Study of Folded Plates for understanding their use, types, technology along with suitable case studies. This is a specific type of Methodology adopted for construction over long spans column free spaces. How structurally Folded plates surpases the need of column grids and conventional methods of construction with the proper design and technology is the motive of this study.

1. FOLDED PLATES
Group Members:
• Rohan.S.Narvekar (37)
• Saurabh.S.Kadam (23)
• Aniket.S.Manjardekar (33)
• Aditya.M.Patil (42)
• Abhijit.D.Nayak (38)
• Alekh.Patil (43)
SUBJECT: THEORY OF STRUCTURES

2. WHAT ARE FOLDED PLATES?
Folded plates are assemblies of flat plates rigidly
connected together along their edges in such a
way that the structural system capable of
carrying loads without the need for additional
supporting beams along mutual edges.
Engineer Eudene Freyssinet performed the first roof with the folded
structure in 1923 as an aircraft hangar at Orly Airport in Paris.
FOLDING SYSTEMS IN NATURE
The principle of folding as a tool to develop a
general structural shape has been known for a
long time. Folded structure systems which are
analogous to several biological systems such as
found at broadleaf-tree leaves, petals and foldable
insect wings, are adopted to be employed in a
new, technical way.
Leaf of Palm Tree Beetle Insect With
Foldable Wings
Seashell

3. 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 planes.
• The design of the bearings.
• Movable form work can be employed.
• Form work required is relatively simpler.
• Design involves simpler calculations.
The Concept Of Stiffness Generation

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.
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 structures of plastic materials
• Folded constructions made in combination of different
materials

5. TYPES OF FOLDED STRUCTURE
Based on geometric shape folded
structures can be divided into:
• Folded plate surfaces structures :
o Prismatic: Rectangular plates.
o Pyramidal: Non-rectangular plates.
o Prismoidal: Triangular or trapezoidal
o plates
• Folded plate frames structures
• Spatial folded plate structures
TAPERED FOLDED PLATES
FOLDED PLATE RIGID FRAMEGEODESIC DOME

6. BASIC ELEMENTS OF FOLDED PLATES:
• The Inclined Plates.
• Edge plates which must be used to stiffen the wide plates,
• Stiffeners to carry the loads to the supports and to hold the plates in line.
• Columns to support the structure in the air.
TAPERED FOLDED PLATES:
• Folded plate structures may be built with tapered elements and only one of the many possible combinations is
shown here.
• The height of the shells at the center of the span is the critical dimension for bending strength. therefore, the
structure is not very efficient and not suitable for long spans because of the excess height required for the large
ends.
• Another weak element in this design is the transfer of shear from the small end of the triangular plate to the large
end. if a large number of units are used in each span, the transfer of loads may be difficult.
• A folded plate may be used for walls as a thin structural element by casting each plate flat on the floor and
grouting the joints full of concrete. a wall of this type can be made much thinner than a flat wall.
T
C

7. FOLDED PLATE TRUSS:
• The term "folded plate truss" is intended to indicate the structural action of this structure.
• There are horizontal ties across the width only at the ends of the building.
• The thrusts from the triangular crossed arches are carried lengthwise to the ends.
• The top chord of the inclined truss is formed by the ridge member.
• The bottom chords are the ties at the base of the side gables and the diagonals are formed by the sloping
valleys at the intersection of the gables and the triangular plates.
• This is truly a space structure and its structural action is as shown and, therefore, the architectural appearance
is mote subtle that the usual shell structure.
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8. FOLDED PLATE RIGID FRAME:
• An arch with straight segments is sometimes called a Rigid Frame.
• It is not as efficient as the curved arch because the bending moments are greater.
• Ties across the plates are required at the knees and at the crown in order to distribute the forces at the ends of
each segment.

9. EDGE SUPPORTED FOLDED PLATES:
• The usual upturned edge plate can be eliminated and the roof structure can be made to appear very thin if the
edge plate is replaced by a series of columns.
• The slab between columns must be designed as a beam and it may be convenient to extend the main roof slab as a
Cantilever Canopy.
• The beam element that carries the load of the roof between columns will then be wider and windows under the
slab will have the same function as in the previous examples of folded plates.
• Note the vertical columns in the end walls at the crown of the gable. these take the reactions of the plates and the
horizontal ties may be eliminated. wind loads are taken by rigid frame action in the Columns and Stiffeners.

10. WALLS CONTINUOUS WITH SHELL:
• In this structure the walls are of tilt-up concrete construction; concrete is cast flat on the floor and raised into
place by cranes.
• The walls are designed to be continuous with the roof plates. Tilt-up walls usually are joined by poured-in-place
columns. in this design, columns are not necessary at the junction of the individual side wall panels because the
walls are braced at the top.
• Only a simple grouted key slot is provided. The tilt-up panels can serve as their own foundation walls so only a
continuous footing pad is used with a notch to receive the tilt-up panel.
• Dock height interior floors can be constructed by filling the interior of the building up with dirt to the required
height.
• The tilt-up walls can be designed for this lateral load because they are held at the top by the shell and act as
vertical beams rather than as Cantilever Retaining.

