March 9, 2026
As bridge engineering has evolved to encompass increasingly complex geometries — skewed alignments, tight horizontal curves, cable-stayed configurations, and long-span continuous structures — the demands placed on structural bearings have grown correspondingly sophisticated. Spherical bridge bearings (also referred to as curved sliding bearings or spherical sliding bearings) have emerged as the premium solution for applications where conventional pot bearings or elastomeric bearings cannot provide the required combination of high load capacity, large rotation accommodation, and multi-directional movement control.
The defining feature of a spherical bearing is its curved sliding interface: a convex stainless steel surface that articulates within a concave PTFE-lined housing. This geometry allows the bearing to accommodate rotation in any direction — a critical capability for bridges where the superstructure may rotate simultaneously about both the transverse and longitudinal axes due to live load, temperature, creep, or differential settlement.
The sliding interface between the polished stainless steel and the PTFE disc provides an extremely low coefficient of friction — typically 0.03–0.06 — enabling the bearing to accommodate horizontal movements with minimal resistance. Unlike pot bearings, where the rotation capacity is limited by the confined rubber disc, spherical bearings can accommodate rotations of up to ±0.05 radians (approximately 2.9°) in any direction, making them suitable for the most geometrically complex bridge configurations.
A large-capacity spherical bridge bearing installed on a concrete pier cap. The polished convex stainless steel surface and the concave PTFE-lined housing are clearly visible. This bearing type is ideal for cable-stayed bridges, curved viaducts, and skewed highway bridges.
Fixed Spherical Bearings accommodate rotation in all directions but prevent horizontal movement in any direction. They are typically located at the point of zero thermal movement on a bridge — usually at one abutment or at a central pier on a long continuous structure.
Free-Sliding Spherical Bearings accommodate both rotation and horizontal movement in all directions. They are used at locations where the superstructure must be free to expand and contract thermally without restraint.
Guided Spherical Bearings accommodate rotation and horizontal movement in one direction only (the guided direction), while restraining movement in the perpendicular direction. They are used to control the direction of thermal expansion and to distribute lateral loads (wind, braking) between supports.
Skewed bridges: When a bridge crosses a waterway or road at an angle, the bearing reactions are not perpendicular to the bridge axis. Spherical bearings can accommodate the resulting combined rotation and translation demands that would overstress a conventional bearing. Curved bridges: Horizontally curved bridges experience complex torsional and out-of-plane bending effects. The multi-directional rotation capacity of spherical bearings is essential for accommodating these movements without inducing unintended restraint forces. Cable-stayed and suspension bridges: The towers and pylons of cable-stayed bridges are subject to significant rotations as the cable forces vary under live load. Railway bridges: High-speed railway bridges impose stringent requirements including high vertical loads, precise movement control, and very low friction.
| Parameter | Typical Range | Notes |
|---|---|---|
| Vertical design load (F_z) | 500 kN – 200,000 kN | Dead load + live load + dynamic effects |
| Horizontal design load (F_xy) | Up to 30% of F_z | Wind, braking, seismic |
| Design rotation (α_d) | ±0.01 – ±0.05 rad | In any direction |
| Design displacement (e_L, e_T) | ±10 – ±500 mm | Thermal + creep + shrinkage |
| PTFE type | Standard / dimpled / woven | Dimpled for lubricated, woven for unlubricated |
| Stainless steel grade | 1.4401 (316) minimum | Polished to Ra ≤ 0.2 μm |
Exploded 3D view of a spherical bridge bearing showing all key components: upper bearing plate, polished convex stainless steel surface, concave PTFE disc, lower bearing plate, and anchor bolt arrangement. Bridgent spherical bearings are manufactured to EN 1337-7.
Spherical bearings for bridge applications must comply with EN 1337-7 (Europe) or AASHTO LRFD Bridge Design Specifications (USA/international). Factory acceptance testing, including full-load compression tests and friction coefficient measurement, is mandatory.
Bridgent supplies spherical bearings with vertical load capacities from 500 kN to over 100,000 kN, manufactured and tested to EN 1337-7. Our engineering team provides full bearing schedule preparation, design verification services, and installation supervision for complex bridge projects worldwide.
Our engineers specialise in spherical bearing design for skewed, curved, and cable-stayed bridge structures. Contact us for a technical consultation.
Tags: Bridge Engineering Bridge Bearings Bridge Construction Bridge Maintenance Bridgent Products
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