaded by
weight of walls. The shape is generally funicular of
the dead load and bending is introduced by live
loads.
In Steel structures, the live load is more and
introduces a large amount of bending.
27. THREE HINGED ARCH TWO HINGED ARCH FIXED END ARCH
Arches used in structures can be Three
Hinged, Two Hinged or Fixed.
The presence of Hinges is very important
when supports, settlements and thermal
expansions are considered.
29. Contributions of ROBERT MAILLART
• Swiss Structural Engineer and Entrepreneur.
• Known for his early 20th century Arch Bridges with a
revolutionary concept of aesthetics.
• Built his first Bridge, at Zuoz, Switzerland in 1901.
• Based on an Integration of Arch & Roadway, Stiffening
the Girder, Adding Aesthetic appeal and large Economic
Savings.
• Famous Curving Schwandbach Bridge, at Schwarzenburg
is described as “A work of art in Modern Engineering.”
• Built many other structures, including a number of
factories and warehouses in Russia between 1912 and
1919.
SCHWANDBACH BRIDGE
ROBERT MAILLART SALGINATOBEL BRIDGE
ROMAN AQUEDUCTS
• Rather than building extremely large arches,
or very tall supporting columns, a series of
arched structures were built one atop
another, with wider structures at the base.
• They were not as stable as occurrence of
tension, torsion or lateral forces is not
resisted by gravity based masonary.
AQUEDUCTS
30. LOAD TRANSFER IN ARCHES
• Arch is a pure Compression as Tension is negligible.
• The load is transferred equally onto both the bases through vertical components and goes
the ground. The ground in turn squeezes and pushes back the components, and
eventually ending back to the arch.
• Tie-rods is another method to prevent horizontal force from spreading the arch
foundation.
• The Rise to Span ratio should not be less than 1/8. Lesser rise takes compression but not
tensile load.
The Strength of An arch can be demonstrated using a paper strips as follows:
RISE(A)
SPAN (B)
TIE-RODS
A:B = 1:8
31. SHAPE OF ARCHES
CATENARY ARCH PARABOLIC ARCH
• If the chain is carrying nothing other than
its own weight, the resulting shape is a
"catenary".
• When the structure is being built and the
main cables are attached to the towers,
the curve is a catenary.
• If the chain is like a suspended cable
carrying a deck below it, and its own
weight is nothing compared to that of the
deck, the resulting shape is a "parabola".
• The curve of the cable in a suspension
bridge is a parabola
A freely suspended chain
In Golden Gate Suspension Bridge, the
suspended cable forms a parabolic curve
as it is held by hangers.Parabolic Curve
Catenary Curve
Simple suspension bridges
32. Reversal of CATENARY ARCHES
• The ‘inverted catenary’ or ‘reversal of caternary arches’
is the approximate optimum form of an arch under its
own weight.
• The greater the height, the lower the horizontal force
in the built at ends and in the middle of the arch.
• The slenderest arches are the ones with lower lateral
force acting on them.
Gateway Arch bridge- An example
of Inverted Caternary Arch
Inverted Caternary Arches
Contributions by ANTONI GAUDI
• Gaudi used catenary arches in many of his projects.
• The advantage of the catenary arch is that it can be
constructed from relatively light materials while still
being able to support great weights.
• Gaudi used hyperboloid structures in later designs of
the Sagrada Familia
Caternary arches at casa mila
Hyperbolic arch in the
interiors of Sagrada Familia
33. 1. COMMUNITY CENTRE OF SAURASHTRA UNIVERSITY - RAJKOT
LOCATION : Rajkot, India
ARCH MATERIAL : Concrete
ARCH SPAN : 47m
TYPE : Fixed End Arch
• Comprises of Three large span (47 m) Concrete arches was conceived.
• The arch starts from ground itself at both ends.
• Span at foundation level is 47.2 m
• Span at ground level is 40.47 m.
• The main system supporting the whole structure is composed of three large
span arches which covers 50 m x 11m column free area.