11. THREE SEGMENT FOLDED PLATE:
• The end stiffeners are rigid frames rather than deep Girders as in the last example.
• The forces from the reactions of the sloping plates on these rigid frames will be quire large and at an outside
column they will not be balanced by thrusts from the adjacent plates.
• The size of the frames may be reduced by using a steel tie between the tops of the columns which can be
concealed in the fenestration. The dimensions of the plates are dependent on both the width of the barrel and
on the span.
• The depth of the shell should be about 0.10 times the span and the maximum slope of a plate should not be
greater than 40 degrees.
• For example, assume for the above structure that the span is 60 feet and the bay width is 24 feet. the depth of
the shell should be about 6 feet and the horizontal width of each plate with a three segment plate should be
about 8 feet.
• 6 the slope of the plates is 6/8, which is about 37 degrees and is satisfactory. the thickness of the plates could
be about 3 ½ inches.

12. THE APPLICATION OF FOLDED STRUCTURES
 As Roof Structure  As Wall Structure
 As Steel Sheet Piles As Floor Structure
Miami Marine Stadium, Florida Church of Notre Dame de Royan, France
Mezzanine ceiling called "Kielsteg" Securing The Foundation Pit With Larsen Planks

13. 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.
• Aesthetically 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.

14. CASE STUDY: AIR FORCE ACADEMY CHAPEL, USA:
• The United States Air Force Academy Cadet Chapel,
completed in 1962, is the distinguishing feature of the
Cadet Area at the United States Air force academy north
of Colorado Springs .
• It was designed by Walter Netsch of Skidmore, Owings
and Merrill of Chicago.
• Construction was accomplished by Robert E. McKee, Inc.,
of Santa Fe, New Mexico. Originally controversial in its
design, the Cadet Chapel has become a classic and highly
regarded example of modernist architecture.
• The Cadet Chapel was awarded the American Institute of
Architects National Twenty-five Year Award in 1996and,
as part of the Cadet Area, was named a U.S. National
Historic Landmark in 2004.
Architecture Construction:
• The most striking aspect of the Chapel is its row of
seventeen spires. The original design called for twenty-
one spires, but this number was reduced due to budget
issues.
• The structure is a tubular steel frame of 100
identical tetrahedrons, each 75 feet (23 m) long, weighing
five tons, and enclosed with Aluminium panels.
Architect: Walter Netsch,
Length: 280 ft, Height: 150 ft, Width: 84 ft,
Year: 1962

15. • The tetrahedrons are spaced a foot apart,
creating gaps in the framework that are
filled with 1-inch-thick (25 mm) coloured
glass.
• The tetrahedrons comprising the spires are
filled by triangular Aluminium panels, while
the tetrahedrons between the spires are
filled with a mosaic of Coloured glass in
Aluminium frame.
• The Cadet Chapel itself is 150 feet (46 m)
high, 280 feet (85 m) long, and 84 feet
(26 m) wide. The front façade, on the south,
has a wide granite stairway with steel
railings capped by Aluminium handrails
leading up one story to a landing.
• At the landing is a band of gold anodized
Aluminium doors, and gold anodized
aluminium sheets apparently covering
original windows.

16. CASE STUDY: YOKOHAMA PORT TERMINAL
Architect: Foreign Office Architects
Floor Area: 34,732 m2,
Length: 430m, Height: 15m, Width: 70m
INTRODUCTION
• The steel frame structure was designed with the beautiful
scenery of the port in mind.
• It is a three level facility of a gentle curved form.
• The occupable roof curves back in to form the ceiling of
the level below and then again to form the floor.
• The inside space is barrier free without columns or beams
and the vertical circulation is accomplished through ramps
and elevators.
SITE AND GENERAL
• The major pier possesses the ability to harbour vessels of
varying sizing including the largest passenger ships. The
port has both pedestrian and vehicular connection to the
mainland.
FUNCTIONS –
• Basement- machinery rooms
• First floor- parking
• Second floor- passenger terminal, multi-purpose space
• Roof- roof plaza, visitor’s deck

17. • The terminal is a shed building measuring 412 meters in
length and composed of 27 steel trusses averaging 42.5
meters in span and placed at 16 meter intervals.
• The trusses are joined longitudinally by trussed members
of conventional configuration, and purlins carrying,
either metal cladding or glazing.
• The trusses are carried on concrete piers extending from
the basement parking level through the surface of the
main level.
• The large shed employs a unified form though
repetitive structural units to enclose a single
homogeneous space.
• The transformation yields a complex of spaces that
smoothly incorporates the multiple terminal, civic
and garden programmes within and below its span.

18. FOLDED PLATE HUT-JAPAN:

19. • There are many homeless people.
• Specially during disaster, many people become homeless.
• We can use the concept of folded plate structure to make portable shelter for the homeless
people.
• Significant works on this project is already in progress.
• It is very cheap and easily useable by anyone.
Recover Accordion Shelter Light Weight Emergency Shelter
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20. THANK YOU!...