Installing Deep Ground Anchors in Challenging Conditions at the Northern Spire
Lloyds Civils were appointed by a joint venture of Farrans Construction and Victor Buyck to install temporary ground anchors on the Northern Spire Bridge at the New Wear Crossing, Sunderland.
Northern Spire, linking Castletown and Pallion, is the first bridge to be built in the city for more than 40 years. Its pylon is twice as high as the Millennium Bridge in Gateshead and taller than Big Ben’s clock tower. The central pylon stands at a height of 105 m (344 ft), making it the tallest structure in Sunderland.
Roughan & O’Donovan and Buro Happold delivered the preliminary and detailed design of the bridge.
Construction works begin in May 2015, with the bridge opening in August 2018. The centre pylon was fabricated off-site and floated to its location in February 2017. To raise the pylon, temporary anchor blocks were installed on the south abutment and used to install the winches. Blocks had to be anchored due to the forces need to lift the pylon.
Lloyds Civils installed 24 boreholes up to 33m in length through the blocks, glacial tills and Permian sands. Once a borehole was constructed, the team installed and
grouted in place Dywidags Multi Strand anchors.
All the anchors were tested, and two load cells were installed to monitor the anchors during lifting.
Before the pylon was lifted into place, test lifts were carried out to verify the loads being applied to the anchors. Engineers were able to view the load data and pylon lifting live through Lloyds Datum’s secure website.
Talk to our experts
This was a great project to be involved with. These were deep anchors in challenging ground conditions. Through testing and our partnership with LDG Datum monitoring, the client and engineers were pleased with the anchors and their performance during the lift, giving the site team the ability to access live load data during the lift was reassuring.