GOOD QUALITY ROCK WAS USED TO RESIST
HORIZONTAL THRUST BY ARCH AT THE SUPPORT
ARCH SECTION IS 0.45 M X 0.75 M.
CENTRAL RISE ABOVE GROUND IS
5.95 M.
FULL UTILIZATION OF COMPRESSIVE
STRENGTH OF CONCRETE IN THE ARCH
34. 2. ZDAKOV BRIDGE
COMPLETION : 1965
STRUCTURE : Two-hinged Arch Bridge Deck Arch Bridge
LOCATION : Písek District, Czech Republic
ARCH SPAN : 330 M
SPAN LENGTH : 2 × 23.4 M - 2 × 26.0 M - 330.0 M
MATERIAL : Steel and Concrete
ARCHITECT : František Faltus
• At that time, the world's largest steel plate-girder
arch was used in the project when build in the mid-
1960.
• The bridge was originally constructed as a three
hinged.
• After connecting, the two halves and fixing the
central hinge, the arch worked for transport loading
as a Two Hinged bridge.
• Bridge Deck consists of Two continuous steel beams
of composite steel and Concrete transversal girders.
ZDAKOV BRIDGE, CZECH REPUBLIC
BRIDGE DECK
ARCH FIXING STEEL GIRDER
35. (Composite structure – Arched + Vector Active)
LOCATION : Paris
ARCH MATERIAL : cast iron
ARCH SPAN : 73m
TYPE : Three Pin Hinged arch
ARCHITECTS : Blavette, Deglane and Eugene Henard
3. Galerie Des Machines - Paris
GALERIE DES MACHINE
MOUNTING THE IRON BEAM
Front Elevation INSIDE VIEW, 1889
• Span of 115 metres (377 ft) and height of 45 metres (148 ft).
• Proportions of the structure were unfamiliar to people who were accustomed to heavy
stone arches.
• The Small Trusses at the base and Larger higher up and light and narrow.
• Free of internal supports.
• Framework consisted of twenty trusses, developed for bridge building
Points of the Three-Pinned
arch
36.
37. PNEUMATIC STRUCTURES
DEFINITION : The Pneumatic Structure is a
membrane that carries load developed by tensile
stresses by introducing air pressure.
Membrane structure that are stabilized by pressure
compression of air
The pressure should be uniformly distributed for
structural integrity.
Pressure difference between the enclosed space
and the exterior are responsible for giving the
building its shape and its stability.
Round in shape greatest volume for least amount
of material.
38. TYPES OF PNEUMATIC STRUCTURES
AIR APPLIED AIR SUPPORTED
By applying an
external force which
pulls up the
membrane.
By providing constant internal
pressure allowing maximum number
of openings. Air is sandwiched
between two membranes.
39. PRINCIPLES FOR PNEUMATIC STRUCTURES
Use of relatively thin membrane supported by pressure difference.
Membrane can support both tension and compression and thus withstand bending
moment.
Air is introduced till a point till the membrane materials reaches maximum elasticity to
give an even shape to the structure.
The pressure difference between the internal and the external is responsible for the
overall shape.
40. AIR INFLATED STRUCTURES
• Supported by pressurized air contained
within inflated structural element with
air sandwiched, between membrane
material .
• Supported frame lies under high
pressure keeping the structure erect.
• The pressure in the structure is same as
the pressure outside the structure.
• There is no restriction of the number
and size of openings.
• It supports itself with potential to
support itself to the ground.
41. AIR SUPPORTED STRUCTURES
• It is a single membrane with a
small internal pressure difference
with greater internal pressure
• Air must be constantly provided
blown by blowers to maintain
constant pressure
• Overall lifespan of 20 to 25 years
making it ideal for a temporary
structure.
• They are either anchored to the
ground with the help of cables or
they are attached to the walls
42. COMPONENTS OF A PNEUMATIC STRUCTURE
• Envelope
• Materials are seemed together by
sealing , heating or mechanically
jointing.
• The design of the membrane spread
depends on evenly pressurized
environment derived by various
softwares.
• Fiber glass ,Polyester ,Nylon are few
membrane materials used for these
structures.
