23 June 2017

The Kaikoura earthquake landslides: an excellent video about the mitigation works on State Highway 1

Posted by Dave Petley

The Kaikoura earthquake landslides: an excellent video about the mitigation works on State Highway 1

The Marlborough Express has an excellent video online about the progress that is being made to mitigate the Kaikoura Earthquake landslides on State Highway 1 in New Zealand.  Unfortunately WordPress no longer allows embedding of this type of video, so you will need to look at the original news item to view it.

As the accompanying article notes:

It’s six months since the North Canterbury Transport Infrastructure Recovery (NCTIR) alliance was formed and despite a few setbacks State Highway 1, between Picton and Christchurch, is expected to open by the end of the year.

…opening the SH1 transport corridor brought more challenges and a design team was brought in.

“It was a complex job so we needed to make sure we planned it right and made the SH1 and rail network reliable and safe when we did open it,” [New Zealand Transport Agency earthquake recovery manager] Steve Mutton said.

Large slips north and south of Kaikoura had to be stabilised before work to clear the landslides could begin safely. For five months helicopters with monsoon buckets laden with sea water sluiced hillsides to loosen rubble and induce rockfall before a team abseiled in to dislodge and blast away larger rocks.

“Now it’s safe to have people underneath it so we’ve been moving slip material out and creating sea walls to bring the road and rail out from some of the larger slips,” Mutton said.

The article also provides some statistics:

  • 200 damaged sites, 100 damaged structures, 50 damaged retaining walls between Cheviot and Clarence
  • 40 damaged sites on the Inland Rd [the alternative road inland from the coast]
  • 10 major landslides north of Kaikoura, more than 30 south of Kaikoura
  • 69 road bridges affected – 2 require total replacement

The plan is to open both the railway and the road by Christmas.  The scale of the problem is enormous – this is just one of the many landslides that are having to be cleared for a new road and rail alignment to be constructed:

Kaikoura earthquake landslides

One of the Kaikoura Earthquake landslides that is being cleared. Image from Emma Dangerfield / Fairfax NZ