8 Dec 2017

Race to finish SH 1 north of Kaikōura

10:05 am on 8 December 2017

Workers rebuilding State Highway 1, north of Kaikōura, are racing to finish the job, with just one week left until the grand reopening.

Workers are racing against the clock to get the highway ready.

Workers are racing against the clock to get the highway ready. Photo: RNZ / Logan Church

The South Island's main transport corridor was devastated during a 7.8 magnitude earthquake last November, which knocked out bridges, tunnels, as well as large portions of the roads and rail line.

The road south of Kaikōura was reopened some time ago, but the route north, which saw nine major slips, was expected to open next Friday.

One of the worst slips was at Ohau Point, famous for its seal colony.

The earthquake brought down about 100,000 m3 of debris onto the road, much of which had to be moved using diggers, bulldozers and trucks.

Now, large concrete seawalls have been built to hold up the new road, and large barriers constructed to protect it against the hillside.

Workers are getting ready to seal the road.

One of the Ohau Point site managers, Clark Butcher, said it had been a hard push to the finish line.

"The earthworks and geotechnical teams has had significant technical challenges trying to stabilise the hill above us so we can move the road out on to the beach area that came out of the sea during the earthquake," he said.

"We've had to literally dig up the old seabed...we were below the high tide level so every high tide our worksite would flood and we had to pump it out to pour concrete footings the next morning."

Mr Butcher said there were many setbacks along the way, including the recent discovery of a spring where a large section of road was supposed to be built.

"It saturated the earth materials for over 100 metres...we stopped all of the traffic for a number of hours and threw all of the resources into getting this dug out," he said.

"We had guys getting out of the bed at two o'clock in the morning."

Mr Butcher said the road workers were on track to getting the highway open by next Friday.

One of the Ohau Point site managers, Clark Butcher.

One of the Ohau Point site managers, Clark Butcher. Photo: RNZ / Logan Church

Conquering Irongate

Several bridges along the coastal highway were also knocked out by the earthquake, but some had been rebuilt in record time.

Irongate Bridge, crossing the Irongate River, now holds the record for the fastest seven-span bridge (a bridge with seven main supports) built in New Zealand's history.

It was constructed in under three months, and consisted of 200 truck-loads of concrete, 91 bridge beams and 400 tonnes of reinforcing steel.

Its site foreman, Race Dill, had built over a dozen bridges back home in Canada, but he said he had not built a seven-span bridge as fast as this one.

"When you hear you are going to an area that was hit by an earthquake to build a bridge in a record space of time, you really don't know what to expect," he said.

"It takes a lot of planning and the right team to execute in what was an extremely truncated timetable."

Workers were now finishing of the top of the bridge, and constructing its sides ahead of the opening next week.

Mr Dill said the bridge was designed to keep road users safe in the event of another earthquake.

"The purpose of this bride is to get people out closest to the water and away from the hills that are prone to landslides," he said.

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