Supper stressed ribbon bridge

1. STRESSED RIBBON BRIDGES
Ruhi Riaz
1AT12CV046
Dept Of Civil Engineering,
Atria Institute Of Technology.
Under The Guidance Of :
Asst Prof. Pruthvi Sagar

2. 1. INTRODUCTION
2. FORM OF A STRESS RIBBON BRIDGE :
A. SUPERSTRUCTURE
B. SUBSTRUCTURE
C. GROUND CONDITIONS
3. COMPONENTS OF A STRESS RIBBON BRIDGE
4. COMPARISION WITH SIMPLE SUSPENSION BRIDGE
5. CONSTRUCTION TECHNIQUES
6. MODIFIED STRESS RIBBON BRIDGES :
A. STRESS RIBBON BRIDGE STIFFENED BY ARCH
B. STRESS RIBBON BRIDGE STIFFENED BY CABLES
7. ADVANTAGES
8. DISADVANTAGES
9. FAMOUS STRESS RIBBON BRIDGES
10. CONCLUSION
11. REFRENCES
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3. 1. A Stress Ribbon Bridge is a tension
structure, similar to a simple suspension
bridge.
2. Has slightly sagging tensioned cables.
3. The deck segments are prestressed.
4. Made up of reinforced concrete with steel
tensioning cables.
5. Characterized by successive and
complementary smooth curves.
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4.  SUPERSTRUCTURE
1. Deck has precast concrete planks with bearing
tendons.
2. Prestressing tendons.
3. Joints sealed with concrete.
4. Prestressing tendons transfer horizontal
forces.
5. Tendons are encased in ducts.
6. As bending in the deck is low, depth can be
minimize.
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5.  SUBSTRUCTURE
1. Abutments transfer horizontal forces
from deck cables to the ground.
2. Ground anchors are tensioned in 2
stages.
3. Soil pressure, overturning and sliding
has to be checked for
construction.
4. Loads cause changes in
the bending moments
in the deck.
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6.  GROUND CONDITIONS
1. A rock base is ideal.
2. If soil conditions do not permit the use
of anchors, piles can also be used.
3. Combination of anchors and drilled
shafts are used.
4. Battered micropiling is another
alternative.
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7. 7

8. Suspension Bridges :
Cables carry the load.
The span is simple.
The simple suspension span
tends to sway & bounce.
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Stress Ribbon Bridges :
Deck shares axial tension
forces.
Ribbon is stressed in
compression.
The Stress ribbon bridge
does not sway & bounce.

9. After curing of concrete, the bridge is post tensioned.
Concrete is poured in the joints between the planks.
Post tensioning ducts are placed in the bridge.
After Bearing cables are tensioned, precast panels are
suspended via support rods.
Bearing cables are stretched from abutment to abutment.
Abutments and piers are built first.
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10. A. Stress Ribbon Bridges Stiffened By Arches
1. Deck is fixed in the side strut .
2. Self-anchoring system allows reduction in cost of
construction of substructure.
3. Initially Stress ribbon behaves as a two span cable
supported by the saddle.
4. After post tensioning the stress ribbon with
prestressing tendons,
the stress ribbon and arch
behaves as one structure.
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11. B. Stress Ribbon Bridges Stiffened By Cables
1. External bearing cables stiffen the structure.
2. Horizontal movements caused by live load are
eliminated by stoppers.
3. Deck deflections and bending moments are reduced
to zero or very small horizontal movement.
4. An observation platform can be placed at midspan.
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12. Advantages
1. Economical.
2. Aesthetical and almost maintenance free structures.
3. Require minimal quantity of materials.
4. Minimum environmental impact during
construction.
5. Quick and convenient to construct.
6. Allows for long spans with a minimum number of
piers.
7. Piers can be shorter than those required for
suspension bridges.
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13. 1. Large horizontal forces need to be resisted at the abutments.
Remedial Measures :
i. Construction of flexible members close to the supports.
ii. Widening of the deck at the ends.
iii. Providing an arch shape intermediate support.
2. Danger of overturning and oscillations due to high span to
width ratio.
Remedial Measures :
i. Increasing Sag
ii. Proper dynamic analysis
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14. The Phyllis J. Tilley Memorial Bridge
having a main span of 49.5 m,
combining a steel arch and stress
“ribbon”.
Rogue River Bridge, pedestrian
stress ribbon bridge, has a
main span of 84.73 m , USA.
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15. Lake Hodges Bridge has a
main span of 100.9 m, USA.
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Yume Tsuribashi Bridge, 147.6 m
span, Japan.
Sacramento River Trail Bridge,
127.40 m main span, USA.

16.  Stress ribbon bridges are versatile and
adaptable thus can be constructed
instead of Suspension bridges.
 The slender decks are visually pleasing
and enhance the aesthetic view of the
place.
 Post tensioned concrete minimizes
cracking and assures durability.
 A number of areas require aesthetic yet
cost effective pedestrian bridges to be
built.
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17. 1. Strasky, Jiri (2006). "Stress Ribbon and Cable Supported Pedestrian
Bridges" (PDF). Retrieved 2012-10-28.
2. Strasky, Jiri (2005). Stress Ribbon and Cable Supported Pedestrian
Bridges. London: Thomas Telford.
3. https://structurae.net/
4. www.google.co.in
5. Roma Agarwal, (2009) Stress Ribbon Bridges, The structural
Engineer, pp 22-27.
6. Tomas Kulhavy, (1998), Stress Ribbon Bridges Stiffened by Arches or
Cables, 2nd Int’l phd symposium in civil engineering, Budapest.
7. Preliminary design of prestressed concrete stress ribbon bridge by
Diego Cobo del Arco; Ángel C. Aparicio; and Antonio R. MaŕıMember, ASCE.
8. www.wikipedia.com
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18. THANK YOU