Bridge bearings of different types vary greatly in bearing capacity, deformation adaptability, durability and construction cost. It is essential to fully master their structural features, performance advantages and application scenarios before selection, so as to avoid potential engineering hazards caused by improper matching. This article focuses on four mainstream bridge bearing types for in-depth analysis and comparison.
Elastomeric Pad Bearing - Standard Choice for Medium & Small-span Bridges
Structural Features
Made of multiple layers of natural rubber laminated and bonded with thin steel plates. Simple structure without mechanical transmission parts. It is divided into ordinary type and PTFE sliding type, and the latter enables horizontal sliding of bridge girders.
Core Performance
- Vertical bearing capacity: within 1000kN, suitable for medium and small loads
- Deformation capacity: adapts to small rotation angles and minor horizontal displacement
- Advantages: low cost, easy installation, maintenance-free and high cost performance
- Disadvantages: limited bearing capacity, poor low-temperature resistance, prone to aging under large deformation
Application Scope
Highway simply-supported beam bridges with span ≤20m, municipal small bridges, rural highway bridges, and conventional beam bridges with low displacement requirements.
Pot Rubber Bearing - Mainstream Choice for Long-span Bridges
Structural Features
Composed of steel pot base, pressure-bearing rubber block, sealing ring and top cover. It bears vertical force by virtue of incompressibility of confined rubber, adapts to girder rotation via rubber deformation, and realizes horizontal displacement with sliding plates. Classified into fixed type, unidirectional sliding type and bidirectional sliding type.
Core Performance
- Vertical bearing capacity: 1000kN~10000kN, applicable for heavy loads
- Deformation capacity: large rotation angle and wide sliding range, better weather resistance than elastomeric pad bearings
- Advantages: strong bearing capacity, high stability and wide span adaptability
- Disadvantages: higher cost, relatively complex structure, regular inspection on sealing parts required
Application Scope
Continuous beam bridges, prestressed concrete beam bridges, urban viaducts with span of 20-50m, as well as highway-rail dual-purpose bridges under medium loads.
Spherical Bearing - High-end Solution for Complex Bridge Structures
Structural Features
Consists of upper spherical liner, lower spherical base and sliding plate to form spherical hinge structure, realizing arbitrary rotation in three-dimensional space with uniform force transmission and no stress concentration. Available in fixed spherical hinge, unidirectional spherical hinge and bidirectional spherical hinge types.
Core Performance
- Vertical bearing capacity: up to ten-thousand-ton level, suitable for super heavy loads
- Deformation capacity: multi-directional large-angle rotation, fits complex stress conditions
- Advantages: excellent durability, superior seismic and wind resistance, long service life
- Disadvantages: high price, strict processing precision requirements and difficult installation positioning
Application Scope
Large-span arch bridges, cable-stayed bridges, suspension bridges, high-speed railway bridges, sea-crossing bridges and other heavy-duty complex bridges.
Seismic Isolation Bearing - Protective Type for High Seismic Intensity Zones
Main Categories
Friction Pendulum Bearing (FPB), high damping rubber bearing and lead rubber bearing, belonging to special functional bridge bearings.
Core Performance
Besides basic force transmission and displacement adjustment functions, it dissipates seismic energy through friction energy dissipation and elastic damping, blocks seismic force transmission and achieves post-earthquake repositioning, greatly enhancing overall seismic performance of bridges.
Application Scope
Mountainous bridges, sea-crossing bridges, high-speed railway bridges and key traffic hub bridges located in areas with seismic intensity ≥7 degrees.