Published on 17 May 2010
Work has begun on site in South Queensferry to replace the bearings on the Forth Road Bridge's south approach viaduct.
The work forms part of a major project to replace all the bearings on both the approach viaducts both north and south of the Forth. The construction site has been fenced off for safety and scaffolding is being erected around the viaduct piers.
Preparatory works in North Queensferry are expected to begin during the summer, although the main works will not begin until early 2011.
Work on site is scheduled to continue through to the end of 2012.
The approach viaducts sit at either end of the bridge on each shore, connecting the A90 and M90 with the main body of the suspension bridge. Unlike the middle of the bridge, which hangs from the main suspension cables, the approach viaducts are supported by reinforced concrete piers. Steel bearings sit on top of these piers, allowing the deck to move as required by changes in temperature and traffic loading.
The project will involve jacking up the deck to allow removal of the existing bearings. The steel box girders that support the concrete deck will be strengthened at the jacking points, and reinforced concrete corbels added to the sides of the piers to accommodate the jacks, an alteration for which listed building consent has been granted. Concrete repairs will be carried out on the piers and a system of cathodic protection installed.
No disruption to daytime traffic is anticipated as a result of the bearing replacement project. However, some overnight restrictions may be necessary to ensure that the jacking and lowering of the bridge deck can be sufficiently controlled.
Further details:
- The best view of the Forth Road Bridge is from the rail bridge - new 360 view shows how elegant the structure is: http://t.co/TX7l54O2