Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 209

Table 3.28 Brief Comparisons of Commonly Used Bridge Bearings

Capacity
(kN) Type Supply Friction Use Limitations

Pot or disk 500-30,000 Proprietary 0.05 Span > 20 m Rotation

0.01 rad

Elastomeric
laminated

100-1000 Proprietary 0.5-6

kN/mm

Short spans Heavy loads

Cylindrical
roller

1000-1500 Proprietary 0.01 Minimal

friction

Nil lateral
translation
or rotation

Multiple
roller

1000-
10,000

Fabricated 0.25 Roller

bearing/
railway
bridges

High-
friction, nil
lateral
rotation

Line rocker 1000-
10,000

Fabricated 0.25 Hinged

bearing/
railway
bridges

High-
friction, nil
lateral
rotation

Spherical
sliding

1000-
12,000

Proprietary 0.05 Span > 20 m More

expensive
than pot

at their locations. Finally, expansion bearings allow rotations of the sup-
ported structure at their locations and allow translations in particular direc-
tions. Expansion bearings can be sliding, roller, or rocker bearings.
Table 3.28 shows the main types of bearings commonly used in steel bridges.
The most frequently used type of bearing for highway bridges is the propri-
etary pot or disk type, which is able to accommodate rotation and, where
required, lateral movement in either longitudinal or transverse directions
or in both directions. Such bearings are particularly suitable for continuous
and curved bridges. While for railway bridges or footbridges, fabricated line
rocker bearings are often suitable at both ends of bridges. For rail bridges of
span greater than 20 m, fabricated roller/rocker bearings can be used at the
free end. For footbridges, elastomeric bearings are often used.

3.11.2 Examples of Proprietary Bearings
Proprietary pot or disk bearings are commonly used in practice all over the
world. The bearings comprise a circular elastomeric disk confined by a metal
housing (forming a cylinder and piston). The bearings can be combined with