Bearing in bridge construction

1. Name-Satyajit Sahoo
Roll No-171033

2.  Bearing
 Types of bearing
 Movement on bridge bearing
 Maintainace of
Recommendations

3.  Bearings are important elements in large
infrastructures such as bridges, heavy buildings
and high rise buildings, ensuring load transfer,
movement, rotation , vertical or horizontal
restraints as required by the design.

4. Bearing
Fixed Bearing - Allow rotations but restrict
translational movements.
Expansion Bearings - Allow both rotational
and translational movements

5.  Bridge Bearings are structural device positioned between the
bridge superstructure and the substructure.
 Their principal functions are as follows:
1. To transmit loads from the superstructure to the
substructure
2. To accommodate relative movements between the
superstructure and the substructure.

6.  Translations ( 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 Cracks Bridge
Settlements.

7.  A sliding bearing utilizes one plane metal plate sliding
against another to accommodate translations.
 The sliding bearing surface produces a frictional force that is
applied to the superstructure, the substructure, and the
bearing itself.
 To reduce this friction force, PTFE(Polytetrafluorethylene) is
often used as asliding lubricating material.

8.  Roller bearings are composed of one or more rollers between
two parallel steel plates.
 Single roller bearings can facilitate both rotations and
translations in the longitudinal direction, while a group of
rollers would only accommodate longitudinal translations.

10.  Power-wash steel sliding plates and steel rocker
bearings (especially at abutments) annually when
washing decks. Make sure to concentrate efforts
between rocker surfaces and base plates to remove
dirt that could accumulate and impede movement.
 Touch up steel with high-quality epoxy paint as
needed.
 Neoprene bearings require little maintenance
except occasional power keep dirt and debris from
building up around bearings