As part of the CityEdge Alliance, Tetra Tech Coffey undertook geotechnical investigations, detailed design, and construction phase services for this significant major infrastructure project in Waikato, New Zealand.
The project represents the teamwork and collaboration by the CityEdge Alliance to design and construct the Hamilton Section.
The CityEdge Alliance consortia comprised Tetra Tech Coffey, Fletcher Construction, Higgins Contractors, Beca, and Waka Kotahi NZ Transport Agency, with Hick Bros as a sub-alliance for the earthworks. We thank everyone who has worked on the project for their hard mahi over many years. The Hamilton section is the largest roading project ever undertaken in Waikato, connecting the Ngaruawahia section of the expressway in the north and the existing Tamahere section in the south. The highway travels through sensitive natural environments and difficult soft soils of the Waikato region. With over five million cubic metres of earthworks, material management was a major challenge, requiring extensive geoscience and soil management to reduce costs and minimise environmental impacts. In addition, there were complex drainage requirements due to low-lying saturated ground.
The team also faced considerable challenges from the Covid-19 pandemic and sustained periods of inclement weather. As part of the CityEdge Alliance, Tetra Tech Coffey undertook geotechnical investigations, detailed design, and construction phase services.
From 2016 until 2022, the project has had 7500 people work on it, constructing 22km of expressway, 16 bridges, a large underpass, 5 interchanges and 5.5 million cubic metres of earthworks, with the overall cost of the Hamilton section was NZ$837M.
With a number of areas of cultural significance along the alignment, the alliance worked closely with Waikato-Tainui on environmental and waahi tapu protection, archaeological interests, and creating training and employment opportunities. This project was one of true partnership with mana whenua, something that all who worked on the project can be extremely proud of.
The 102km four-lane highway reduces travel times between Auckland and Tirau by upwards of 35 minutes, and as each section has opened it has significantly reduced the number of fatal and serious injury crashes.
Location: Waikato, New Zealand
Duration: 2016 – 2022
Services provided: Geotechnical investigations, detailed design, and construction phase services.