BRIDGE 24
It is usually
preferable to construct continuous bridge deck that integrated with pier and
abutment for overall length less than 60m. By doing this the number of
expansion joints and bearings is reduced, and reduces the maintenance problem.
The expansion joints
are usually positioned above a pier or abutment, where the bridge deck is
directly supported by those vertical elements.
The provision of bearings
is dependent of the deck form. For example, launched box girder require
bearings to aid in the launch process. In situ concrete deck can be either
built on bearings, or directly on pier if the deck movement will not induce
large force in pier and abutment.
Guided bearings
can be aligned toward the point of fixity, considering the bridge deck may
expand or contract towards that point. However, excessive transverse movement
at expansion joints may occur.
Good access is
needed for both expansion joints and bearings to ease the maintenance.
Half joints,
hinges and span discontinuities should be avoided as they allow long-term
deflection and affect the deck profile.
Source:
https://www.steelconstruction.info/Bridge_articulation_and_bearing_specification
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