A 1,100t crawler crane has lifted into place a 90.5m arch bridge over the Wairoa River in New Zealand.
The structure, designed by WSP and commissioned by Wairoa District Council, replaces the Te Reinga Bridge that was damaged beyond repair by Cyclone Gabrielle in 2023.
QRS (owned by WDC) is the lead contractor, and the structure was designed by WSP. Involved in the lift were Brian Perry Civil, Smith Cranes, and steel fabricator Eastbridge.
WSP principal bridge engineer Daryn Hobbs said, “The arch steelwork without the concrete deck is relatively flexible, and we could see certain hangers tighten and loosen as the load path shifted during the lift and set down. We knew that behaviour and the deflections observed were expected, but being there was important to reassure the crane supervisor.”
He added that early contractor involvement has helped the success of the project.
The new arch of Te Reinga Bridge (Wairoa District Council)
The new bridge has a 100-year design life and its foundations are built to stabilise the riverbank. Its single span means that there was no need to place piers in the riverbed, giving more clearance during floods. An arched structure was selected to address risk around slope stability. To better manage maintenance, weathering steel was used; and the hangers can be removed and replaced while the bridge continues to carry traffic.
A temporary Bailey bridge will be removed in due course. Next on the to-do list is constructing the 14m concrete land spans, finishing the abutments, constructing and surfacing the deck, and erecting barriers.
