A £6 million scheme on the M4 to strengthen the Ebbw River Bridge and improve safety is progressing well.
The bridge carries the M4 motorway over the River Ebbw, north of junction 28 Tredegar Park. Approximately 500,000 journeys take place on this busy section of the network per week. This work will reduce the risk of unplanned closures and allow these journeys to continue safely.
A time lapse video of Ebbw River has been released which shows the 20-tonne strengthening beams being dropped into position by a crane.
The South Wales Trunk Road Agent (SWTRA) and their partners, WSP and Alun Griffiths Contractors have developed an innovative strengthening design and construction methodology which allows the bridge to be kept in service during construction.
This helps to minimise the number of closures needed and limits them to only take place overnight, which will reduce traffic disruption and improve road safety.
The work, which began last year, involves site clearance including invasive species like Japanese knotweed, which will improve biodiversity in the surrounding area.
Leading the way on wildlife and the environment
Positive impacts on the local environment have already been seen as a pair of nesting grey wagtails made the bridge their home for a short time. Workmen were careful not to impose on the nest and were able to complete other minor work until nature took its course and the birds flew on.
The wildlife near the bridge is an incredible asset; species such as heron, kingfisher and otters have also been seen alongside Ebbw River and surrounding areas. Ecologists have been working closely with the project team to ensure that the wide range of protected species along the route are cared for.
Reinforced concrete leaf piers have been constructed at either end of the bridge. These new piers encapsulate the old columns to create one large pier and will be used to support a steel strengthening frame which will prop up the bridge. Used pallets from the works site have recently been donated to a primary school in Torfaen to make outdoor kitchens.
What’s still to be done
Narrow lanes between junctions 26 and 28 on the M4 are required as a mitigation measure to keep the bridge in service during these works. The bridge is being constantly monitored with remote monitoring gauges until a deck replacement is undertaken. Traffic management around the M4 junction 28 Tredegar Park will also continue to allow site access from the eastbound on slip at all times during the construction.
Towards the end of July a frame will be jacked up against the structure, to support the centre span of the bridge. This will be followed by the removal of temporary works, scour mitigation and restoration works over the autumn.
Further details will be published by Traffic Wales closer to the time. Drivers using the M4 are urged to check the website and @TrafficWalesS on Twitter before travelling for the latest traffic and progress updates for these works.