Flintshire Bridge carries the A548 over the River Dee in North Wales and is the centrepiece of the Deeside Road Link project. The asymmetric cable-stayed structure proposed by our bridge engineers was selected through competition for its aesthetic appeal and economic viability. Our detailed design was the result of dynamic modelling, aerodynamic testing and load testing. Long term monitoring was also within our remit.
The 950m concrete crossing features a 118m tower supporting almost 200m of main span over navigable waterway. Located in the river, the tower was cast in situ and the foundations sunk into the underlying rock up to 65m. The deck was poured in 8m sections, cantilevering from the tower and supported by twin inclined planes of cable. An integral damping system was developed to stop excessive wind vibration in the cables, which were constructed on site using galvanised wire strand covered by HDPE duct.
A slim 1.5m deck meant the embankment heights were minimised, avoiding the need to raise overhead high voltage lines. Approach viaducts are comprised of multi-cellular RC box structures which were post-tensioned longitudinally.
- Design of road crossing, inclusive of cable-stayed structure, interchange structure and further minor structures.
- Early development of the scheme including taking through statutory process.