SH25/SH25A Thames-Coromandel

30 October 2023

Current weather impacts

With the Coromandel Peninsula currently under an orange heavy rain and strong wind warning until Tuesday morning, road users are advised to take extra care and keep an eye on the Waka Kotahi journey planner for up to date information because the situation is changeable: https://www.journeys.nzta.govt.nz/journey-planner.

At various times on Monday flooding has closed SH25 at Manaia, Hikuai and just north of Whitianga. A close watch was also being kept on the Kauaeranga River.

SH2 was also under stop/go traffic management around 2km east of Paeroa on the approach to Karangahake Gorge, due to a small slip. 

If you have to drive, drive with caution as surface water remains in many areas and there may be debris on the road.

SH25A rebuild update

The first bridge deck panels were lifted into place over the past weekend, ahead of the wet and windy weather which lashed the Coromandel Peninsula on Sunday and Monday.

The team were able to lift and install 14 deck panels before weather conditions meant crane operations had to stop.

Three quarters of the concrete pre-cast deck panels and 16 of the pre-cast barriers are now on site waiting to be installed, with the remaining panels and barriers continuing to be fabricated off site.

Last week the team finished the bracing and pier connection work on the girders (beams) along the length of the bridge.

Abutment bearings were also installed last week. These bearings transfer the load from the bridge girders down into the concrete substructure. They also allow the steel girders to move as they expand and contract when subjected to changes in temperature. 

Settlement slabs were poured at both abutments. These concrete slabs are constructed full width across the roadway and extend out from the abutments to accommodate and smooth out any settlement that occurs in the road approach to the bridge. The goal is to avoid “bumps’ as you cross over onto the bridge.

Soil nailing across the slip face continues with the team using a man-cage mounted on a drilling rig.

The team has almost completed earthworks at the eastern approach to the bridge, which will allow us to start installing new culverts and side drains this week.

Top left: Bridge slabs being delivered to site last week. Top right: settlement slabs were installed at each abutment. Bottom left: photo taken from under bridge of new deck slab in place. Bottom right, wet and foggy conditions on site.

Stabilising the slip face

Soil nailing is continuing at mulitple locations across the slipface, with the crew needing to use a man-cage suspended from a drilling rig at times to access some higher areas.

A tale of two bridges

Steel plates bought for the Minden bridge on Tauranga’s Takitimu North Link project have taken a detour to a new destination – the State Highway 25A bridge build in the Coromandel.

The urgency of this work has meant the Waka Kotahi Coromandel team has had to take a dynamic approach to reconnecting both sides of the Peninsula. The problem: how to quickly construct a 124 metre, 3 span bridge with the expectation that the road will be open to traffic by March 2024?

This is where the Takitimu North Link project came into the picture, with Waka Kotahi agreeing to redirect the steel plates bought for one of the Minden Road bridges to fabricate the beams for the SH25A bridge instead.

These plates weren’t due to be fabricated into beams for installation at the Minden site until a next year so were able to be repurposed for SH25A and still replaced in time to meet their revised programme. The bridges on both projects are designed with steel beams of a very similar profile. There are slight dimensional differences however the steel thicknesses are equal for the most part.

It is a great example of collaboration and prioritisation to support those communities with the greatest need in a timely way. And frankly, the SH25A bridge wouldn’t be getting built this quickly as it is without this kind of thinking!

View how the steel plates are being used to fabricate the beams here. {https://www.youtube.com/watch?v=iZpzLHBsEsY}

Pictured below are the new bridge taking shape at SH25A Taparahi, and the new Minden bridge under construction.

SH25 Recovery Works

There are still multiple sites on SH25 needing repairs following the storms earlier this year. Repair works are being prioritised and sequenced to minimise disruption to traffic, particularly over the summer holiday period.  

Weather permitting, work is expected to start later this week at Ruamahanga – traffic will go down to a single lane there until just before Christmas as there will be workers on the slip face above the road. 

We also expect to be working on a further six further sites across the peninsula this side of Christmas, then recovery work which will cause traffic disruption, such as lane closures will be minimised until after Waitangi weekend.  

With works at the Coroglen underslip near completion, the next sites to start will be Wharekaho, Pumpkin Hill and Thornton Bay, followed by Kereta Hill and Te Kouma Hill.

Summer road maintenance programme underway

The next two months will see a flurry of chipsealing and asphalt surfacing taking place across the across the wider Waikato and Bay of Plenty region, alongside the larger infrastructure projects that continue as well.

This all contributes to improving the condition of the state highway network, resulting in smoother journeys for all.

Work has been planned to minimise delays, but given the volume of work, there are few sections of the network where people won’t experience some sort of disruption. It’s important during the summer months to factor in extra time to your journey, to ensure you arrive on time to your destination.

The Waka Kotahi Journey Planner (journeys.nzta.govt.nz) is the best place for information on the status of the state highway network. With live updates on worksites and other road hazards, Journey Planner can help road users plot the best route to their destination.

Works underway or about to start include:

· SH25 Thames:  Overnight road resurfacing on SH25, south of the Goldfields shopping centre for two weeks began on Sunday 29 October. Stop/go traffic management will be in place, and from time-to-time side roads will be closed so we can finish the work as quickly as possible. The affected side roads include Willoughby Street, Richmond Street and Sealey Street, access for residents will be provided from Pollen Street. Access to Richmond Street West will be maintained at all times.

·  SH26 Puriri: work to repair the road pavement will start on Monday 6 November at a site south of Kopu, near Puriri.  The work is expected to be completed within two weeks and will be undertaken using stop/go traffic management.

· SH2 Maramarua: Stop/go traffic management and a temporary speed limit will be in place from Monday 30 October to Thursday 2 November, between 9pm and 5am each night.

More information

For more information on the SH25/SH25A Thames-Coromandel project, contact us at coromandel@nzta.govt.nz

Visit our website www.nzta.govt.nz/thames-coromandel