Bridge Bearings: Types, Selection Guide & Engineering Considerations - SK Bearings

Bridge Bearings: Types, Selection Guide & Engineering Considerations

What Are Bridge Bearings?

Bridge bearings are structural components installed between a bridge deck and its supports. Their role is to transfer vertical and horizontal loads while allowing controlled movement caused by temperature changes, traffic loading, wind and structural rotation.

Without bearings, these movements create stresses that can lead to cracking, deterioration and costly repairs. Selecting the correct bearing depends on factors such as load, movement, environmental conditions and long-term maintenance requirements.

Types of Bridge Bearings

Elastomeric Bearings

Elastomeric bearings are one of the most common bearing systems used in highway, rail and pedestrian bridges.

Manufactured from reinforced layers of elastomer and steel, they accommodate rotation and moderate movement through controlled deformation. With no moving parts, they provide a reliable, low-maintenance and cost-effective solution for many standard-span structures.

Typical applications

  • Highway bridges
  • Rail bridges
  • Pedestrian bridges
  • Standard-span structures
  • General civil engineering

Cross-section of reinforced elastomeric bridge bearing

Figure 1. Cross-section of an elastomeric bridge bearing showing reinforced elastomer layers bonded to steel plates.

Slide Bearings

Slide bearings are used where greater horizontal movement is required.

They use a low-friction PTFE and stainless-steel sliding surface to accommodate thermal expansion and contraction while safely transferring structural loads. They’re commonly specified for long-span bridges, viaducts and structures exposed to significant temperature variation.

Typical applications

  • Long-span bridges
  • Viaducts
  • Expansion joints
  • High-movement structures
  • Bridges with significant thermal expansion

Cross-section of PTFE slide bridge bearing

Figure 2. Cross-section of a PTFE slide bearing designed to accommodate large horizontal movements.

Other Bridge Bearing Types

Other bridge bearings such as pot bearings, spherical bearings and fixed bearings are used where higher loads, larger rotations or specific movement characteristics are required. These systems are typically specified for larger infrastructure projects following detailed engineering assessment.

How to Select the Right Bridge Bearing

Selecting the correct bridge bearing requires more than matching a load capacity. Engineers must consider how the bridge will move, the environment in which the bearing will operate and the expected design life of the structure.

Example: A standard highway bridge may only require elastomeric bearings because movement is relatively small. By contrast, a long-span viaduct experiencing significant thermal expansion may require slide bearings to accommodate greater horizontal movement.

The checklist below highlights the key factors that should be reviewed during specification.

Bridge bearing specification checklist

Elastomeric vs Slide Bearings

FEATURE ELASTOMERIC BEARINGS SLIDE BEARINGS
Movement Capacity Low to moderate Moderate to high
How Movement Is Accommodated Movement through deformation of reinforced elastomer layers. Movement through a low-friction sliding interface (PTFE and stainless steel).
Maintenance Low maintenance with no moving parts or lubrication requirements. Low maintenance, but PTFE surfaces should be inspected during routine checks.
Typical Applications
  • Highway bridges
  • Rail bridges
  • Pedestrian bridges
  • Standard-span structures
  • General civil engineering
  • Long-span bridges
  • Viaducts
  • Expansion joints
  • High-movement structures
  • Bridges with significant thermal expansion
Key Benefit Reliable, cost-effective solution for standard applications with moderate movement. High movement capacity to accommodate thermal expansion and long-span structural movement.
KEY TAKEAWAY
Elastomeric bearings provide a simple, reliable solution for standard-span bridges with moderate movement. Slide bearings are designed for structures requiring greater horizontal movement. Many bridges use a combination of both bearing types, with each selected to suit the movement requirements at individual supports.

Common Bridge Bearing Specification Errors

Incorrect specification can significantly reduce bearing performance.

Common issues include:

  • Underestimating thermal movement
  • Ignoring support rotation or settlement
  • Failing to consider environmental exposure
  • Over-specifying complex bearing systems where simpler solutions are suitable

Bridge Bearing Inspection and Design Standards

Bridge bearings should be inspected regularly to identify signs of elastomer ageing, PTFE wear, corrosion or restricted movement before these affect the wider structure.

In the UK and Europe, bridge bearings are commonly designed and manufactured in accordance with BS EN 1337, which sets requirements for materials, testing and performance.

Summary

Although relatively small components, bridge bearings play a critical role in protecting bridge structures by safely transferring loads while accommodating movement and rotation.

Whether specifying elastomeric bearings, slide bearings or specialist systems, selecting the correct solution requires careful consideration of structural behaviour, durability and long-term maintenance. Working with an experienced bearing manufacturer helps ensure reliable performance throughout the bridge’s service life.

Bridge Bearing Frequently Asked Questions

What are structural bridge bearings?
Bridge bearings are structural components positioned between a bridge deck and its supports. They transfer loads while allowing controlled movement and rotation caused by factors such as temperature changes, traffic loading and structural movement.
What types of structural bridge bearings does SK Bearings manufacture?
SK Bearings designs and manufactures a range of bridge bearing solutions, including elastomeric bearings, slide bearings and bespoke bearing systems for specific structural, movement and loading requirements.
Can SK Bearings manufacture bespoke bearings?
Yes. SK Bearings can develop bespoke bearing solutions to suit specific structural, movement and loading requirements.
Does SK Bearings provide technical support?
Yes. Our technical team can provide support with bearing selection, design requirements and bespoke applications.

Need help specifying a bridge bearing? Speak to the SK Bearings technical team about your load, movement and application requirements.

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