Classification and Application of Bridge Rubber Bearings

1. Laminated rubber bearing

Laminated rubber bearings are generally used in the use of small bridges. Its structure is simple and easy to install with low cost and a good shock isolation effect, so it is the best choice for small bridge buffer shock isolation. Plate rubber bearings are divided into two categories: ordinary rubber bearings and PTFE plate bearings. Rectangular and circular shapes can also be selected according to different applications.

Ordinary rubber bearings are suitable for bridges with a span of no more than 30 meters and small displacement requirements. They can transmit the reaction force of the upper structure back to the platform, have strong elastic foot stability, and have good seismic effects.

The PTFE plate rubber bearing is coated with 2-3mm polytetrafluoroethylene on the surface of the ordinary rubber bearing, which can increase the vertical load on the basis of the ordinary bearing and can be applied to a small part of the beam end rotation. It can be used in bridges with a span greater than 30 meters and requiring a certain displacement, such as long-span bridges, simply supported girder continuous slab bridges, multi-span continuous girder bridges, and other projects.

2. Pot rubber bearing

The pot rubber bearing is to seal the rubber in the steel structure and generates corresponding reaction force through three-dimensional force. In this way, the built-in rubber block can elastically support the rotation of the beam end, and then the stainless steel plate and coating can slide in a small range to generate horizontal displacement, thereby ensuring the stability and safety of the bridge.

3. Spherical rubber bearing

The spherical rubber bearing is an upgraded version of the pot rubber bearing. It is a special pot rubber bearing composed of an upper bearing plate, a lower bearing plate, a spherical panel, a PTFE slide plate, and a rubber ring. The coefficient of friction is small, and displacement and sliding are more likely to occur, so the shockproof and stable effects are also enhanced.

Spherical rubber bearings have been widely used in continuous curved plate structures supported by single columns, continuous curved box girder structures supported by single columns, continuous T-beam structures supported by double columns and long-span cable-stayed bridges.