surface active systems
TRANSCRIPT
SURFACE ACTIVE SYSTEMS
Folded Plate Structure
Shell Structure
Barrel Vault
Dome
HYPERBOLIC PARABOLOID
PRESENTED BY- ANUJA MNAHID SPOONAM TPURVA RANKITA GPAYAL CRISHIKESH KDHAMMJYOTIROHAN SPOONAM T
FOLDED PLATES STRUCTURES
They are assemblies of flat plates, or slabs,
inclined in different directions and joined along
their longitudinal edges.
It is capable of carrying loads without the need
for additional supporting beams along mutual
edges.
Uses:
to construct roofs for industrial
warehouses and public buildings.
Material used:
cast in situ or precast reinforced concrete,
or steel plate.
Simple formwork required, and usually use less
material.
They have an intrinsic rigidity and high load-
carrying capacity which makes them
economical over long spans.
Fig.1
Fig.2
The Principle of Folding
The structural characteristics of folding structures depend on-
The pattern of the folding.
Their geometrical basic shape.
Its material.
The connection of the different folding plates.
The design of the bearings.
The Basic concept of Folding
Fig.3 Fig.4
Structural Behavior of Folding
Structural Condition Of Folding Structures.
Load Distribution process :
At first, the external
forces are transferred to
the shorter edge of one
folding element.
There, the reaction as an
axial force is divided
between the adjacent
elements.
Then the forces
transferred to the
bearings.
Types of Folded Structure
Based on geometric shape folded structures
can be divided into:
Folded plate frames structures
Folded plate surfaces structures
folded plate structuresFig.5
Fig.6 Fig.7
Types of Folded Structure
Classification of folded structures based on
the material they are made of:
Folded structures made of reinforced
concrete
Metal folded structures
Folded structures of wood
Folded structures of glass
Folded constructions made in
combination
of different materials
Fig.8
Fig.9
ADVANTAGES AND DISADVANTAGES OF FOLDED-PLATE
STRUCTURE
Advantages:
Very light form of construction. To span 30 m shell thickness
required is 60 mm only.
The use of concrete as a building material reduces both
materials cost and a construction cost.
Longer span can be provided.
Flat shapes by choosing certain arched shapes.
Esthetically it looks good over other forms of construction.
Disadvantages:
Shuttering is difficult.
Greater accuracy in formwork is required.
Good labor and supervision necessary.
Rise of roof may be a disadvantage.
CASE STUDY
Name of structure-Airship Hangars,Orly
(1916-1924)
Engineer-Eugene Freyssinet
He designed two large hangars at orly,each
300 meters long,span-86 meters and over 5
metres high.
It consisted of trough-shaped arches forming
continous barrel vaults in form of a parabola
with arch profile.
The slab forming the troughs was from 80-200
mm thick,increasing towards base.
The stresses were taken by foundations.
The strength created by folded plate profile
reduced reinforcement.
Fig. Airship Hangars,orly
THE APPLICATION OF FOLDED STRUCTURES
As Roof Structure As Wall Structure
As Steel Sheet Piles As Floor Structure
Mia
mi M
arin
e S
tad
ium
, Fl
ori
da
Ch
urc
h o
f N
otr
e D
ame
d
e R
oya
n, F
ran
ce
Mez
zan
ine
ceili
ng
calle
d
"Kie
lste
g"
Secu
rin
g Th
e
Fou
nd
atio
n P
it W
ith
La
rsen
Pla
nks
The term “shell” is used to describe the structures which possess strength
and rigidity due to its thin, natural and curved form such as shell of egg, a
nut, human skull, and shell of turtle.
