New bridge expansion joints on the QEII Bridge
The installation of new bridge expansion joints on the Queen Elizabeth II Bridge at Dartford was completed in October 2014, in a project which has been recognised as the ‘Most Innovative Highway Authority Scheme of the Year’.
- 80 tonnes of steel
- 280 night shifts
- 458 bolts tightened on each installation
Six expansion joints, weighing 80 tonnes, are vital to the operation of the bridge, and had reached the end of their lifecycle.
Traffic flow continuity was critical during the project and with over 150,000 vehicles using the bridge every day.
A brand new temporary over-ramp system was developed, to allow the workforce to repair the expansion joints underneath, while traffic passed overhead, with only short night time, rather than lengthy all day closures needed to complete the 18-month project.
The ramp system was modular comprising 1.2 metre wide units which could be dropped into place, further reducing carriageway closure time. The built-in finger joints allowed the bridge road surface to expand contract normally and the design of the ramp allowed for vehicles to safely travel at speeds of up to 70mph, well in excess of the limit on the bridge and negating the need for vehicles to slow down on approach.
Each ramp was installed and removed four times requiring the removal and replacement of 458 bolts on each with around 100m3 of concrete removed during the repair process.
During the time the ramps have been in place approximately 30.2 million vehicles have driven over the ramp system leading judges at the Highways Magazine Excellence Awards on 21st October to comment that the ‘the innovative technique was carefully considered’ and had been ‘well organised in a time critical situation’.
The new innovative approach to the joint replacement also means improved safety for both the road user and road worker for the duration of the works, with minimal impact on the network and less exposure to live traffic for the workers. The system has been so successful that it will be adopted to replace movement joints at over 30 other locations on the M25 network during the duration of the DBFO contract.
The scheme was planned to last two years and was completed within 18 months, ahead of schedule. The work finished on the 18 October 2014.
- 639 briefings
- 581 inductions
- 30.2 millions vehicles driven over ramps