A sliding bearing is a support on which a structural element can move over a smooth sliding surface, so that displacements from temperature, shrinkage or load are accommodated without large horizontal forces arising. The vertical load is transferred, while the horizontal movement is released.
Application
Sliding bearings let a structure ‘breathe’ without cracking or overloading:
- Bridges — the deck expands and contracts with temperature; fixed on one side, on a sliding bearing on the other.
- Precast beams — where a beam rests on a support and must be able to expand.
- Large roofs and floors — at expansion joints where parts may shift relative to each other.
The sliding surface often consists of a layer of PTFE (Teflon) against stainless steel, giving very low friction. The sliding bearing is often combined with a rubber (elastomer) layer that also accommodates small rotations. This absorbs thermal movement and differential settlement without damaging the structure.
Related terms
- Bearing
- Expansion joint
- Bridge
- Structure
- Cantilever
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