Shell roof shapes divided into 3 parts –
Dome
Vaults
Saddle shapes and conoids
The strength and rigidity of thin,natural,curved shell structures makes its
possible to construct single curved barrel vault 60 thick with
span of 30 m
Material- Reinforced concrete as highly plastic material can take any shape
when mixed with water
Shell structure are sometime described as single or double curvature shells
Single curvature shells- curved on one linear axis
Double curvature shells- either part of sphere as dome or hyperboloid
SHELL STRUCTURE
TYPES OF SHELL ROOF FORMS
Conoid shell Square dome
Hyperboloid of revolution Barrel vault shell roof
ADVANTAGES AND DIS-ADVANTAGES OF SHELLS
ADVANTAGES-
Very light form of construction. To span 30.0 m shell thickness required is
60mm
Dead load can be reduced economizing foundation and supporting system
They further take advantage of the fact that arch shapes can span longer
Flat shapes by choosing certain arched shapes
Esthetically it looks good over other forms of construction
DISADVANTAGES -
Shuttering problem
Greater accuracy in formwork is required
Good labor and supervision necessary
Rise of roof may be a disadvantage
CASE STUDY – OPERA HOUSE
Location – Australia.1959-1973
Architect- Jon unzone
Span –49.987 m
Height -65m
Materials-
Actual clay, brick, and stone veneer
Granite or marble cladding
Exposed aggregate finish
Sand blasted finish
Form liner patterns
White glazed granite tiles. 1,056,000 tiles were used to cover the massive structure.
Fig :Plan Fig :Framing
Fig :Sydney opera house steel reinforcing fig :Use of tiles
Fig :Sydney opera house shell ribs
BARREL VAULT SHELL ROOFS
Construction –
Thin membrane of reinforced
concrete positively curved in
one direction so that the vault
acts as structure and roof
surface.
Thickness- 57-75
Span – 12-30 m
Wall-
Nonloadbearing panel walls of
brick, block or timber built
between or across columns .
Types –
Short span barrel vault
Long span barrel vault
Stiffening of beams and arches –
To avoid distortion of barrel vault
stiffening beam and arches are cast
integrally with the shell.
Down stand beam –
150-225 mm thick more efficient
because of its depth.
Up stand beam – To avoid
interruption of soffit line of vaults.
Arch ribs – less efficient , provided
for appearance
Thermal insulation –
Thin concrete- poor resistance to
transfer heat
Use of insulating soffit lining or light
weight aggregate screed
Edge and valley beams – Due to self weight and imposed loads thin shell will tend to
spread and its curvature flatten out . To resist this reinforced beam are cast between
columns as integral part of shell
Expansion
joint –
To limit expansion
and contraction
continuous
expansion joint is
used at the interval
of 30. Concrete shells are covered with non ferrous shee metal, asphalt, bitumen felt, a plastic membrane
STIFFENING BEAMS AND ARCHES FOR BARREL VAULT
CASE STUDY – EARTH INSTITUTE
Location - Auroville
Founded by HUDCO,Government of India in 1989
Semi- circular vault –
Span- 6m
Length-11m
Thickness- 36.5-7cm
Material- Arches, vaults,domes build with
compressed stabilased earth blocks without using formwork
Construction Technology-
Projection of section of arch in plan.
Vaulted structures are characterized by acoustic phenomena .
Build with free spanning with combination of horizontal and vertical courses.
Vault stability calculated without the weight of waterproofing and applied after
completion of vault which changes the line of thrust in structure.
Fig: semicircular arch
Starting the horizontal courses Laying 3-
5mm mortar
Pressing the block on site
Filling the joints Horizontal courses Starting arch window
Building vertical
courses Casting waterproof
earth plaster
Laying bottom
side blocks of
the window
Completing bottom
side blocks
Window arch
completed
Arch of the window
being build with the
help of reverse
centering
WHAT ARE DOMES ?
DOME, IN ARCHITECTURE, HEMISPHERICAL STRUCTURE EVOLVED
FROM THE ARCH, USUALLY FORMING A CEILING OR ROOF.
A DOME CAN REST UPON A ROTUNDA OR DRUM, AND CAN BE
SUPPORTED BY COLUMNS OR PIERS THAT TRANSITION TO THE DOME
THROUGH SQUINCHES OR PENDENTIVES.
THE MAIN OBJECTIVE OF THE STUDY IS TO DESIGN THE STRUCTURAL
ELEMENTS OF A DOME STRUCTURE SUCH AS SHELL STRUCTURE, RING
BEAM, COLUMN AND FOOTING.
THE SHAPE OF THE DOME ENCLOSES THE MAXIMUM AMOUNT OF
SPACE WITH THE LEAST SURFACE AREA.
Edna, texas Internal view
SOME OF THE TERMINOLOGY THAT IS OFTEN
ASSOCIATED WITH DOMES INCLUDE:
Apex: the uppermost point of a dome (also known as the ‘crown’).
Cupola: a small dome located on a roof or turret.
Extrados: the outer curve of a dome.
