Bridge Bearings has been considered as of huge importance in civil engineering. It plays a significant role in the structure of bridges. This presentation covers the complete study of Bridge Bearings.

1. Study of Bridge Bearings
Presented By : Ayush N. Hajare
( Diploma student, 2nd year, civil
engineering)

2. Contents
• Introduction of Bridge Bearings
• History of Bridge Bearings
• Function of Bridge Bearings
• Types of Bridge Bearings
• Forces on Bridge Bearings
• Movements on Bridge Bearings
• Some Bridge Projects in India
• Conclusion
• References
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3. Introduction of Bridge
Bearings
• A bridge bearing is a component of a bridge which
typically provides a resting surface between
bridges piers and bridges deck.
• The purpose of bearing is to allow controlled
movements and thereby reduce the stress
involved.
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4. History of Bridge Bearings
• The first bridge bearing to be used were plne
bearings in early 1800s , which included sliding
bearing or roller bearings.
• In mid- 1900s deformation bearings began to be
used, which were made of rubber.
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5. Function of Bridge Bearings
• A bridge bearing carries loads or
movements in both vertical and
horizontal direction from bridge
superstructure and transfer those
loads to bridge piers and
abutments.
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6. @ayushhajare

7. Types of Bridge Bearings
• Sliding bearing
• Rocker and pin bearing
• Roller bearing
• Elastomeric bearing
• Curved bearing
• Pot bearing
• Disk bearing
Bridge bearing
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8. 1.Sliding bearing
• Sliding bearing consists of two metals plates, commonly
stainless steel plates, that slide relative to each other,
hence makes room for translation movement and
lubricating material between them as illustrated.
• A friction force is generated in sliding bearing and it is
imposed on substructure and superstructure and sliding
bearing itself.
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9. • It may be required to provide lubricant such as
polytetrafluoroethylene (PTEE) to decline
generated friction.
• It is specified by ASSHTO that sliding bearing
cannot be used unless the bridge span is smaller
than 15m.
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10. •What is ASSHTO?
• The American Association of State Highway and
Transportation Officials (AASHTO) is a standards
setting body which publishes specifications, test
protocols, and guidelines that are used in highway
design and construction throughout the United
States. Despite its name, the association represents
not only highways but air, rail, water, and public
transportation as well.[4]
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11. 2.Rocker and pin bearing
• Rocker is an expansion bearing composed of curved surface at
bottom , which accommodate translation movement and pin at
top makes room for rotation movement as illustrated.
• Pin bearing is fixed bearing that make room for rotation
movement through the application of steel pin.
• Pin bearing has similar structure and component like rocker
bearing apart from bottom of pin bearing which is flat and fixed
to concrete piers.
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12. • Both rocker and pin bearing are mainly employed in
steel bridge structure.
• Rocker and pin beay should be considered when
bridge movement is adequately known and described
, since such bearing make rooms for both translation
and rotation movements in one direction only.
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13. 3.Roller bearing
• Roller bearing can be used in construction of
reinforced concrete and steel bridge structure.
• There are two main structures including single
roller bearing which is composed of one roller
placed between two consists of several rollers
installed between two plates.
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14. • The former can accommodate both rotation and
translation movement in longitudinal direction and it is
cheap to manufacture.
• In contrary, can make room for translation movement
only and rotation movement can be accommodate if
rollers are combined with pin bearing.
• Multiple roller bearing are expensive and support
considerably large vertical loads.
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15. 4.Elastomeric bearing
• It consists of elactomer manufactured from synthetic or
natural rubber and can take both translation and rotation
movements through elastomer deformation.
• The ability of elastomer to carry large vertical loads is
because of reinforcement provision that prevents lateral
builging of elastomer.
• There are number of elastomeric bearing pads classified
based on types of reinforcements used.
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16. • For example, steel reinforced, pliin, fiberglass
reinforced and cotton duck reinforced elastomeric
bearing pads.
• Strength and response of each type is different , steel
reinforced elastomeric bearing is the strongest one and
plain elastomeric pad is the weakest.
• Elastomeric bearing is niether expensive nor requires
considerable maintenance, that iswhy it the most
desired bearing type.
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17. 5.Curved bearing
• It consists two curved plate that match each other
, if curved bearing is cylindrical, then it only
accommodate rotation movements.
• Both rotation and translation movements can be
dealt with if curved bearing is spherical.
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18. 6.Pot bearing
• Pot bearing consists of elastomeric disk confined
in a pot , steel and piston that is properly tailored
into a pot wall and flat sealing rings which keeps
elastic inside the pot.
• Pot bearing can support considerable vertical
loads and it is commonly transferred through steel
piston to the elastomeric disc which is almost
incompressible.
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19. • As far as lateral load is concerned , it is transferred
as steel pistol moves toward pot wall.
• Translation movement is limited in pure pot
bearing that is why PTEE are introduced to sliding
surface to make rooms for translation movements.
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20. 7.Disk bearing
• Different components of disk bearing are
shown,rotation movement is accommodated
through the deformation of elastomer whereas
the translation movement is considered through
the application of PTEE slider.
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21. Forces on bridge bearings
•Self-Weight
•Traffic loads
• Wind loads
• Earthquake loads
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22. Movements on bridge bearings
• Translation (both transverse and longitudinal
directions) caused by creep, shrinkage and
temperature effects.
• Rotations caused by Traffic loading ,
construction tolerances and uneven settlement
of the foundation.
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23. Some projects in India
Dhola Sadiya Bridge
The bridge. Spans the Lohit River , a major tributary
of the Bramhaputra River, from the village of Dhola
( Tinsukia District) in the south to Sadiya to the
north. The bridge is the first permanent road
connection between the northern Assam and
eastern Arunachal Pradesh.
. Total length - 9.15km(5.69mi)
. Width - 12.9m(42ft)
Longest span - 50 m(160ft)
No. Of span - 183
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24. Dhola Sadiya Bridge
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25. List of bridges in India
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26. References
• Lee, David J. (1994). Bridge Bearings and Expansion
Joints. Taylor & Francis Group. pp. 4–5. ISBN 0-419-
14570-2.
• Gilstad Drew E. (1990-05-01). "Bridge Bearings and
Stability". Journal of Structural Engineering. 116 (5):
1269–1277. doi:10.1061/(ASCE)0733-
9445(1990)116:5(1269).
• Brinckerhoff, Parsons (1993). Silano, Louis G. (ed.).
Bridge Inspection and Rehabilitation: A Practical Guide.
John Wiley & Sons. p. 183. ISBN 0471532622.
• Fu, Gongkang (2013). Bridge Design and Evaluation:
LRFD and LRFR. John Wiley & Sons. p. 304. ISBN
1118332687.
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27. Conclusion
•Hence, these are various types of
Bridge bearings as classified.Also
some big bridges in India like 'Dhola
Sadiya Bridge' on Bramhaputra
River is one of the biggest project in
India.
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28. Thank
you
@ayushhajare