Second Ashburton Bridge

Project update

21 October 2025

Kia ora koutou

We’re taking another important step towards building the new bridge, with the next phase of investigation work about to begin.

In July we finished geotechnical investigations in and around Ashburton/Hakatere River, which helped us understand what the ground is like beneath the surface.

Now we’re going to install a ‘trial pile’ by the river, at the end of the sealed section of Chalmers Avenue.

This will help us understand how the ground behaves so we can design the right piles to safely support the new bridge.

The results will help us decide the final design of the piles (deep bridge supports) and how far into the ground they’ll need to go – saving time during construction.

We’re aiming to start trial piling on 3 November, for about a week.

Read on to find out more about the trial.

Ngā mihi/Kind regards
2AB project team

What will happen?

A large steel pipe (1500mm diameter) will be driven around 20 metres into the ground using a crane-mounted hammer.

After the steel pipe is installed, we’ll drill out the material inside. We’ll then lift up and drop in a concrete plug with a steel top and hammer it down inside the pipe to test ground strength.

We'll be dontating the wood from the trees to the scouts.

We’ll also lay a gravel pad for the crane and piling rig (like the set-up in the picture). The pad provides a stable base for lifting heavy equipment and materials.

Work hours

We’ll be working Monday to Friday, 7am – 5pm (noisier work won’t start until 8am)

Our work is subject to weather and ground conditions which means it’s possible dates could change.

What to expect

There’s no getting around it – the hammering part is steel on steel. It will be loud at times, especially when the steel plug is hammered into place, and while it stays within safe decibel levels, the sounds cannot be fully mitigated.

All going to plan, we expect the loudest part of the work to be complete within four days.

If you’re near the work area you may notice some slight vibrations and humming.

The good news? This will be the closest piling work to residents during the entire project. The piling for the bridge will happen further away.
 

River tracks
Access along the river tracks will be unaffected. The only change will be the narrowed width of the access from Chalmers Avenue towards the river.

During certain activities, such as removing the pine trees, traffic control may briefly stop pedestrians for everyone’s safety and then allow people through as soon as it’s safe.

Co-ordinated construction
Our contractor and the contractor working on the Ashburton District Council water main renewals are aware of each other’s activities, and the work is being coordinated.

Completion of the ‘trial pile’

Once the work is completed, the steel casing will be cut off below ground level, the hole backfilled with the material that was excavated and the area returned to the condition before the trial started. Eventually, a new local road will be built over this location.

More information

We're here to help. If you have any questions or would like to speak with someone about this work, please contact us:

• Phone: 027 257 2249
• Email the team: 2AB@nzta.govt.nz

For more informattion about the project visit our website www.nzta.govt.nz/2AB