Haunch: part of an arch that that lies roughly halfway between the base and the
top.
Intrados: the inner curve of a dome.
Springing: the point from which the dome rises.
TYPES OF DOMES
DOME AND HEMISPHERE
PARABOLIC DOME HYPERBOLIC DOME
TRANSLATIONAL DOME
VIDHAN SABHA , BHOPAL
Location- bhopal 1982-1996 Architect- charles correa Area- 32000m2 Construction technology-
conventional – in –site- reinforced concrete
Material- indian marble,granite.Red sandstone
ROOF PLAN AND SECTION
Section
Plan
THE STATE ASSEMBLY, IN THE CAPITAL CITY OF BHOPAL HAS BEEN DESIGNED BY ARCHITECT CHARLES CORREA FOR THE GOVERNMENT OF MADHYA PRADESH.
THE VIDHAN BHAVAN IS A HUGE BUILDING, COVERING AN AREA OF MORE THAN 32,000 SQ. METERS OF BUILT SPACE.
SPACES IN VIDHAN SABHA
THE UPPER HOUSE – VIDHAN PARISHAD (75 MEMBERS)
THE LOWER HOUSE – VIDHAN SABHA (231 MEMBERS)
THE COMBINED HALL
LIBRARY
THE SPEAKERS OFFICE
THE CHIEF MINISTER OFFICE
THE CHIEF SECRETARY AND SUPPORTING STAFF OFFICE.
THE MINISTERS AND P.A’S OFFICE (70 NOS.)
SERVICES, UTILITIES, AND PARKING FACILITIES
VIDHAN SABHA (LOWER HOUSE)
• THE MAJOR ATTRACTION IS THE ASSEMBLY HALL.
• THE CAPACITY OF HALL IS 231.IT IS CIRCULAR IN
PLAN, HAS 15.5 MTS. RADIUS COVERED BY
HEMISPHERICAL DOME OF DIA. 31.00MTS AND
THICKNESS VARIES FROM 150 TO 90MM THE HEIGHT
OF THE CROWN FROM FLOOR IS 25MTS.
• K-13 CELLULOSE FIBER COATING IN 40 MM
THICKNESS IS USED TO CONTROL THE ECHO IN THE
HALL AND ALSO BROKEN TILES ARE USED ON THE
ROOF FOR HEAT INSULATION
• ACCESS TO THE HALL IS PROVIDED THROUGH THE
GRAND ENTRANCE RESEMBLING TO SANCHI GATE.
• IT IS PAINTED VERY COLORFULLY REPRESENTING
THE PRESENCE OF LORD GANPATI AT ENTRANCE.
CONCRETE HYPERBOLIC PARABOLOID SHELL ROOFS
These can be constructed in reinforced concrete with:-
• minimum shell thickness of 50mm
• Diagonal spans up to 35m
These are cast over a timber form in the shape of required hyperbolic paraboloid
format.
TIMBER HYPERBOLIC PARABOLOID SHELL ROOFS
These are usually constructed using laminated edge beams and layers of t and g bording
to form the shell membrane.
Roofs with plan size
• 6m x 6m - Two layers of boards required
• Above 6m x 6m - Three layers of boards required
CASE STUDY- THE CHURCH OF ST.ALOYSIUS,UNITED STATES
Architect-Erdy McHenry
Architecture
The hyperbolic paraboloid roof is
used most often as an inexpensive
solution to long-span roof
requirements.
It is used for utilitarian purposes
like sports arenas and athletic
facilities.
The tent of St. Aloysius church is
fabricated from standing seam
metal panels.
Fig.4.1
Fig 4.2
Section through Altar Construction of roof
Interior of church Axonometric
To create the overall curve of the building form,a series of
fabricated channels were welded to the 273mm diameter chs top
boom of each truss.
The channels were rotated to varying degrees to suit the orientation
of the planar deck.
A 3mm thick galvanized steel tray was bolted to the top of each
channel and secured with self tapping screws.
Roofing products usedA structural planar deck system
A vapor control layer
160mm glass fiber quilt insulation
Aluminum standing-seam roof covering
CONSTRUCTION DETAILS
REFRENCES
https://www.designingbuildings.co.uk/wiki/Folded_plate_construction
www.novotheatre.gov.bd
www.osanbashi.com/en/outline/features.html
THANK YOU !