SH25A progress a ‘light at the end of the bridge’

Saturday, 19 August 2023

Seven months after cracks in an arterial Coromandel highway turned into a landslide, officials behind the construction of the SH25A bridge are “confident” the structure will withstand future storms.

After a series of devastating weather events formed a 130m wide and 30m deep hole, those behind the construction of the $48 million Taparahi bridge say they are on track to meet the anticipated March deadline.

On Friday government officials, along with media and local council staff, were given a first hand look at progress on the Taparahi bridge where towering cranes, cement trucks and crew were in action.

The tenure contracts were signed and construction was underway Waka Kotahi said after major stabilization works took place.

The agency estimated they were around 22% of the way through and in a few weeks time they would be at the stage where the stacking together of the “lego pieces” above ground would take place.

The bridge would have a “high level of resilience” with large cylinder piles which will form the base of the bridge being drilled around 35m deep into the slip’s foundations using a 100-tonne piling rig.

Prior to this 75 tonnes of cement had been injected into the slip material to retain and stabilise it.

“There will always be slips” Regional Manager of Infrastructure Delivery for Waikato/Bay of Plenty, Jo Wilton said.

But the agency was confident the bridge structure was sturdy and fit to face the uncertainty of future weather events.

The bridge was paramount to restoring access in the Coromandel Peninsula where a summer of eight storms had decimated the region’s roading network.

Those in the Thames-Coromandel District were a “resilient community” district Mayor, Len Salt said, but the bridge rebuild would be a silver lining for people.

“There’s this sense of light at the end of the tunnel or light at the end of the bridge if you like.

“There’s no doubt that this has had a massive impact on our community, but the fact that we’ve got the mobilization of Waka Kotahi and the government in behind this and things are moving, is really good.”

While at the tour on Thursday, transport minister David Parker, said he was “very confident” the bridge would be structurally sound.

“This is an enormous project, this bridge…is longer than a football field, they are going to deliver it by March next year and [Waka Kotahi] really rattled their dags to get this underway.”

Stabilizing the over-hanging embankment above the slip was also of priority, Wilton said, with water drainage being installed to divert running water away from the bridge site.

A bridge across the crater wide slip was always the quickest option and when weighed up against the other initial option of a bypass or a retaining wall, the bridge would be the more ecological and sustainable fit.

Construction of the 124m long and almost 16m high bridge had been moving at an “accelerated” pace never seen before, Hugh Milliken, Project Director MᶜConnell Dowell said.

Crew were working around 20 hours each day at the site while the bridge fittings were being made off-site so as to not halt construction.

But making sure the structure was safe, secure and future-proof was the ultimate focus.

“We’re moving very quickly, we’ve been made to move at a pace we’ve never done before.

“The welcome here from the local businesses has been great and the local community have been very generous with accommodation too.”

The formal paperwork for the preferred tenderer - a consortia of McConnell Dowell and Fulton Hogan, supported by Beca and Tonkin and Taylor had been finalised, Wilton said, after previously being still under negotiations.