A180 bridge bearing replacement on Gilbey Road Bridge

The bearings under Gilbey Road bridge need to be replaced as part of the A180 bridges project.

This will involve a series of night time full carriageway road closures on the bridge in November and December. There will be a combination of closures that affect only one direction on some days or the entire stretch in both directions.

Bridge bearings are a vital component of a bridge which sit between the superstructure, or deck, and the piers or abutments of a bridge.

The key purposes of bearings are:

To transfer loads: Bridge bearings move loads from the bridge's deck to the substructure or piers. These loads include the weight of the structure, vehicle loads, and wind forces.

Allow movement: Bridge bearings allow the bridge deck to rotate and move, which helps the bridge adapt to external factors like temperature changes, and traffic.

Reduce stress: Bridge bearings help reduce stresses that can build up in the bridge structure.

The bearings on Gilbey Road bridge are made of steel and elastomeric materials. Different bridges have different types of bearings, and are dependent on several factors, including the expected load weights, the span length, and the available space for accessing the bearing. But over time, these start to wear out, and need replacing as part of general bridge maintenance.

In order to replace the bearings, specialist machinery is used to jack up the end of the bridge by a small amount, much as you would a car to change the tyre. The old bearing is removed and replaced with a new bearing, and the bridge superstructure lowered down again. This can’t be done with traffic on the bridge for safety reasons.

The night time closures are planned as follows to replace the bearings on the West and East abutments and Piers 1 and 2: