Preparations underway for Wēiti Bridge

Initial work is well underway on the western side of the Wēiti River. This work will provide access to allow Waka Kotahi contractors to build the temporary staging that is needed to build the Wēiti River bridge, on the Stillwater side.

Construction of the temporary staging will begin in August and will take approximately six months to complete.

Although the 243m long platform is temporary, it is a significant build and Waka Kotahi estimates it will be there for around three-and-a-half years.

It involves shifting 20,000 cubic metres of soil. The platform will have 64 piles, each with a 762mm diameter. The maximum pile depth will be 17m in the middle of the Weiti River.

A 280 tonne crane will be used to carry out work for the platform.

Waka Kotahi says the bridge itself will be the first of its kind built in New Zealand. It is called an ‘extradosed’ bridge, described as a hybrid between the more traditional box girder and cable-stayed bridge designs. The box girder element means it can carry a range of services and utilities, such as power and water, to Whangaparāoa Peninsula. There’s also space for a future sewer main.

The cables allow for a longer bridge span which reduces the number of piers needed to support the bridge and thus reduces the impact on the river below.

The span arrangement enables the piers to be clear of the navigable waterway and is more respectful of ecological and cultural site constraints.

The reduced number of piers and removal of the centre pier allows clearer views and passage through the navigation channel. Improved construction methodologies, including a reduction in temporary staging, helps to minimise greenhouse gas emissions.

A lowered entrance to the crossing fits better with the landscape, enabling 235 metres to be trimmed off the overall crossing and reducing the amount of steel and concrete required.

A reduction in the amount of concrete required significantly reduces construction emissions.

Other winter works on O Mahurangi

Penlink sites include access tracks and site access points, ground improvements and tree felling. Test pits have been dug on sections of Ara Wēiti and Whangaparāoa Roads as part of geotechnical investigations. The pits allow geotechnical experts to assess the ground for the upcoming road works and see if it’s suitable. The information gathered ensures the infrastructure is built safely and effectively.

A mahi toi (artwork) for the AraTūhono – Pūhoi to Warkworth motorway project was unveiled at a dawn ceremony last week. It forms part of a series of artworks along the road, which reflect the history and values of mana whenua in the area. The two elements are a four-metre carved pou whenua and a stainless steel pouākai giant extinct eagle. The po whenua was designed and crafted by Wyvern Rosieur (Ngāti Manuhiri), while the pouākai is the work of Nathan Hull. The artwork is a tribute to Reipae – Tohitohi o Reipae Dome Valley takes its name from the Tainui ancestress Reipae. Reipae and Reitū (her sister) travelled on the back of a large pouākai and rested in the area on their way to Whangarei. The smaller carving at the foot of the pou reflects the lives lost on the old stretch of road. “Reipae is here to protect and guide the spirits of those who have passed away, and to comfort their loved ones,” Wyvern says. The artists who worked under Wyvern were Uenuku Hawira (Ngāti Amaru), Hokimai-Anahera and Rerekapua Rosieur (Ngāti Manuhiri) and John Antonovich (Ngāti Manuhiri).