Sumner Road in Christchurch, New Zealand, reopened on 29 March, eight years since the critical road linking Christchurch, the Port of Lyttelton and the communities of Sumner and Lyttelton was badly damaged by the earthquakes that rocked the region in 2010–11.
The reopening marks the end of a very long and challenging project of repairing the road and retaining walls, as well as stabilising the rocky slopes above the road to protect against further rockfalls.
Leading global engineering and consulting firm Golder supported Christchurch City Council throughout the project, developing the preliminary design for measures to protect against rockfall along a circa 2 km stretch of the heavily damaged road, and also providing owner’s engineering advisory services throughout the 2.5-year construction period.
“The rockfall mitigation works involved scaling and blasting loose rock from the massive rock faces above the road, and construction of a wide catch-bench to prevent any future falls damaging the road again,” said Tim McMorran, Principal Engineering Geologist at Golder in New Zealand. “Once the rockfall mitigation was complete, the project extended into repairing 30 earthquake-damaged retaining walls and the road itself.”
Golder specialists maintained a presence on site throughout construction, representing the Christchurch City Council and guiding the work of contractors and subcontractors across a range of disciplines and activities.
“Golder thrived on the challenges of this important project, and the result demonstrates our strong values of safety, innovation, technical excellence and environmental stewardship in action,” said Hannah Hamling, Golder’s President in Asia Pacific. “We’re proud to see the successful and safe completion of this long and logistically difficult project which involved working in very complex terrain with unique biodiversity values.”
Due to Golder’s innovative design and expert advice, Christchurch City Council was able to complete the project for approximately two-thirds of the original cost estimate, saving more than NZD$15 million.
The dramatically beautiful coastal road is an important link between the communities of Sumner and Lyttelton and is a popular scenic tourist drive and cycle route. The reopening of the road has been eagerly awaited by the local communities and will allow tourists to return to the area, reduce local travel times and alleviate traffic pressure on the Lyttelton road tunnel.
Work on the road was jointly funded by Christchurch City Council and the NZ Transport Agency.