• Cable system
• They act as support system holding the
structure down to the ground
• They are majorly used in temporary
pneumatic structures
NYLON POLYESTERFIBER GLASS
SECTIONAL VIEW
43. COMPONENTS OF A PNEUMATIC STRUCTURE
• Pumping equipment
• Used to supply and maintain internal pressure.
• Fans, blowers or compressors for constant
supply
• Amount of air required depends on the weight
of the material and wind pressure.
• Doors
• single , double or even revolving door may be
used
• Foundation
• Structures are used to anchorage themselves by
using heavy weights for a temporary use.
• Heavy weight structure anchor by using a
foundation provided with RCC cables.
• When anchorage is done to the soil , the cable is
attached to the anchor directly inserted and
frictional forces of the soil to hold it down.
• For dependent structure, the envelope is
anchored to the main structure.
BLOWER AND A COMPRESSOR
PLACEMENT OF BLOWER
44. 1. U.S. PAVILLION, 1970 WORLD EXPOSITION
• LOCATION :Osaka, Japan.
• ARCHITECT :Davis Brody Bond.
• YEAR : 1970
• The U.S. Pavilion at EXPO features one of the first air supported cable roofs. Super-elliptical in shape and spanning 262 x 460 ft., the
roof employs cables 20 feet on center and arrayed in a diamond pattern. Cables are anchored to a concrete compression ring resting
on, but not anchored to, an earth berm. The berm’s shallow slope and the roof’s flat dome (23 ft rise) greatly reduces wind loading.
An enormous elliptical crater covered by what is the largest clear-span air-supported cable & roof covering 100,000 sq Ft.
• Made of translucent, vinyl-coated fiberglass, the roof filtered natural light by day and glowed at night. A steel cable net provided a
construction armature and secondary support.
AIR STRUCTURED ROOFENTRANCE TO THE PAVILLION BIRD EYE VIEW
45. AIR VENTS
SECTION OF AIR FLOW
DETAIL OF JOINERY OF THE STEEL CABLES
AND SKIN MEMBRANE
DETAIL OF JOINERY OF THE STEEL CABLE TO THE CONC. WALL
1. U.S. PAVILLION, 1970 WORLD EXPOSITION
46. 2. TOKYO STADIUM
• LOCATION :Bunkyo City, Tokyo 112-0004, Japan
• ARCHITECT: Takenaka corporation, Nikken Sekkei
• SITE AREA : 112,456 m2 (27.788 acres)
• PROJECT AREA : 46,755 m2 (503,270 sq. ft.)
• HEIGHT: 56 m
• CAPACITY : 57,000
• YEAR OF COMPLETION :1988
• STRUCTURAL SYSTEM:
i. The membrane roof is made up of glass fiber
membrane materials coated with fluoropolymers,
which was created specifically for Tokyo Dome.
ii. It is supported by 28 cables and the total weight
amounts to 400 tons.
TOKYO STADIUM
AIR STRUCTURE PNEUMATIC SYSTEM
47. 2. TOKYO STADIUM
• On June 28th, 1987, the roof was lifted up (putting air inside Tokyo Dome and inflating the roof).
5:30 a.m.
Mild wind blowing in early
morning. Air sent, decreasing
Internal pressure.
6:25 a.m.
Membrane inflating
from the peripheries
to central.
8:03 a.m.
The roof successfully reaches
the targeted height, and the
process is done.
It took about 2 and a half hours.
• The membranes are two-layered, and the thickness of the inside layer is 0.35 mm and that of the outside 0.8
mm, which are so thin that about 5 percent of the sunlight goes through them.
• Pressurized ventilation fans send air in the stadium so that the air pressure inside is 0.3 percent higher than
that of outside, which supports the membrane roof.
• A total of 36 fans are situated in the highest area of stands, surrounding Tokyo Dome.
48. FORM ACTIVE STRUCTURES AS SUPPORT SYSTEM
La Casa Sobre - Amanico Williams Sagrada Familia Interiors Palazzo Dei Congressi- Louis Kahn
La Casa Sobre - Amanico Williams
Sections of La Casa Sobre
